- Email: [email protected]
Life cycle assessment of autochthonous varieties of wheat and artisanal bread production in Galicia, Spain
Journal Pre-proof Life cycle assessment of autochthonous varieties of wheat and artisanal bread production in Galicia, Spain
Iana Câmara Salim, Fernando Almeida-García, Sara GonzálezGarcía, Angeles Romero-Rodríguez, Benigno Ruíz-Nogueiras, Santiago Pereira-Lorenzo, Gumersindo Feijoo, Maria Teresa Moreira PII:
S0048-9697(20)30230-8
DOI:
https://doi.org/10.1016/j.scitotenv.2020.136720
Reference:
STOTEN 136720
To appear in:
Science of the Total Environment
Received date:
8 October 2019
Revised date:
13 January 2020
Accepted date:
14 January 2020
Please cite this article as: I.C. Salim, F. Almeida-García, S. González-García, et al., Life cycle assessment of autochthonous varieties of wheat and artisanal bread production in Galicia, Spain, Science of the Total Environment (2020), https://doi.org/10.1016/ j.scitotenv.2020.136720
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. 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.
© 2020 Published by Elsevier.
Journal Pre-proof Life cycle assessment of autochthonous varieties of wheat and artisanal bread production in Galicia , Spain
Iana Câmara Salim1,a*, Fernando Almeida-García2,4*, Sara González-García1 , Angeles Romero-Rodríguez3, Benigno Ruíz-Nogueiras4, Santiago Pereira-Lorenzo4, Gumersindo
of
Feijoo1 and Maria Teresa Moreira1
(2) Grupo Da Cunha. 15175 Carral. Spain.
-p
Compostela. 15782 Santiago de Compostela. Spain.
ro
(1) CRETUS Institute. Department of Chemical Engineering. Universidade de Santiago de
lP
Compostela. 27002 Lugo. Spain.
re
(3) Department of Analytical Chemistry, Faculty of Sciences Universidade de Santiago de
na
(4) Dept. of Crop Production and Engineering Projects. High Polytechnich School of
a
Jo ur
Engineering. Universidade de Santiago de Compostela. 27002 Lugo. Spain.
Corresponding author
* These authors contributed equally to this work.
Abstract
For millennia, bread and wheat have been one of the most important sources of nutrients in many civilizations. Today, mechanization and evolution in agriculture and food processing have intensified yields and modified the biological and nutritional aspects of multiple crops and foods. The Galician bread is a reference value of food heritage in Spain, which is made 1
Journal Pre-proof from common wheat grain and is a mixture of indigenous Galician wheat and conventional Spanish wheat. In the pursuit of product excellence, it is interesting to identify the environmental profile as support criteria in decision-making, not only to analyse product environmental sustainability, but also as a marketing element to improve consumer awareness. The paper has a twofold perspective to analyse the environmental burdens of wheat
of
cultivation and the bread sector, using life cycle assessment approach: 1) the comparison of
ro
the different types of agricultural systems, i.e. the cultivation of Galician wheat following a
-p
strategy of monoculture and crop rotation, certified Galician seed production and its comparison with conventional wheat cultivation and 2) the environmental profile of Galician
lP
facility and 1 kg of Galician bread.
re
bread. The functional units chosen were 1 kg of wheat grain transported to the milling
na
The results show that wheat cultivation presents the main environmental impacts of bread production, mainly due to the use of agrochemicals and field emissions. The best cultivation
Jo ur
scenario corresponds to a crop rotation system, since chemical fertilisation is not applied. In comparative terms with many staple foods produced in Europe, Galician bread has a low environmental impact. The overall environmental results of bread production draw attention to the dependence of bread and flour manufacturers on the agricultural sector, highlighting the need to share responsibilities across the supply chain. In addition, this study contributes to the stakeholder debate on environmental impacts related to food heritage.
Keywords: crop rotation system, life cycle assessment, food heritage, bread production, wheat cultivation
2
Journal Pre-proof
1. Introduction
Wheat was and remains one of the main staple foods of many civilizations. Different types of genetic diversity crops have been developed for different consumption purposes. About 95% of the world production is common wheat, also called bread wheat (Triticum aestivum) and the remaining 5% is durum wheat (Triticum durum), mainly for the production of pasta
of
and couscous (Taylor, 2017). Milling and baking industries evaluate wheat composition (e.g.,
ro
starch and protein content) and other specifications (e.g., bulk density and shape) to meet
-p
their demand (Mancuso et al., 2019).
re
Currently, there are about 219 million ha of wheat-growing areas in the globe. World
lP
production amounts to 770 million t, of which 5 countries (China, India, Russia, USA and
na
France) account for more than half of the world production (FAOSTAT, 2018). In Europe, total production represents about 150 million tonnes, with Spain representing only 3% of
Jo ur
total European production, concentrated mainly in the autonomous regions of Castilla y León and Andalusia (Calatrava et al., 2018).
In Galicia, wheat cultivation is less representative in quantitative terms (about 0.5% of Spanish production). The grain of native Galician wheat can be classified in the varieties of wheat "Caveeiro" and "Callobre", which is a winter (mainly sown in autumn and harvested in late spring or early summer) and soft wheat that, compared to durum wheat, has more starch and less gluten. Surprisingly, Galician bread is a reference of quality at national level, which is largely attributed to the variety of native wheat that offers a distinct flavour and taste to bread as well as to its differentiated production scheme, such as the use of
3
Journal Pre-proof fermented dough and the requirement of long times of fermentation and baking in stone ovens. In an increasingly industrialised agriculture, the search for more traditional varieties that preserve the genuine organoleptic properties of bread is a growing demand. In this sense, the consumer is not only interested in preserving the food heritage associated with ingredients and artisanal production techniques (Kulak et al., 2015), but also prefers to buy a product of higher quality and taste, accredited as organic or produced according to
of
sustainable production patterns (Ingrao et al., 2018). Beyond product excellence, the
ro
assessment of the environmental profile associated with agricultural activities can provide
-p
information on the strategy for marketing healthier and more sustainable food products.
re
Life cycle assessment (LCA) is an interesting tool to have a broad environmental perspective
lP
of the production chain. The International Standards ISO 14040 and 14044 (ISO14040, 2006; ISO14044, 2006) establish principles and guidelines to perform LCA, using four important
na
steps: goal and scope definition, life cycle inventory assessment (LCI), life cycle impact
