Soil liming effects on CH4, N2O emission and Cd, Pb accumulation in upland and paddy rice

Accepted Manuscript Soil liming effects on CH4, N2O emission and Cd, Pb accumulation in upland and paddy rice Muhammad Athar Khaliq, Muhammad Waqas Khan Tarin, Guo Jingxia, Chen Yanhui, Wang Guo PII:

S0269-7491(19)30086-7

DOI:

https://doi.org/10.1016/j.envpol.2019.02.036

Reference:

ENPO 12205

To appear in:

Environmental Pollution

Received Date: 6 January 2019 Revised Date:

5 February 2019

Accepted Date: 13 February 2019

Please cite this article as: Khaliq, M.A., Khan Tarin, M.W., Jingxia, G., Yanhui, C., Guo, W., Soil liming effects on CH4, N2O emission and Cd, Pb accumulation in upland and paddy rice, Environmental Pollution (2019), doi: https://doi.org/10.1016/j.envpol.2019.02.036. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

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Soil liming effects on CH4, N2O emission and Cd, Pb accumulation

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in upland and paddy rice

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Muhammad Athar Khaliq1, Muhammad Waqas Khan Tarin2, Guo Jingxia1, Chen Yanhui1, Wang

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Guo1*

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35002, China.

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Abstract

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Keeping in view the expanding environmental pollution and irrigation water deficit, a pot

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experiment was performed for the upland (Huyou2, Hanyou737) and paddy rice cultivars

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(Taigeng8; Yixiang2292), to study soil liming effects on methane (CH4) and nitrous oxide (N2O)

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emission, bioavailability and accumulation of Cd, Pb in upland and paddy rice. Upland rice

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reduced 90% of soil CH4 emission as compared to paddy conditions. Soil CH4 emission

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decreased by 45% and 39% with dolomite, and it reduced by 35% and 33% with lime treatment

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both in upland and paddy conditions, respectively. Soil N2O emission decreased by 44% and 52%

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with dolomite, and with the lime application, it was reduced by 37% and 44% for both upland

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and paddy conditions respectively. Reduction in DTPA-extractable Cd was between 37-53% and

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43-80% with dolomite and 16-37% and 24-72% Cd decreased with lime application in upland

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and paddy conditions respectively. Soil DTPA-extractable Pb reduced by 27-44% and 25-53%

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with dolomite and 16-40% and 11-42% with soil-applied lime in upland and paddy conditions,

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respectively. Cd accumulation in rice grain was decreased by 47-88% and 62-79% with dolomite

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College of Resource and Environment, Fujian Agriculture and Forestry University, Fuzhou,

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Fujian Agriculture and Forestry, University, Fuzhou, Fujian 35002, China.

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and 31-86% and 45-52% reduction by lime application in upland and paddy rice respectively.

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Rice grain Pb reduced by 58-91% and 66-78% with dolomite application and 32-71% and 44-71%

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with lime in upland and paddy rice, respectively. Our results showed that soil liming

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significantly reduced soil N2O and CH4 emission and Cd, Pb accumulation in rice grain, but

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dolomite was more effective as compared to lime. Altogether, results of this study suggest that

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upland rice can be cultivated in Cd-Pb polluted soils with least soil CH4 emission. Cd and Pb

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toxicity, accumulation, and N2O emission in upland rice can be minimized by soil liming of 3 g

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kg-1 and optimizing the nutrients composition of the soil.

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Keywords: Upland rice, greenhouse gases, heavy metals, LA-ICP-MS, soil liming.

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Major findings: Upland rice has the capacity to decline CH4 emission and soil liming can

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reduce N2O emission in upland rice.

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1. Introduction

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Rice being the highest water-demanding crop, about 50-70% of water can be saved by growing

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upland rice as compared to paddy rice (Teng et al., 2014). The increasing water scarcity can be

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alleviated by developing an alternate rice production system for water saving and upland rice

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production system is one of them (Wang et al., 2002). Thus, by developing new strategies for the

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rice cultivation by adapting upland rice as an alternate in water deficit areas. The paddy rice is

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considered as a significant source of methane emission (IPCC, 1996) but the upland rice

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production system not only conserve water but also reduce the methane (CH4) due to aerobic soil

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conditions. CH4 is produced by methanogen bacteria in paddy soils at low (-150 mV) redox

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conditions (Sass, 1997). The continuous submerged conditions of paddy fields lower the redox

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potential which promote the organic matter decomposition by methanogenic bacteria. Two major

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pathways of CH4 production in the paddy fields are the decarboxylation of acetic acid and the

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reduction of CO2 with H2 derived from the organic compounds (Aulakh et al., 2001). The major

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source of CH4 emission in rice soils is the top-soil just below the oxic layer (Mitra et al., 2002).

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Under the soil aerobic conditions, CH4 undergoes oxidation process by methanotrophic bacteria

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(Aulakh et al., 2001). Transfer of paddy rice system to the upland rice production system, with the

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soil moisture change, causes a significant reduction in CH4 emission but promotes N2O

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production and emission due to aerobic conditions. N2O emission occurs as a result of

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nitrification and denitrification processes and both have different optimum soil moisture levels.

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About 50% of water filled pore spaces (WFPS) for the nitrification process and >80 % WFPS is

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optimum for denitrification process (Davidson, 1993a). Consequently, wetting of dry soils may

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also cause increase in N2O emission (Davidson, 1993b). As the soil N2O is emitted via diffusion,

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but the increase in soil moisture reduces nitrification and induces denitrification process, results in

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the reduction of N2O emission due to reuse of NO3- (Hou et al., 2000).

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It is estimated that more than 10% of Chinese agricultural soils are contaminated with heavy

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metals (Zhao et al., 2015). Heavy metals such as Cd and Pb have been released into the

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agricultural soils, particularly in the areas affected by mining and smelting activities. Cd and Pb

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have been the most toxic elements and have been shown to be the non-biodegradable and

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extremely persistent in acidic soils (Yang et al., 2018). These contaminants in the soil pose

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adverse and even disastrous effects on human health via soil-food chain (Yang et al., 2017). In

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general, soil acidification enhances the solubility of certain toxic metals and essential nutrient

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elements, causing nutrition imbalance in plants (Sharma et al., 2008). Soil acidification was found

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to increase the solubility of Cd, Pb, and Zn to a certain pH level (Komarek et al., 2008), but Mn

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solubility reached to the toxic level (Yang et al., 2005). Dolomite and lime application to the soil

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improves chemical and biological properties of the soil. The greenhouse gasses emission (CH4

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and N2O) and heavy metals (Cd and Pb) availability and accumulation are soil pH dependent

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(Hong et al., 2007; Saari et al., 2004) soil Eh (Zaw et al., 2018); soil moisture and soil

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temperature (Luo et al., 2013). Liming is also widely recommended strategy to reduce mobility

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and availability of soil contaminants such as Cd and Pb and their accumulation in plants

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(Wiechula and Loska, 2000; Yang et al., 2018). Lime application not only increases the soil pH

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but also influences other soil properties, the concentrations and transformation processes of NH3+,

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NH4+ and NO3- (Kirchmann and Witter, 1989; Thangarajan et al., 2013) and production and

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oxidation of CH4 (Page et al., 2009). Soil moisture not only act as a transport medium for NO3-

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and NH4+, it influences O2 supply rate and thus controlling aerobic and anaerobic processes

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within the soil (Zou et al., 2005).

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Upland rice has similar yield potential and grain quality with paddy rice but requires less

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water. Hence, appropriate fertilizer application, water management (Smolders et al., 2009),

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together with liming amendments can be useful to reduce CH4 and N2O emission (Shaaban et al.,

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2015b, 2015a; Shaaban et al., 2014) and heavy metals phyto-availability and accumulation in

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upland rice (Bolan et al., 2003). Literature regarding lime and dolomite application effects on the

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CH4 and N2O emission and Cd, Pb accumulation in upland rice system is scared. We

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hypothesized that the application of lime and dolomite could reduce CH4 and N2O emission and

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decrease Cd, Pb availability and accumulation in rice. Therefore, a comparative study was

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conducted to check the effects of soil applied lime and dolomite on CH4 and N2O emission and

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Cd, Pb availability and accumulation in upland and paddy rice into an acidic soil.

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2. Materials and methods

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2.1. Pots preparation

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The soil used for the pot experiment was collected from Nanya village, Jianou county, Nanping

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city, Fujian province (Fig. 1), containing 2.18% clay; 20.64% silt; 47.38% fine sand and 29.79%

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coarse sand. The soil was naturally contaminated with Cd and Pb, with pH = 4.5, DTPA-

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extractable Cd = 1.21 ± 0.01 mg kg-1 and DTPA-extractable Pb = 355.65 ± 0.50 mg kg-1. Air-

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dried soil (uniformly mixed) was passed through 2-cm sieve and closed bottom pots were filled

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with 9 kg/pots. A recommended dose of basal fertilizer (urea = 2.57 g/pot; NH4H2PO4 = 1.41

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g/pot; K2SO4= 2.57 g/pot) with two amendments; dolomite (CaMg CO3)2 and limestone (CaCO3)

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under three levels (0, 1.5 and 3 g kg-1) were incorporated to each replicate. The pH of the lime

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and dolomite powder (powder:water = 1:2.5, w/w) was 10.3 and 12.5 respectively. The mixed

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soil was placed 10 days before transplanting with a thin layer of water (～3 cm above soil

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surface) for paddy rice and wet condition (about 70% field water capacity) for upland rice were

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kept during the whole rice growth period. At tillering stage recommended dose of (urea = 2.06

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g/pot; NH4H2PO4 = 1.16 g/pot; K2SO4= 2.06 g/pot) was applied to each pot. Recommended dose

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of urea = 0.52 g/pot; NH4H2PO4 = 0.26 g/pot; K2SO4= 0.52 g/pot was applied at heading stage

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and hand weeding was conducted before fertilizers application at every stage. Suitable pesticides

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were used for controlling the pests, in case of any pest’s attack. The liming amendments

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(dolomite and limestone powder) were purchased from the Xinchuan mineral processing plant,

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Hebei province, China.

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2.2. Seed preparation and growing of rice crop

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Two upland rice cultivars (Huyou2, Hanyou737) and two paddy rice (Taigeng8; Yixiang2292)

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cultivars were grown in closed bottom plastic pots (40 cm × 30 cm × 17 cm). Rice seeds were

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first washed with ultra-pure water to remove suspended seeds. The washed seeds were then

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soaked in 30% hydrogen peroxide solution (analytical grade) for 30 min to make it disinfectant,

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and then washed with deionized water for two to three times. The cleaned rice seeds were placed

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into the centrifuge tubes, dipped in ultra-pure water in growth chamber for two days. After two

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days, paddy rice cultivars seeds were spread into the pots containing the same soil used for this

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experiment but the 8 upland rice seeds were directly applied to every pot for each cultivar. Paddy

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rice nursery was transplanted into the pots, after few days thinning of both upland and paddy rice

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was done and four plants were kept in each pot. The productive tillers were counted at maturity

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stage.

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2.3. Moisture control

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In upland rice, wet conditions (about 70% of the field capacity) were kept during the whole

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growth period. Field water capacity of the soil was measured before starting the experiment. The

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weight of pot+soil+water (70% FWC) was measured in advance for each pot and soil moisture

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meter was also used at the same time to measure the soil moisture. The amount of water was

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controlled by weighing the pot+soil+water and with the moisture meter throughout the crop

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growth period.

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2.4. Dry matter production and rice yield

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Number of productive tillers, fresh and dry weight of root, shoot and grain were calculated as

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described by Yang et al., (2016). Fresh weight of roots, shoots and spikes were determined and

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later dry weight of root, shoot and husked rice were determined after drying at 60º C for dry

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matter and rice yield.

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2.5. Soil and plant sampling

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Soil and plant samples were collected at the time of rice maturity. After harvesting rice crop,

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Fresh soil samples were collected from the upland rice pots and stored at 4° C but paddy rice

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pots soil was mixed thoroughly and left them in the greenhouse to dry the standing water. When

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there was no standing water on soil surface, then soil samples were collected from these pots and

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stored them at 4° C for the analysis. Another group of soil samples from all the pots were

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collected and dried at room temperature, grinded and sieved for soil organic matter and soil

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particle size distribution. Fresh rice roots were harvested and preserved into the icebox and

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transferred them to the lab and stored at -80° C. Rice roots, shoots and spikes were separated.

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Roots and shoots were washed with tap water to remove the soil, twice with distilled water and

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then with ultra-pure water (Resistivity: 18.25 MΩ cm). Shoots were separated into stem and

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leaves and let them remove the water after washing. Roots, stem and leaves were put into an

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oven at 60° C for drying. The dried rice parts were pulverized into a powder by using stainless

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steel grinder and then stored for chemical analysis. Rice spikes were dried at 30° C to remove the

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extra moisture. Dried spikelets were subjected to the hand de-husking and good quality clean

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seeds were selected for the chemical analysis.

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2.6. Soil and plant metals extraction and analysis

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Soil pH was determine according to Athar et al., (2019), using a pH meter (Seven Compact;

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Mettler-Toledo, Greifensee, Switzerland) in 2.5:1 water/soil suspensions. Soil organic matter

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content was determined using an element analyzer (Vario Max Cube, Elementar, Germany). Soil

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particle-size distribution was determined using Laser particle size analyzer (BT-9300ST, Better

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size, China). Soil moisture contents of the fresh soil was measured then converted to soil dry

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weight equivalent for the fresh soil analysis. Fresh soil was used to determine soil pH, and Eh

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was measured from the pots by using Eh meter (FJA-6; Chuan-Di Nanjing China). Soil NO3--N

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and NH4+-N were extracted by using 0.01M KCl solution (Lithium acetate used to stop

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interference between NH4+, K+, Na+). Fresh soil was used for NO3--N and NH4+-N extraction

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with 1:10 (soil/solution) was shaken for 1h, centrifuged and filtered for the subsequent analysis.

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NO3--N and NH4+-N concentrations were measured using ion chromatography (Thermo ICS-

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2100; Thermo Fisher Scientific, NY, USA).

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Bioavailable Cd and Pb in the soils were extracted using a DTPA solution (diethylenetriamine

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pentaacetic acid, 0.005M; CaCl2, 0.01M; triethanolamine [TEA], 0.1 M; pH=7.3), according to

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the following procedures: 5.00g air-dried soil (<2 mm) was mixed with 25 mL of DTPA solution

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(Athar et al., 2019; Li et al., 2016). The soil suspension was continuously shaken at 25°C for 2 h

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and then immediately filtered and stored for further analysis. The dried plant parts were digested

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by using 0.1 g of root and stem, 0.2 g of leaf and 0.5 g of brown rice was digested with 4 mL

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HNO3 and 1 mL H2O2 by using a microwave digestion system (MARS6; CEM, USA) (Athar et

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al., 2019). Following the digestion, solution was transferred into 100 mL flasks for root and stem,

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50 mL flasks for the leaf and 25 mL volumetric flasks for brown rice samples and the volume

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was achieved by using ultra-pure water. The solution was filtered through a Millipore filter (0.45

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µm) and stored in plastic bottles for subsequent analysis. The Cd, Pb, Fe, Zn, Mn, Ca, and Mg

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concentrations were measured using an Induced Couple Plasma-Mass Spectrometer (ICP-MS,

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NexION 300X; Perkin Elmer, NY). High concentrations elements were measured by using flame

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atomic absorption spectrometry (PinAAcle 900; Perkin Elmer, USA).

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2.7. Roots sample preparation for LA-ICP-MS analysis

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Upland and paddy rice root samples were prepared as stated by Athar et al., (2019). Fresh rice

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roots stored at -80º C were used to prepare slides to allow visualization of the distribution of Cd,

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Pb, Fe, Zn, Mn, Ca, and Mg using Laser Ablation Inductively Coupled Plasma Mass

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Spectrometry (LA-ICP-MS). Selected root samples were washed with ultra-pure water

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(Resistivity: 18.25 MΩ cm). The washed rice roots were frozen in a Tissue-Tek O.C.T

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Compound (Sakura Finetek, Torrance, CA, USA) and cut into cross-sections of 60 µm thickness

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with a freezing microtome (CM1950; Leica Biosystems Wetzlar, Germany) at -25° C using a

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low-speed, steel blade saw. These slices were transferred onto the slides for analysis by laser

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ablation (LSX-213 G2+, Teledyne Photon Machine, Bozeman, MT, USA) coupled with ICP-MS.

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The laser ablation was conducted using a spot size of 10 µm and the scan rate of 10 µm S-1 with

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laser energy of 35% and a laser shot frequency of 20Hz.

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2.8. Measurement of CH4 and N2O fluxes

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Gas samples were collected throughout rice growth period after every two weeks between local

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time (09:00 – 11:30) from mid-July, 2017 to end September, 2017. Soil pH, Eh and temperature

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were measured with a 5 cm depth from each pot at the time of gas sampling. N2O and CH4 were

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measured using closed polyvinyl chloride chamber with an open bottom of the cubic chamber

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(height = 19 cm, circumference = 50 cm, diameter = 16 cm). Samples were taken with 100 mL

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plastic syringes attached with a three-way stopcock at 0, 20, 40, 60 min following chamber

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closure, respectively. Gas samples were analyzed within 24 h using a modified gas

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chromatography system (Agilent 7890B, USA) equipped with an electron capture detector

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(ECD) and flame ionization detector (FID), respectively. Detail of measuring system and

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associated method have been described by Wang and Wang, (2003). Gas fluxes inside the

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chamber against the closure time according to the following equation;

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F = ρ V/W × (dCt/dt) × 273 (T + 273)

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Where, F is CH4 and N2O gas flux (µg Kg-1 h-1), ρ is gas density at standard conditions (mg m-3),

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V is chamber volume available (m3), W is the weight of the soil per pot (kg), T is absolute air

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temperature in the chamber at the time of sampling (oC), Ct is the concentration of mixed volume

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ratios of gases in the chamber at time t (10-6).

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Cumulative gas fluxes (µg kg-1) were calculated using fortnight emission over the whole crop

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period as described by (Shaaban et al., 2014).

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=

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×

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Where “Ri” is the gas emission (µg kg-1 h-1) of sampling dates, “Di” is the number of days in the

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sampling interval and “n” is the number of sampling times.

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2.9. Quality control and data analysis

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Quality control was assured as in the first experiment. Experimental data was analyzed using the

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IBM SPSS statistics program to determine variance (ANOVA), Microsoft Excel-2016 was used

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to determine the correlation coefficient between soil properties and CH4 and N2O emission and

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soil DTPA-extractable Cd and Pb. Sigma plot 12 was used to draw the figures and the elemental

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bio-images were plotted using Origin Pro (version 8, Northampton, MA, USA).

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3. Results

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3.1. Changes in soil properties after lime and dolomite application

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Without the application of lime and dolomite, soil pH for both upland and paddy rice were

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significantly different during rice growth period (Table 1). Application of lime and dolomite

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increased soil pH. Average soil pH increased from 4.73 to 5.44 and 6.47 with dolomite

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application and 4.73 to 5.38 and 6.36 with lime application in upland rice. In paddy rice, soil pH

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increased from 5.06 to 5.80 and 6.83 with dolomite application and 5.06 to 5.65 and 6.70 with

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lime application respectively (Table 1). Soil CEC for upland and paddy rice was not significantly

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different during rice growth season (Table 1). Lime and dolomite application increased soil CEC

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significantly (P≤0.05). Average soil CEC increased from 37 to 47 and 58 cmol(+)/kg and 37 to

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46 and 54 cmol(+)/kg with 1.5 g and 3.0 g of dolomite and lime application respectively, in

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upland rice. In paddy rice; soil CEC increased from 38 to 45 and 53 cmol(+)/kg with dolomite

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application and 38 to 43 and 50 cmol(+)/kg with lime application of 1.5 g and 3.0 g respectively

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(Table 1). Soil organic matter (SOM) was high in upland conditions as compared to paddy soil

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but no significant differences were found. SOM was low in control treatment in upland and

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paddy rice but SOM increased from 20 to 20.63 and 21.05 g kg-1 with dolomite application and

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20 to 20.66 and 20.93 g kg-1 with lime application but no significant differences found between

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dolomite and lime application in upland rice soil. Similarly, SOM increased from 20 to 20.50 and

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20.88 g kg-1 with dolomite and 20.44 and 20.69 g kg-1 with 1.5 g and 3 g of dolomite and lime

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application respectively, but no significant differences were found with lime and dolomite

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application in paddy conditions (Table 1). Soil temperature changes with changing weather

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conditions. There was a significant (P≤0.05) positive relationship between soil temperature and

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CH4 and N2O emission (Table S1, S2 & S3).

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3.2. Dry matter production and rice yield

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There was no substantial effect of low lime and dolomite treatment on dry matter production and

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rice yield. There was a significant and positive effect of high rate of lime and dolomite

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application on dry matter production and no significant increase in rice yield of upland rice

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compared to paddy rice cultivar (Taigeng8)(Table S4). There was significant and positive effect

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on rice yield of Yixiang2292 as compared to control treatment (Table S4).

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3.3. Soil concentration of NH4+-N and NO3- -N

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Soil NH4+-N and NO3--N concentration was significantly affected by the addition of dolomite

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and lime. Results showed that NH4+-N and NO3--N increased by lime and dolomite as compared

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to control in both upland and paddy rice (Table 1). There was a high concentration of NH4+-N in

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paddy conditions as compared to upland but NO3--N was low in paddy soil and high in upland

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conditions. In upland, soil NH4+-N increased significantly from 0.32 to 0.89 mg kg-1 with

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dolomite, but in lime treatment, it was 0.62 mg kg-1. Soil NO3--N concentration increased from

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5.60 to 6.82 with dolomite and from 5.60 to 6.63 with lime application in upland conditions

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(Table 1). In paddy conditions, soil NH4+-N was increased from 0.98 to 1.82 mg kg-1 in dolomite,

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but it was 1.71 mg kg-1 with soil-applied lime. Soil NO3--N was highest in soil-applied dolomite

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(4.97 mg kg-1) but with lime, its concentration was 4.36 mg kg-1 as compared to the control (2.69

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mg kg-1) in paddy conditions (Table 1).

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3.4. CH4 emission

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At an early growth stage, there were high peaks of CH4 emission in both upland and paddy

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conditions, which may be due to high atmospheric and soil temperature. Total CH4 emission in

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the control treatment was the highest and the lowest in dolomite treatment both in upland and

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paddy soil (Fig. 2.ab). A cumulative mean of CH4 was 2284 µg kg-1 in paddy rice but it was 74

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µg kg-1 in upland rice (Table 1). A decrease in soil moisture (aerobic conditions) and the addition

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of lime and dolomite significantly (P ≤0.05) influenced CH4 emission. Upland rice reduced up to

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90% CH4 emission as compared to paddy soil of control treatment. Total CH4 emission reduced

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by 46% with the lime application and 52% with dolomite application of 3 g kg-1 of soil (Fig. 2.b).

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There was a reduction of 37% CH4 emission with lime and 43% decrease with dolomite addition

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of 3 g kg-1 of soil in upland rice (Fig. 2.a). So, the dolomite was more effective as compared to

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lime both in upland and paddy soil. According to the correlation analysis results, CH4 emission

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was more significant and positively correlated with soil temperature in paddy rice (r = 0.675;

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P≤0.05) as compared to upland conditions (r = 0.558; P≤0.05). In control treatment, there was

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significant negative correlation with soil pH in paddy conditions (r = -0.604; P≤0.05), but no

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significant correlation found in upland conditions (Table S1).

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3.5. N2O emission

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At early growth stages, there were high peaks of N2O in both upland and paddy conditions may

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be due to more availability and less use of fertilizers by rice and high atmospheric and soil

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temperature. N2O emission was highest in control treatment of upland rice as compared to paddy

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control treatment (Fig. 3.ab). A cumulative mean of N2O was 1132 µg kg-1 in upland rice but the

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cumulative mean of N2O was 393 µg kg-1 in paddy rice (Table 1). Addition of lime and dolomite

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significantly (P ≤0.05) reduces N2O emission. In upland rice N2Oemission reduced by 41% with

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the addition of 3 g kg-1 of lime and dolomite resulted in 48% decrease of total N2O emission (Fig.

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3.a). Lime application reduced by 40% N2O emission and 46% N2O reduction with 3 g kg-1 of

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soil applied dolomite in paddy conditions (Fig. 3.b). Results showed that dolomite treatment was

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more efficient as compared to lime treatment in both upland and paddy conditions.

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N2O emission was significantly and positively correlated with soil temperature (r = 0.775; P≤0.05) and soil NH4+ concentration (r = 0.867; P≤0.05) but negatively correlated with soil pH

286

(r = -0.551; P≤0.05) and soil NO3- concentration (r = -0.946; P≤0.05) in upland conditions

287

(Table S2). Correlation was more significant with the application of lime and dolomite. In paddy

288

conditions, there was significant positive correlation with soil temperature (r = 0.619; P≤0.05)

289

and soil NH4+ concentration (r = 0.910; P≤0.05) but negative correlation with soil pH (r = -

290

0.739; P≤0.05) and soil NO3- concentration (r =-0.932; P≤0.05) (Table S3). In paddy condition

291

soil pH and NH4+ correlation was weak but the soil pH and NO3- correlation become more

292

significant with the application of lime and dolomite (Table S3).

293

3.6. Soil DTPA-extractable Cd, Pb and their accumulation in rice

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Lime is well known to increase soil pH and decrease the availability of some heavy metals and

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their accumulation by paddy rice. Comparison of upland and paddy rice to absorb Cd and Pb

296

from the soil and their accumulation in various parts of both upland and paddy rice plant were

297

evaluated (Table 2 & 3). The concentration of Cd and Pb in various parts of upland and paddy

298

rice and soil-DTPA Cd and Pb decreased with increasing lime and dolomite addition. The Cd

299

and Pb content in different parts of upland and paddy rice decreased in the order of root> stem>

300

leaf> brown rice (Table 2 & 3). The majority of Cd and Pb were held in the roots, which varied

301

with upland rice cultivars. The contents of Cd and Pb in the roots decreased in the order of

302

Hanyou737> Huyou2> Yixiang2292> Taigeng8. Lime addition decreased only Cd in brown rice,

303

while dolomite reduced both Cd and Pb in brown rice of upland and paddy rice cultivars (Table 2

304

& 3). The highest dose of dolomite decreased Cd and Pb below the Chinese limits for rice (GB

305

2762-2017) whereas lower rates of lime and dolomite cannot reduce the contents of Cd and Pb

306

below the limits (Table 2 & 3). The Cd and Pb concentrations in brown rice were significantly

307

correlated with DTPA-extractable soil Cd and Pb, with the correlation coefficients (r) being

308

0.905** (Cd) (Fig. 4a); and 0.931** (Pb) in upland rice cultivars (Fig. 5a) and 0.732**(Cd) (Fig.

309

4b); and 0.847** (Pb) in paddy rice cultivars (Fig. 5b).

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Correlation analysis showed that DTPA-extractable Cd was significantly correlated with

311

soil pH (r: -0.770; P ≤0.05); Eh (r: 0.615; P ≤0.05); CEC (r: -0.937; P ≤0.05); organic matter (r: -

312

0.560; P ≤0.05) and DTPA-extractable Pb was significantly correlated with soil pH (r: -0.839; P

313

≤0.05); Eh (r: 0.594; P ≤0.05); CEC (r: -0.913; P ≤0.05); organic matter (r: -0.569; P ≤0.05) in

314

upland conditions (Table S5). There was more significant correlation of DTPA-extractable Cd

315

with soil pH (r: -0.820; P ≤0.05); Eh (r: 0.623; P ≤0.05); CEC (r: -0.981; P ≤0.05); organic

316

matter (r: -0.706; P ≤0.05) and DTPA-extractable Pb was significantly correlated with soil pH (r:

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-0.829; P ≤0.05); Eh (r: 0.597; P ≤0.05); CEC (r: -0.976; P ≤0.05); organic matter (r: -0.790; P

318

≤0.05) in paddy conditions (Table S5).

319

3.7. Bio-images of elemental distribution in upland and paddy rice root

320

The distribution profile of Cd, Pb, Fe, Zn, Mn, Ca, and Mg of the root sections of upland and

321

paddy rice cultivar made from LA-ICPMS (Laser ablation + ICPMS) determinations of the root

322

sections of upland (Fig. 6a) and paddy rice (Fig. 6b). In upland and paddy rice root, Cd and Pb

323

was concentrated in the center over the root section of control treatment (Fig. 6ab), showing that

324

Cd and Pb absorbed from the soil moved quickly from the epidermis to the stele of the root at

325

higher Cd and Pb concentration. The concentration of Cd and Pb decreased with high lime and

326

dolomite application, due to less DTPA-extractable Cd and Pb, suggesting that when the Cd and

327

Pb contents in the root is low, Cd and Pb retained in the cortex and the cell wall, instead of being

328

moved to the stele. By comparing dolomite and lime treatment, more Cd and Pb was retained in

329

the cortex in lime treatment, but in dolomite treatment more Cd and Pb was retained in cell wall

330

as compared to control and lime treatment. Fe, Zn, Mn, Ca, and Mg were concentrated in both

331

stele and cortex of the upland rice root (Fig. 6a). Fe, Zn, Mn, Ca, and Mg were concentrated in

332

both stele and cortex of the paddy rice root tissue but Mg was low (Fig. 6b). With soil applied

333

lime and dolomite, Fe, Zn, and Mn decreased but Ca and Mg increased in both stele and cortex

334

of the upland rice root, but in paddy rice, there was less displacement of Fe, Zn, and Mn but Ca

335

and Mg increased in both stele and cortex of the paddy rice root. Images showed that root metals

336

intensity was high in upland rice cultivars but it was low in paddy rice cultivars (Fig. 6ab).

337

4. Discussion

338

4.1. Effects of soil moisture on CH4 and N2O emission

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CH4 and N2O production is highly dependent on soil moisture. In this study, 90% reduction in

340

CH4 emission was observed in upland soil as compared to paddy soil. Our results were in

341

accordance with the previous studies, stated that an increase in soil moisture promotes CH4

342

emissions (Hou et al., 2000; Sitaula et al., 1995). Increase in soil moisture causes inhibition of

343

oxygen (O2) exchange and anaerobic soil respiration that inhibit the activities of methanotrophs,

344

and these conditions result in CH4 emission instead of uptake (Adamsen and King, 1993;

345

Shaaban et al., 2015a). In our study, CH4 emission in paddy rice was caused by anaerobic

346

conditions because of increase in methanogens activities by increasing soil moisture and

347

anaerobic conditions. While methanotrophs activity increased with decreasing soil moisture

348

contents (Luo et al., 2013). We assumed that high soil moisture content created anaerobic

349

conditions which accelerated methanogens and inhibit methanotrophs activities and resulted in

350

high CH4 emission in paddy rice. High soil moisture contents also facilitate the decomposition

351

and solubilization of soil organic matter so, the high soil moisture contents act as a stimulator for

352

methanogens to produce CH4 and the low soil moisture content and lime and dolomite

353

application reduced CH4 emission in acidic soil.

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Reduction in soil moisture stimulate N2O producer’s activity and increases N2O emission

355

(Butterbach-Bahl and Papen, 2002). There was 50% decrease in N2O emission in paddy soil

356

(control treatment) as compared to upland soil. Previous studies showed that N2O emission

357

increased by 135% in controlled irrigation (TI 30%) as compared to traditional irrigation (TI

358

100%) (Bonam and Ludden, 1987). Alternate wetting and drying conditions caused by

359

precipitation increase N2O emission through nitrification and denitrification process (Booij et al.,

360

1994). Surface standing water depth (SSWD) play an important role in N2O emission at the time

361

of fertilizer application. A study from north-western Finland, stated that N2O emission was low

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at 15 cm SSWD as compared to 4 cm SSWD showing high N2O emission (Zaman et al., 2008).

363

Similar results reported in a fresh marsh, a higher water table position (+2 - +14 cm) decreased

364

N2O emission as compared to the lower water table (-11 - 0cm) (Galbally et al., 2010). So, the

365

high surface standing water could restrict oxygen, therefore, support the formation of molecular

366

nitrogen (N2) instead of N2O but the lower or no surface standing water absorbed less N2O or

367

even quickly released into the atmosphere (Signor et al., 2013). Hence, N2O emission might be

368

related to the fertilizer application and surface standing water depth rather than the other factors.

369

4.2. Effects of lime and dolomite addition on CH4 and N2O emission

370

Lime and dolomite application significantly reduced CH4 emission in both upland and paddy rice.

371

There was a considerable reduction in CH4 emission in upland rice as compared to paddy

372

conditions. CH4 emission was reduced by 33-45% in both lime and dolomite treatments and our

373

results were similar to previous studies showing that CH4 emission decreased with lime (Brallier

374

et al., 1996; Hutsch et al., 1994) and dolomite (Shaaban et al., 2015a) because the increased soil

375

pH acting as a stimulator for methanotrophs. Borken and Brumme, (1997) stated that lime

376

application in acidic forest soils significantly increased CH4 oxidation and soil uptake by

377

increasing soil pH. Lime application decreased CH4 emission by increasing soil CH4 uptake and

378

decreased CH4 emission in an acidic soil in western Puerto Rico by enhancing methanotrophic

379

activities (Mosier et al., 1998). Bolan et al., (2011) reported that lime application in acidic soils

380

increased uptake of soil CH4. Some contradictory effects of lime application on CH4 oxidation

381

and uptake have also been reported. Page et al., (2009) explained that lime application in acidic

382

soils increased methanogens which resulted in more CH4 emission. The contradictory effects of

383

lime and soil pH on CH4 emission and uptake in the acidic soils associated with the abundance

384

and activities of methanogens and methanotrophs, substrate availability and alteration of

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microbial communities (Benstead and King, 2001; Lalande et al., 2009). Soil pH significantly

386

impacts the activities of methanogens and methanotrophs that control CH4 emission (Lalande et

387

al., 2009). Tate et al., (2007) resulted that CH4 is produced through methanogens and oxidized by

388

methanotrophs which are sensitive to soil pH. In the present study, CH4 emission decreased with

389

lime and dolomite application at a high level of soil pH indicating that the methanotrophs were

390

highly sensitive to soil pH and their activities increased with an increase in soil pH. In addition,

391

Conrad, (1996) stated that CH4-monooxygenase is a key enzyme of CH4 oxidation and is active

392

at high pH as compared to low soil pH. So, the lime and dolomite addition may promote the

393

activities of methanotrophs and CH4-monooxygenase enzyme which increased the oxidation of

394

CH4, and consequently, CH4 emission decreased at higher levels of soil pH.

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Lime and dolomite application significantly reduced N2O emission in both upland and

396

paddy rice. There was 37-52% reduction in N2O emission occurred with both lime and dolomite

397

application and our results were similar to previous studies showing that N2O emissions

398

decreased with dolomite (Shaaban et al., 2014) and lime application (Kato et al., 2011; Mkhabela

399

et al., 2006; Zaman and Nguyen, 2010). Lime application decreased N2O emission by increasing

400

soil N2 and various pastoral soils of New Zealand (Bender and Conrad, 1992; Bonin et al., 1989;

401

Zaman et al., 2007) stated the same results. Similarly, a 2-years field experiment of lime

402

application showed that the average daily emission was 0.96 mg Nm-1 day-1 in control treatment

403

as compared to limed treatment (0.88 mg Nm-1 day-1) (Kato et al., 2011). Soil pH plays a vital

404

role in soil enzymatic activities associated with the reduction of N2O to N2 (Weslien et al., 2009).

405

The N2O-reductase enzyme (NOR) is considered as the primary factor responsible for the

406

reduction of N2O to N2 and is very sensitive to low soil pH (Li et al., 2016). A slight increase in

407

soil pH enhanced the activity of NOR enzyme and decreased N2O emissions (Liu et al., 2010).

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Therefore, our results suggested that a high reduction in N2O emissions through lime and

409

dolomite application was through promoting NOR enzyme activity with increasing soil pH. The

410

previous study showed that an increase in soil pH also influences nitrification and denitrification

411

rates and NH4+-N oxidation which are responsible for N2O emission (Thangarajan et al., 2013).

412

The present study shows that application of lime and dolomite increased the concentration of

413

NO3--N and NH4+-N in the soil as compared to control treatment. Increased soil NO3--N

414

concentration decreased soil N2O emission as compared to control treatment. Similar results

415

were reported in past studies stated that higher soil NO3--N concentration and lower NH4+-N

416

decreased soil N2O emissions (Qu et al., 2014). Moreover, higher production of N2O was

417

observed during denitrification as compared to the nitrification process (Ellis et al., 1998; Feng et

418

al., 2003). Therefore, our results suggested that application of lime and dolomite in acidic soils

419

increased soil pH and decreased N2O emission and cumulative N2O in both upland and paddy

420

rice soil.

421

4.3. Soil liming effects on DTPA-extractable Cd, Pb, and their accumulation in rice

422

Liming neutralize H+ ions and reduced soil extractable Cd (Ardestani and Van Gestel, 2013) and

423

cation exchange capacity (CEC) of the soil plays an essential role in the retention of heavy

424

metals in the soils and liming provides a large number of cations (Ca2+, Mg2+) and large specific

425

surface area for the other element’s attachment (Lee et al., 2009; Lombi et al., 2002). The soil

426

applied lime and dolomite reduced 37-80% DTPA-extractable Cd, and DTPA-extractable Pb

427

decreased by 25-53% and our results were supported by the previous studies (Hong et al., 2007;

428

Khaokaew et al., 2011); stated that soil-liming increased soil metals ions adsorption capacity.

429

The Ca2+ and Mg2+ may compete with Cd and Pb on the rice root surface and increased negative

430

charges which could lead to Cd and Pb sorption and precipitation (Liu et al., 2016). The

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formation of carbonates and hydro-oxides, resulting in a significant reduction in the

432

exchangeable fractions in the contaminated soils (Liu et al., 2007; Mcgrath et al., 1997). Our

433

study showed that high soil pH due to lime and dolomite application reduced DPTA-extractable

434

Cd and Pb from acidic soils. So, the lime and dolomite addition inhibited the translocation of Cd

435

and Pb from soil to the roots, and ultimately limited amounts were translocated to the brown rice.

436

Acidic soil conditions play a crucial role in the accumulation of Cd and Pb in plants (Guo et

437

al., 2018; Yu et al., 2016; Zhao et al., 2015). Our study showed that the soil applied dolomite

438

reduced 47-88% grain Cd and 31-86% grain Cd was reduced by lime application and 58-91%

439

grain Pb was reduced by dolomite application while soil applied lime reduces 32-71% grain Pb.

440

Many experiments showed that liming is quite effective for increasing soil pH and to minimize

441

Cd and Pb accumulation in rice grain (Kim et al., 2016; Zeng et al., 2011). In our experiment, Cd

442

and Pb concentrations were high in roots and gradually decreased from roots to the stem and

443

leaves, and least concentration of both metals was found in the brown rice of both upland and

444

paddy rice cultivars. Our results were supported by earlier research, stated that some cultivars

445

stored a high amount of heavy metals in roots, but transport very little to the above-ground parts,

446

while some rice cultivars accumulate more in the shoots (Deng et al., 2004; Liu et al., 2016).

447

Dolomite treatment results of our experiment showed significant differences in Cd and Pb

448

accumulation in upland and paddy rice cultivars which may be due to increasing competition

449

between Cd, Pb and Ca2+ and Mg2+. Several studies showed that liming increases soil Ca2+ and

450

Mg2+ which may compete with Cd and Pb on the root surface (Kurtyka et al., 2008); and inside

451

the plant and ultimately reducing Cd and Pb accumulation in rice (Hong et al., 2007; Tyler and

452

Olsson, 2001). The above results demonstrated that high soil pH due to lime and dolomite

453

addition played a significant role in the reduction of DTPA-extractable Cd and Pb in acidic soil

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and their accumulation in both upland rice cultivars; Hanyou737>Huyou2 and paddy rice

455

cultivars; Yixiang2292>Taigeng8.

456

4.4. Soil liming effects on mineral nutrients distribution in upland and paddy rice root

457

Mineral nutrients in plants depend on the nature and the organ of the plant and environment.

458

Distribution of Cd, Pb and other elements (Fe, Zn, Mn, Ni, Ca, and Mg) in upland and paddy rice

459

root showed that both elements were concentrated in the stele but the application of dolomite and

460

lime change the distribution pattern and less Cd and Pb was found in the stele of dolomite

461

treatment as compared to lime treatment and control treatment (Fig 5ab) and our results were

462

supported by studies (Bolan et al., 2003; Kim et al., 2002; Sharpley, 1991). Application of

463

dolomite and lime decreased Fe and Zn concentration in rice plant but there was no effect on Fe

464

and Zn distribution and both elements were more concentrated in stele as compared to control

465

treatment (Fig 5ab) and Our results were in accordance with previous studies (Fang and Wong,

466

1999; Franzen and Richardson, 2000; Oste et al., 1994). Ca and Mg was equally distributed in

467

stele and cortex of root tissue. In lime treatment there was high Ca concentration as compared to

468

dolomite treatment and Mg was high in dolomite treatment as compared to lime treatment both

469

in upland and paddy rice root (Fig 5ab) and our results were supported by Mason et al., (1994).

470

Mn was widely distributed inside stele and cortex in control treatment but its intensity decreased

471

with lime addition and it was least in dolomite treatment. Mn was also uniformly distributed

472

within the stele and cortex but lime addition changed its distribution pattern and dolomite

473

addition reduced its intensity both in stele and cortex of the root cells in upland and paddy rice

474

roots (Fig 5ab) and our results were in accordance with Tyler and Olsson, (2001). There was a

475

negative correlation of Cu and Ca in all parts of rice plants, and in case of dolomite application,

476

Cu decreased with increasing Mg in both upland and paddy rice roots showed a negative

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correlation as stated in previous studies Tyler and Olsson, (2001). Nickle showed a negative

478

correlation with Ca and Mg in the roots of upland and paddy rice cultivars (Brallier et al., 1996;

479

Fang and Wong, 1999). Our results showed that lime and dolomite reduced Cd and Pb uptake,

480

distribution and accumulation in rice plant with lime and dolomite application. So, the

481

recommended amount of fertilizers along with dolomite application could be the best strategy for

482

growing upland rice in heavy metals contaminated acidic soils.

483

5. Conclusions

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1.

Upland rice reduces 90% of soil CH4 emission as compared to paddy soil.

485

2.

N2O emission decreased by 44% and 52% with dolomite, and with the lime application it

486 487

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was reduced by 37% and 44% in both upland and paddy soil respectively. 3.

DTPA-extractable soil Cd was reduced between 37-53% and 43-80% with dolomite and

16-37% and 24-72% of Cd with lime application in upland and paddy conditions. The soil

489

applied dolomite reduces DTPA-Pb by 33-41% and 25-53% and 19-29% and 15-38% decrease

490

with the soil applied lime in upland and paddy conditions. 4.

Cd accumulation in rice grain decreased by 47-88% and 62-79% with dolomite and 31-86%

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and 45-52% reduction by the lime application in upland and paddy rice. Rice grain Pb reduced

493

by 58-91% and 66-78% with dolomite application and 32-71% and 44-71% with the soil applied

494

lime in upland and paddy rice, respectively.

495

5.

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Bio-images of elemental distribution developed through LA-ICPMS analysis showed that

496

the soil applied lime and dolomite influenced the distribution of Cd and Pb in upland and paddy

497

rice roots.

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498

6.

According to our study, Huyou2, Taigeng8 and Yixiang2292 are the best rice cultivars

for Cd and Pb co-contaminated acidic soil by applying 3 g of dolomite along with the

500

recommended amount of fertilizers. Further studies are required to investigate long-term

501

manipulation of soil properties effects on CH4 and N2O emission and Cd, Pb uptake and

502

accumulation in upland rice under field conditions.

503

Acknowledgements

504

The authors thank Huang Bifei for technical assistance with ICP-MS analysis, Lu Rong Ye, Li

505

Honghong, Guo Jing Xia, Hai Long Li, and Zhou Cui for their experimental cooperation.

506

Additional information and Declarations

507

Funding

508

This study was funded by the National Natural Science Foundation of China (grant no.

509

U1305232).

510

Author Contributions

511

The field experiment was designed and performed by G. Wang and M.A.K. M.A.K. performed

512

the chemical analysis and other laboratory work. The data analysis was carried out by M.A.K.

513

with the assistance of M.W.K.T. and examined by G. Wang. The manuscript was prepared by

514

M.A.K with the assistance of other authors and was revised by G. Wang.

515

Declaration of Interests:

516

The authors declare that there are no competing financial interests.

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References

519

Adamsen, A.P.S., King, G.M., 1993. Methane consumption in temperate and subarctic forest

520

soils: Rates, vertical zonation, and responses to water and nitrogen. Appl. Environ.

521

Microbiol. 59, 485–490.

RI PT

518

Ardestani, M.M., Van Gestel, C.A.M., 2013. Using a toxicokinetics approach to explain the

523

effect of soil pH on cadmium bioavailability to Folsomia candida. Environ. Pollut. 180,

524

122–130. https://doi.org/10.1016/j.envpol.2013.05.024

M AN U

SC

522

525

Athar, M., James, B., Hui, Y., Saqib, A., Hong, H., Jayasuriya, P., Guo, W., 2019. Uptake,

526

translocation, and accumulation of Cd and its interaction with mineral nutrients (Fe, Zn, Ni,

527

Ca,

528

https://doi.org/10.1016/j.chemosphere.2018.10.077

Mg)

in

upland

rice.

Chemosphere

215,

916–924.

Aulakh, M.S., Wassmann, R., Rennenberg, H., 2001. Methane emissions from rice fields-

530

quantification, mechanisms, role of management, and mitigation options. Adv. Agron. 70,

531

193–260. https://doi.org/10.1016/S0065-2113(01)70006-5

EP

TE D

529

Zaw, A., Sudo, S., Inubushi, K., Mano, M., Yamamoto, A., Ono, K., Osawa, T., Hayashida, S.,

533

Patra, P.K., Terao, Y., Elayakumar, P., Vanitha, K., Umamageswari, C., Jothimani, P., Ravi,

534

V., 2018. Methane and nitrous oxide emissions from conventional and modi fi ed rice

535

cultivation

536

https://doi.org/10.1016/j.agee.2017.10.014

537 538

AC C

532

systems

in

South

India.

Agric.

Ecosyst.

Environ.

252,

148–158.

Bender, M., Conrad, R., 1992. Kinetics of CH4 oxidation in oxic soils exposed to ambient air or high

CH4

mixing

ratios.

FEMS

Microbiol.

Ecol.

101,

261–270.

ACCEPTED MANUSCRIPT

540 541

https://doi.org/10.1016/0168-6496(92)90043-S Benstead, J., King, G.M., 2001. The effect of soil acidification on atmospheric methane uptake by a Maine forest soil. FEMS Microbiol. Ecol. 34, 207–212.

RI PT

539

Bolan, N.S., Adriano, D.C., Kunhikrishnan, A., James, T., McDowell, R., Senesi, N., 2011.

543

Dissolved organic matter. biogeochemistry, dynamics, and environmental significance in

544

soils., Advances in Agronomy. https://doi.org/10.1016/B978-0-12-385531-2.00001-3

SC

542

Bolan, N.S., Adriano, D.C., Mani, P.A., Duraisamy, A., 2003. Immobilization and

546

phytoavailability of cadmium in variable charge soils. II. Effect of lime addition. Plant Soil

547

251, 187–198. https://doi.org/10.1023/A:1023037706905

M AN U

545

Bonam, D., Ludden, P.W., 1987. Purification and characterization of carbon monoxide

549

dehydrogenase, a nickel, zinc, iron-sulfur protein, from Rhodospirillum rubrum. J. Biol.

550

Chem. 262, 2980–2987.

TE D

548

Bonin, P., Gilewicz, M., Bertrand, J.C., 1989. Effects of oxygen on each step of denitrification

552

on Pseudomonas nautica. Can. J. Microbiol. 35, 1061–1064. https://doi.org/10.1139/m89-

553

177

Booij, K., Sundby, B., Helder, W., 1994. Measuring the flux of oxygen to a muddy sediment

AC C

554

EP

551

555

with

556

https://doi.org/10.1016/0077-7579(94)90023-X

557

a

cylindrical

microcosm.

Netherlands

J.

Sea

Res.

32,

1–11.

Borken, W., Brumme, R., 1997. Liming practice in temperate forest ecosystems and the effects

558

on

CO2,

N2O,

and

CH4

fluxes.

Soil

559

https://doi.org/10.1111/j.1475-2743.1997.tb00596.x

Use

Manag.

13,

251–257.

ACCEPTED MANUSCRIPT

Brallier, S., Harrison, R.B., Henry, C.L., Dongsen, X., 1996. Liming effects on availability of Cd,

561

Cu, Ni and Zn in a soil amended with sewage sludge 16 years previously. Water. Air. Soil

562

Pollut. 86, 195–206. https://doi.org/10.1007/BF00279156

RI PT

560

Butterbach-Bahl K. & Papen H., 2002. Four years continuous record of CH4 -exchange between

564

the atmosphere and untreated and limed soil of a N-saturated spruce and beech forest

565

ecosystem in Germany. Plant Soil 240, 77–78.

566

SC

563

Conrad, R., 1996. Soil microorganisms as controllers of atmospheric trace gases (H2, CO, CH4, OCS,

568

https://doi.org/https://doi.org/10.1007/978-3-642-61096-7_11

570

571 572

and

NO).

Microbiol.

Rev.

60,

609–40.

Davidson, E.A., 1993a. Soil water content and the ratio of nitrous oxide to nitric oxide emitted from soil. Soil Sci.

Davidson, E.A., 1993b. Soil water content and the ratio emitted from soil. Biogeochem. Glob. Chang. 369–370.

TE D

569

N2O,

M AN U

567

Deng, H., Ye, Z.H., Wong, M.H., 2004. Accumulation of lead, zinc, copper and cadmium by 12

574

wetland plant species thriving in metal-contaminated sites in China. Environ. Pollut. 132,

575

29–40. https://doi.org/10.1016/j.envpol.2004.03.030

AC C

EP

573

576

Ellis, S., Howe, M.T., Goulding, K.W.T., Mugglestone, M.A., Dendooven, L., 1998. Carbon and

577

nitrogen dynamics in a grassland soil with varying pH: Effect of pH on the denitrification

578

potential and dynamics of the reduction enzymes. Soil Biol. Biochem. 30, 359–367.

579

https://doi.org/10.1016/S0038-0717(97)00122-3

580

Fang, M., Wong, J.W.C., 1999. Effects of lime amendment on availability of heavy metals and

ACCEPTED MANUSCRIPT

581

maturation in sewage sludge composting. Environ. Pollut. 106, 83–89. Feng, K., Yan, F., Hütsch, B.W., Schubert, S., 2003. Nitrous oxide emission as affected by

583

liming an acidic mineral soil used for arable agriculture. Nutr. Cycl. Agroecosystems 67,

584

283–292. https://doi.org/10.1023/B:FRES.0000003664.51048.0e

Franzen, D.W., Richardson, J.L., 2000. Soil factors affecting iron chlorosis of soybean in the red

586

river

valley

of

North

Dakota

and

587

https://doi.org/10.1080/01904160009381998

Minnesota.

J.

Plant

Nutr.

23,

67–78.

SC

585

RI PT

582

Luo, G. J., Kiese, R., Wolf, B., and Butterbach-Bahl, K., 2013. Effects of soil temperature and

589

moisture on methane uptake and nitrous oxide emissions across three different ecosystem

590

types. Biogeosciences 3205–3219. https://doi.org/10.5194/bg-10-3205-2013

M AN U

588

Galbally, I.E., Meyer, M.C.P., Wang, Y.P., Smith, C.J., Weeks, I.A., 2010. Nitrous oxide

592

emissions from a legume pasture and the influences of liming and urine addition. Agric.

593

Ecosyst. Environ. 136, 262–272. https://doi.org/10.1016/j.agee.2009.10.013

TE D

591

Guo, J., Li, Y., Hu, C., Zhou, S., Xu, H., Zhang, Q., Wang, G., 2018. Ca-containing amendments

595

to reduce the absorption and translocation of Pb in rice plants. Sci. Total Environ. 637–638,

596

971–979. https://doi.org/10.1016/j.scitotenv.2018.05.100

AC C

EP

594

597

Hong, C.O., Lee, D.K., Chung, D.Y., Kim, P.J., 2007. Liming effects on cadmium stabilization

598

in upland soil affected by gold mining activity. Arch. Environ. Contam. Toxicol. 52, 496–

599

502. https://doi.org/10.1007/s00244-006-0097-0

600

Hou, A.X., Chen, G.X., Wang, Z.P., Cleemput, O. Van, Patrick, W.H., 2000. Methane and

601

nitrous oxide emissions from a rice field in relation to soil redox and microbiological

ACCEPTED MANUSCRIPT

603

processes. Soil Sci. Soc. Am. Journal. 2186, 2180–2186. Hutsch, B., Webster, C., Powlson, D., 1994. Methane oxidation in soil as affected by land use,

604

soil

pH

and

N

fertilization.

Soil

605

https://doi.org/10.1016/0038-0717(94)90313-1

Biol.

Biochem.

26,

1613–1622.

RI PT

602

IPCC, 1996. CH4 emission from rice cultivation flooded rice field.

607

Kato, T., Hirota, M., Tang, Y., Wada, E., 2011. Spatial variability of CH4 and N2O fluxes in

608

alpine ecosystems on the Qinghai-Tibetan Plateau. Atmos. Environ. 45, 5632–5639.

609

https://doi.org/10.1016/j.atmosenv.2011.03.010

M AN U

SC

606

610

Khaokaew, S., Chaney, R.L., Landrot, G., Ginder-Vogel, M., Sparks, D.L., 2011. Speciation and

611

release kinetics of cadmium in an alkaline paddy soil under various flooding periods and

612

draining

613

https://doi.org/10.1021/es103971y

Environ.

Sci.

Technol.

45,

4249–4255.

TE D

conditions.

Kim, S.C., Kim, H.S., Seo, B.H., Owens, G., Kim, K.R., 2016. Phytoavailability control based

615

management for paddy soil contaminated with Cd and Pb: Implications for safer rice

616

production. Geoderma 270, 83–88. https://doi.org/10.1016/j.geoderma.2015.11.031

EP

614

Kim, Y., Yang, Y., Lee, Y., 2002. Pb and Cd uptake in rice roots. Physiol. Plant. 116, 368–372.

618

Kirchmann, H., Witter, E., 1989. Ammonia volatilization during aerobic and anaerobic manure

619

620 621

622

AC C

617

decomposition. Plant Soil 115, 35–41. https://doi.org/10.1007/BF02220692 Komarek, M., Ettler, V., Chrastny, V., Mihaljevic, M., 2008. Lead isotopes in environmental sciences: A review. Environ. Int. 34, 562–577. https://doi.org/10.1016/j.envint.2007.10.005 Kurtyka, R., Małkowski, E., Kita, A., Karcz, W., 2008. Effect of calcium and cadmium on

ACCEPTED MANUSCRIPT

623

growth and accumulation of cadmium, calcium, potassium and sodium in maize seedlings.

624

Polish J. Environ. Stud. 17. Lalande, R., Gagnon, B., Royer, I., 2009. Impact of natural or industrial liming materials on soil

626

properties

and

microbial

activity.

627

https://doi.org/10.4141/CJSS08015

Can.

J.

RI PT

625

Soil

Sci.

89,

209–222.

Lee, S.H., Lee, J.S., Jeong Choi, Y., Kim, J.G., 2009. In situ stabilization of cadmium-, lead-,

629

and zinc-contaminated soil using various amendments. Chemosphere 77, 1069–1075.

630

https://doi.org/10.1016/j.chemosphere.2009.08.056

632

M AN U

631

SC

628

Li, H., Liu, Y., Chen, Y., Wang, S., Wang, M., Xie, T., Wang, G., 2016. Biochar amendment immobilizes lead in rice paddy soils and reduces its phytoavailability. Sci. Rep. 6, 31616. Liu, B., Morkved, P.T., Frostegard, A., Bakken, L.R., 2010. Denitrification gene pools,

634

transcription and kinetics of NO, N2O and N2 production as affected by soil pH. FEMS

635

Microbiol. Ecol. 72, 407–417. https://doi.org/10.1111/j.1574-6941.2010.00856.x

TE D

633

Liu, C., Gong, X., Chen, C., Yang, J., Xu, S., 2016. The effect of iron plaque on lead

637

translocation in soil-Carex cinerascens kukenth. system. Int. J. Phytoremediation 18, 1–9.

638

https://doi.org/10.1080/15226514.2015.1021954

AC C

EP

636

639

Liu, H.J., Zhang, J.L., Zhang, F.S., 2007. Role of iron plaque in Cd uptake by and translocation

640

within rice (Oryza sativa L.) seedlings grown in solution culture. Environ. Exp. Bot. 59,

641

314–320. https://doi.org/10.1016/j.envexpbot.2006.04.001

642

Lombi, E., Zhao, F.J., Zhang, G., Sun, B., Fitz, W., Zhang, H., McGrath, S.P., 2002. In situ

643

fixation of metals in soils using bauxite residue: Chemical assessment. Environ. Pollut. 118,

ACCEPTED MANUSCRIPT

644

435–443. https://doi.org/10.1016/S0269-7491(01)00294-9 Mason, M. G., Porter, W. M., and Cox,W.J., 1994. Effect of an acidifying nitrogen fertiliser and

646

lime on soil pH and wheat yields. 2. Plant response. Aust. J. Exp. Agric. 34.

647

https://doi.org/10.1071/EA9940247

RI PT

645

Mcgrath, S.P., Shen, Z.G., Zhao, F.J., 1997. Heavy metal uptake and chemical changes in the

649

rhizosphere of Thlaspi caerulescens and Thlaspi ochroleucum grown in contaminated soils.

650

Plant Soil 188, 153–159.

SC

648

Mitra, S., Wassmann, R., Jain, M.C., Pathak, H., 2002. Properties of rice soils affecting methane

652

production potentials : 2 . Differences in topsoil and subsoil. Nutr. Cycl. Agroecosystems 64,

653

183–191.

M AN U

651

Mkhabela, M.S., Gordon, R., Burton, D., Madani, A., Hart, W., 2006. Effect of lime,

655

dicyandiamide and soil water content on ammonia and nitrous oxide emissions following

656

application of liquid hog manure to a marshland soil. Plant Soil 284, 351–361.

657

https://doi.org/10.1007/s11104-006-0056-6

TE D

654

Mosier, A.R., Delgado, J.A., Keller, M., 1998. Methane and nitrous oxide fluxes in an acid

659

oxisol in western Puerto Rico: Effects of tillage, liming and fertilization. Soil Biol. Biochem.

660

30, 2087–2098. https://doi.org/10.1016/S0038-0717(98)00085-6

AC C

EP

658

661

Oste, A. L., Dolfing, J., Wei-Chun, M., and Lexmond, M.T., 2001. Effect of beringite on

662

cadmium and zinc uptake by plants and earthworms: More than a liming effect? Environ.

663

Toxicol. Chem. 20, 1339–1345. https://doi.org/10.1897/1551-5028(2001)020<1339

664

Page, K.L., Allen, D.E., Dalal, R.C., Slattery, W., 2009. Processes and magnitude of CO2, CH4,

ACCEPTED MANUSCRIPT

665

and N2O fluxes from liming of Australian acidic soils: a review. Aust. J. Soil Res. 47, 747.

666

https://doi.org/10.1071/SR09057 Patra, B.N., Mohanty, S.K., 1994. Effect of nutrients and liming on changes in pH, redox

668

potential, and uptake of iron and manganese by wetland rice in iron-toxic soil. Biol. Fertil.

669

Soils Bioenergy 3, 285–288.

RI PT

667

Qu, Z., Wang, J., Almoy, T., Bakken, L.R., 2014. Excessive use of nitrogen in Chinese

671

agriculture results in high N2O/(N2O+N2) product ratio of denitrification, primarily due to

672

acidification

673

https://doi.org/10.1111/gcb.12461

the

soils.

Glob.

Chang.

Biol.

20,

1685–1698.

M AN U

of

SC

670

Saari, A., Rinnan, R., Martikainen, P.J., 2004. Methane oxidation in boreal forest soils: Kinetics

675

and sensitivity to pH and ammonium. Soil Biol. Biochem. 36, 1037–1046.

676

https://doi.org/10.1016/j.soilbio.2004.01.018

TE D

674

677

Sass, R.L., 1997. CH4 emissions from rice agriculture, in: Agriculture. pp. 399–417.

678

Shaaban, M., Peng, Q., Hu, R., Wu, Y., Lin, S., 2015a. Dolomite application to acidic soils : a promising

option

for

mitigating

680

https://doi.org/10.1007/s11356-015-5238-4

N 2O

emissions.

Environ.

Sci.

Pollut.

Res.

AC C

EP

679

681

Shaaban, M., Wu, Y., Peng, Q., Lin, S., Mo, Y., 2015b. Effects of dicyandiamide and dolomite

682

application on N2O emission from an acidic soil. Environ. Sci. Pollut. Res.

683

https://doi.org/10.1007/s11356-015-5863-y

684 685

Shaaban, M., Peng, Q., Lin, S., Wu, Y., Zhao, J., Ronggui, H., 2014. Nitrous oxide emission from two acidic soils as affected by dolomite application. Soil Res. 52, 841–848.

ACCEPTED MANUSCRIPT

Sharma, R.K., Agrawal, M., Marshall, F.M., 2008. Heavy metal (Cu, Zn, Cd and Pb)

687

contamination of vegetables in urban India: A case study in Varanasi. Environ. Pollut. 154,

688

254–263. https://doi.org/10.1016/j.envpol.2007.10.010

691 692

693

Anal. 22, 827–841. https://doi.org/10.1080/00103629109368457

Signor, D., Eduardo, C., Cerri, P., 2013. Nitrous oxide emissions in agricultural soils: a review. Pesqui. Agropecu. Trop. Goiania 2013, 322–338.

SC

690

Sharpley, A.N., 1991. Effect of soil pH on cation and anion solubility. Commun. Soil Sci. Plant

Sitaula, B.K., Bakken, L.R., Abrahamsen, G., 1995. CH4 uptake by temperate forest soil: Effect N

input

and

soil

M AN U

689

RI PT

686

694

of

acidification.

695

https://doi.org/10.1016/0038-0717(95)00017-9

Soil

Biol.

Biochem.

27,

871–880.

Smolders, E., Oorts, K., Van Sprang, P., Schoeters, I., Janssen, C.R., McGrath, S.P., McLaughlin,

697

M.J., 2009. Toxicity of trace metals in soil as affected by soil type and aging after

698

contamination: Using calibrated bioavailability models to set ecological soil standards.

699

Environ. Toxicol. Chem. 28, 1633–1642. https://doi.org/10.1897/08-592.1

TE D

696

Tate, K.R., Ross, D.J., Saggar, S., Hedley, C.B., Dando, J., Singh, B.K., Lambie, S.M., 2007.

701

Methane uptake in soils from Pinus radiata plantations, a reverting shrubland and adjacent

702

pastures: Effects of land-use change, and soil texture, water and mineral nitrogen. Soil Biol.

703

Biochem. 39, 1437–1449. https://doi.org/10.1016/j.soilbio.2007.01.005

705

706

AC C

704

EP

700

Teng, Y., Wu, J., Lu, S., Wang, Y., Jiao, X., Song, L., 2014. Soil and soil environmental quality monitoring in China: A review. Environ. Int. https://doi.org/10.1016/j.envint.2014.04.014 Thangarajan, R., Bolan, N.S., Tian, G., Naidu, R., Kunhikrishnan, A., 2013. Role of organic

ACCEPTED MANUSCRIPT

707

amendment application on greenhouse gas emission from soil. Sci. Total Environ. 465, 72–

708

96. https://doi.org/10.1016/j.scitotenv.2013.01.031

711

by soil acidity and liming. Plant Soil 230, 307–321.

Wang, H., Liu, C., Zhang, L., 2002. Water saving agriculture in China: An overview. Adv.

712

Agron.

713

2113(02)75004-9

715

Volume

75,

135–171.

https://doi.org/http://dx.doi.org/10.1016/S0065-

Wang, Y., and Wang, Y., 2003. Quick measurement of CH4, CO2 and N2O emissions from a

M AN U

714

RI PT

710

Tyler, G., and Olsson, T., 2001. Plant uptake of major and minor mineral elements as influenced

SC

709

short-plant ecosystem. Adv. Atmos. Sci. 20, 842–844. https://doi.org/10.1007/BF02915410 Weslien, P., Kasimir Klemedtsson, A., Borjesson, G., Klemedtsson, L., 2009. Strong pH

717

influence on N2O and CH4 fluxes from forested organic soils. Eur. J. Soil Sci. 60, 311–320.

718

https://doi.org/10.1111/j.1365-2389.2009.01123.x

720

Wiechula, D., and Loska K., 2000. Effects of pH and aeration on copper migration in above sediment water. Polish J. Environ. Stud. 9, 433–437.

EP

719

TE D

716

Yang, W.T., Zhou, H., Gu, J.F., Liao, B.H., Peng, P.Q., Zeng, Q.R., 2017. Effects of a combined

722

amendment on Pb, Cd, and As availability and accumulation in rice planted in contaminated

723

paddy

724

https://doi.org/10.1080/15320383.2017.1235132

AC C

721

soil.

Soil

Sediment

Contam.

26,

70–83.

725

Yang, X., Feng, Y., He, Z., Stoffella, P.J., 2005. Molecular mechanisms of heavy metal

726

hyperaccumulation and phytoremediation. J. Trace Elem. Med. Biol. 18, 339–353.

727

https://doi.org/10.1016/j.jtemb.2005.02.007

ACCEPTED MANUSCRIPT

Yang, Y., Chen, J., Huang, Q., Tang, S., Wang, J., Hu, P., Shao, G., 2018. Can liming reduce

729

cadmium (Cd) accumulation in rice (Oryza sativa) in slightly acidic soils? A contradictory

730

dynamic equilibrium between Cd uptake capacity of roots and Cd immobilisation in soils.

731

Chemosphere 193, 547–556. https://doi.org/10.1016/j.chemosphere.2017.11.061

RI PT

728

Yang, Y., Chen, R., Fu, G., Xiong, J., Tao, L., 2016. Phosphate deprivation decreases cadmium

733

(Cd) uptake but enhances sensitivity to Cd by increasing iron (Fe) uptake and inhibiting

734

phytochelatins synthesis in rice (Oryza sativa). Acta Physiol. Plant. 38, 1–13.

735

https://doi.org/10.1007/s11738-015-2055-9

M AN U

SC

732

736

Yu, H.Y., Liu, C., Zhu, J., Li, F., Deng, D.M., Wang, Q., Liu, C., 2016. Cadmium availability in

737

rice paddy fields from a mining area: The effects of soil properties highlighting iron

738

fractions

739

https://doi.org/10.1016/j.envpol.2015.11.021

pH

value.

Environ.

Pollut.

209,

38–45.

TE D

and

Zaman, M., Nguyen, M.L., 2010. Effect of lime or zeolite on N2O and N2 emissions from a

741

pastoral soil treated with urine or nitrate-N fertilizer under field conditions. Agric. Ecosyst.

742

Environ. 136, 254–261. https://doi.org/10.1016/j.agee.2009.12.002

EP

740

Zaman, M., Nguyen, M.L., Matheson, F., Blennerhassett, J.D., Quin, B.F., 2007. Can soil

744

amendments (zeolite or lime) shift the balance between nitrous oxide and dinitrogen

745

emissions from pasture and wetland soils receiving urine or urea-N? Aust. J. Soil Res. 45,

746

543–553. https://doi.org/10.1071/SR07034

AC C

743

747

Zaman, M., Nguyen, M.L., Saggar, S., 2008. N2O and N2 emissions from pasture and wetland

748

soils with and without amendments of nitrate, lime and zeolite under laboratory condition.

749

Aust. J. Soil Res. 46, 526–534. https://doi.org/10.1071/SR07218

ACCEPTED MANUSCRIPT

Zeng, F., Ali, S., Zhang, H., Ouyang, Y., Qiu, B., Wu, F., Zhang, G., 2011. The influence of pH

751

and organic matter content in paddy soil on heavy metal availability and their uptake by rice

752

plants. Environ. Pollut. 159, 84–91. https://doi.org/10.1016/j.envpol.2010.09.019

RI PT

750

Zhao, F.J., Ma, Y., Zhu, Y.G., Tang, Z., McGrath, S.P., 2015. Soil contamination in China:

754

Current status and mitigation strategies. Environ. Sci. Technol. 49, 750–759.

755

https://doi.org/10.1021/es5047099

SC

753

Zou, J., Huang, Y., Jiang, J., Sass, R.L., 2005. A 3-year field measurement of methane and

757

nitrous oxide emissions from rice paddies in China: Effects of water regime, crop residue,

758

and

759

https://doi.org/10.1029/2004GB002401

fertilizer

application.

Global

AC C

EP

TE D

760

M AN U

756

Biogeochem.

Cycles

19,

1–9.

ACCEPTED MANUSCRIPT

Table 1 Changes in soil properties after lime and dolomite application

Paddy conditions (～3 cm above soil surface)

5

Dolomite

Lime

Dolomite

Lime

SOM 20.29±0.47a

Eh (mV) 439±16a

4.73±0.04

1.5

5.44±0.02

47.20±0.82b

20.63±0.58a

---

3

6.47±0.03

57.63±0.81a

21.05±0.35a

1.5

5.38±0.03

45.76±0.70b

3

6.36±0.06

0

(g kg-1)

NO3--N (mg kg-1) 5.60±0.11b

NH4+-N (mg kg-1) 0.32±0.01c

Cumulative mean N2O (µg kg-1) 1132a

Cumulative mean CH4 (µg kg-1) 75a

---

---

---

---

401±13ab

6.82±0.01a

0.89±0.01a

631c

40c

20.66±0.52a

---

---

---

---

---

53.83±0.83a

20.93±0.44a

391±14b

6.63±0.01a

0.62±0.02b

705b

48b

5.06±0.02

38.34±0.40c

20.18±0.13a

135±11a

2.69±0.03c

0.98±0.01b

393a

2284a

1.5

5.81±0.01

44.99±0.70b

20.50±0.30a

---

---

---

---

---

3

6.83±0.12

52.89±0.55a

20.88±0.23a

117±10b

4.97±0.08a

1.82±0.01a

187c

1393c

1.5

5.65±0.01

43.42±0.55b

20.44±0.49a

---

---

---

---

---

3

6.70±0.16

50.20±0.84a

20.69±0.43a

106±12c

4.36±0.07b

1.71±0.02a

220b

1518b

Note: CEC = cation exchange capacity, SOM = soil organic matter. Mean values with different letters are significantly different from each other (p≤0.05) and same letters show no statistical differences.

TE D

4

0

CEC (cmol(+)/kg) 37.46±0.50c

EP

2 3

pH

(g kg-1)

RI PT

(～70% moisture)

Levels

SC

Upland conditions

Treatments

M AN U

Growth conditions

AC C

1

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Table 2 Soil DTPA-extractable Cd after harvest and Cd concentration in different parts of rice plant against dolomite and lime treatments

Dolomite Taigeng8 Lime

Dolomite Hanyou737 Lime

Stem (mg kg-1) 5.17±0.12a

Leaf (mg kg-1) 4.14±0.29a

Brown rice (mg kg-1) 1.48±0.03a

1.5

0.53±0.02c

3.52±0.22c

3.74±0.1b

2.56±0.14b

0.79±0.06c

3.0

0.35±0.01e

1.61±0.13d

2.15±0.07c

1.71±0.31c

0.17±0.00d

1.5

0.70±0.02b

4.62±0.21b

3.91±0.09b

2.69±0.15b

1.04±0.05b

3.0

0.47±0.01d

2.19±0.19c

2.35±0.07c

1.8±0.42c

0.21±0.05d

0

0.58±0.02a

3.68±0.08a

0.42±0.04a

0.17±0.01a

0.29±0.03a

1.5

0.32±0.01c

1.30±0.1d

0.29±0.03b

0.14±0.01b

0.13±0.01c

3.0

0.12±0.02e

0.26±0.07e

0.12±0.03c

0.08±0.01c

0.07±0.01d

1.5

0.43±0.02b

2.30±0.06b

0.29±0.03b

0.15±0.01a

0.19±0.01b

3.0

0.18±0.01d

1.55±0.07c

0.14±0.03c

0.11±0.01c

0.17±0.01b

0

0.74±0.01a

9.3±0.23a

6.45±0.16a

5.97±0.28a

1.92±0.06a

1.5

0.44±0.01cd

5.54±0.28b

4.25±0.10b

3.75±0.22b

0.99±0.07c

3.0

0.36±0.03d

3.31±0.37c

2.21±0.12c

2.48±0.06c

0.21±0.01d

0.59±0.02b

5.94±0.24b

4.44±0.11b

3.94±0.23b

1.28±0.08b

0.49±0.02c

4.38±0.18c

2.47±0.14c

2.61±0.07c

0.24±0.02d

0.53±0.02a

5.27±0.18a

1.19±0.03a

0.37±0.07a

0.5±0.03a

0.31±0.02c

2.12±0.21c

0.63±0.03c

0.22±0.01b

0.15±0.01c

0.10±0.00d

0.90±0.08e

0.44±0.02e

0.15±0.01c

0.09±0.01d

1.5

0.41±0.02b

3.27±0.26b

0.79±0.03b

0.24±0.01b

0.22±0.01b

3.0

0.13±0.01d

1.28±0.04d

0.56±0.03d

0.16±0.01c

0.18±0.01c

1.5 3.0 0

Dolomite

1.5

Lime

AC C

3.0

Yixiang2292

RI PT

Lime

Root (mg kg-1) 6.01±0.09a

SC

Huyou2

0

DTPA-Cd (mg kg-1) 0.80±0.03a

M AN U

Dolomite

Amendment rates (g kg-1)

TE D

Treatments

EP

Rice cultivars

Note: Mean Cd values with different letters are significantly different from each other (p≤0.05) and same letters show no statistical differences.

ACCEPTED MANUSCRIPT

Table 3 Soil DTPA-extractable Pb after harvest and Pb concentration in different parts of rice plant against dolomite and lime treatments

Dolomite Taigeng8 Lime

Dolomite Hanyou737

Stem (mg kg-1)

Leaf (mg kg-1)

Brown rice (mg kg-1)

0

308.62±2.31a

229.9±1.87a

61.43±1.18a

18.7±0.29a

1.87±0.03a

1.5

234.04±1.61c

185.21±2.60c

47.42±1.44b

16.66±0.14a

0.71±0.06c

3.0

187.83±2.10e

135.05±2.78e

30.40±0.19d

10.98±0.31b

0.11±0.00e

1.5

258.21±2.06b

214.45±1.83b

59.15±1.4a

17.85±0.15a

1.26±0.05b

3.0

225.77±1.07d

173.22±2.72d

41.75±0.27c

15.16±0.42a

0.57±0.05d

0

265.58±1.99a

195.45±0.37a

11.78±0.01a

5.95±0.52a

0.52±0.03a

1.5

199.02±0.52c

144.40±1.26c

4.24±0.04c

2.34±0.06b

0.21±0.01c

3.0

132.90±1.13e

84.70±1.21e

1.39±0.01e

0.46±0.05d

0.13±0.01d

1.5

216.22±1.56b

155.77±0.71b

5.87±0.04b

2.55±0.07b

0.28±0.01b

3.0

172.34±2.07d

121.63±2.52d

2.64±0.02d

0.84±0.06c

0.16±0.01d

0

303.96±1.52a

329.15±2.30a

76.05±1.93a

20.69±0.52a

2.21±0.05a

1.5

200.04±1.57c

282.72±2.72c

56.74±0.90c

19.08±0.22a

0.98±0.04c

169.02±0.29e

249.26±1.83e

38.07±0.43e

12.43±0.29c

0.26±0.01e

238.09±1.98b

294.78±2.34b

71.67±1.13b

20.44±0.24a

1.5±0.01b

183.35±0.37d

270.28±2.05d

52.21±0.59d

17.15±0.4b

0.57±0.06d

250.21±1.33a

299.93±1.76a

17.84±0.11a

9.81±0.49a

0.83±0.04a

188.62±0.90c

204.97±2.42d

10.51±0.14c

6.22±0.04b

0.22±0.01c

108.08±1.33e

119.07±2.33e

6.01±0.10e

3.61±0.00d

0.15±0.02d

1.5

221.75±2.03b

278.98±2.32b

13.42±0.18b

7.48±0.04b

0.47±0.03b

3.0

145.26±1.57d

255.25±1.81c

8.45±0.14d

5.10±0.00c

0.22±0.01c

3.0 Lime

1.5 3.0 0

Dolomite

3.0 Lime

AC C

Yixiang-2292

1.5

RI PT

Lime

Root (mg kg-1)

SC

Huyou2

DTPA-Pb (mg kg-1)

M AN U

Dolomite

Amendment rates (g kg-1)

TE D

Treatments

EP

Rice cultivars

Note: Mean Pb values with different letters are significantly different from each other (p≤0.05) and same letters show no statistical differences.

ACCEPTED MANUSCRIPT

SC

RI PT

a

1

EP

TE D

M AN U

Fig. 1. Soil collection area (Nanya village, Jianou county, Nanping city, Fujian province) used for the pot experiment

AC C

2 3

ACCEPTED MANUSCRIPT

0.07 Ck Lime Dolomite

RI PT

0.05

0.04

0.03

SC

-1 -1 CH4-C emission (µg kg h )

0.06

0.02

0.00 15

30

M AN U

0.01

45

60

75

90

Time (Days)

4 1.6

b

0.8

TE D EP

1.2

AC C

-1 -1 CH4-C emission (µg kg h )

1.4

1.0

Ck Lime Dolomite

0.6

0.4

15

5

30

45

60

Time (Days)

75

90

ACCEPTED MANUSCRIPT

6

Fig. 2. CH4 emission from (a) upland and (b) paddy rice soil of control, lime and dolomite

treatment

7

1.0

a

0.4

0.2

0.0 15

30

45

60

EP

TE D

Time (Days)

AC C

9

CK Lime Dolomite

SC

0.6

M AN U

-1 -1 N2O-N emission (µg kg h )

0.8

RI PT

8

75

90

ACCEPTED MANUSCRIPT

0.5

b

CK Lime Dolomite

RI PT

0.3

0.2

0.1

SC

-1 -1 N2O-N emission (µg kg h )

0.4

15

30

60

75

90

Fig. 3. N2O emission from (a) upland and (b) paddy rice soil of control, lime and dolomite

EP

TE D

treatment

AC C

14

45

Time (Days)

10 11 12 13

M AN U

0.0

ACCEPTED MANUSCRIPT

1.80

1.40 1.20 1.00

RI PT

Brown rice Cd (mg kg-1)

1.60

a y = 2.951x - 0.941 r² = 0.905**, n = 15

0.80 0.60 0.40

0.00 0.30

0.40

0.50 0.60 0.70 DTPA-extracable Cd (mg kg-1)

0.40

y = 0.395x + 0.042 r² = 0.732*, n = 15

0.30 0.25 0.20 0.15 0.10 0.05

17 18 19 20 21

0.20 0.30 0.40 0.50 DTPA-extracable Cd (mg kg-1)

0.60

0.90

b

0.70

Fig. 4. DTPA-extractable Cd and Cd accumulation in brown rice in (a) upland and (b) paddy

conditions

AC C

16

0.10

EP

0.00 0.00

TE D

Brown rice Cd (mg kg-1)

0.35

0.80

M AN U

15

SC

0.20

ACCEPTED MANUSCRIPT

a

y = 0.0146x - 2.64 r² = 0.931**, n = 15

2.00 1.50

RI PT

Brown rice Pb (mg kg-1)

2.50

1.00 0.50

180

200

220

240 260 280 300 -1 DTPA-extracable Pb (mg kg )

y = 0.0268x - 1.831 r² = 0.880**, n = 15

2.0 1.5 1.0 0.5 0.0

24 25

250 300 -1 DTPA-extracable Pb (mg kg )

340

b

350

Fig. 5. DTPA-extractable Pb and Pb accumulation in brown rice in (a) upland and (b) paddy

conditions

AC C

23

200

EP

150

TE D

Brown rice Pb (mg kg-1)

2.5

320

M AN U

22

SC

0.00

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

26

Fig. 6a. Elemental bioimages showing distribution of Cd, Pb, Fe, Zn, Ca, Mg, and Mn over the

28

cross sections of upland rice (Hanyou737) roots for control, lime and dolomite

29

treatment

AC C

30

EP

27

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

31

Fig. 6b. Elemental bioimages showing distribution of Cd, Pb, Fe, Zn, Ca, Mg, and Mn over the

33

cross sections of paddy rice (Yixiang2292) roots for control, lime and dolomite

34

treatment

AC C

35

EP

32

ACCEPTED MANUSCRIPT

1

HIGHLIGHTS

2

•

Upland rice reduces 90% of soil CH4 emission as compared to paddy soil.

3

•

N2O emission decreased by 44% and 52% with dolomite, and with lime application it was

5

•

RI PT

reduced by 37% and 44% in both upland and paddy soil, respectively.

4

Cd accumulation in rice grain decreased by 47-88% and 62-79% with dolomite and 31-86% and 45-52% reduction by lime application, and rice grain Pb reduced by 58-91% and 66-78%

7

with dolomite application and 32-71% and 44-71% with soil-applied lime in upland and

8

paddy rice, respectively.

AC C

EP

TE D

M AN U

SC

6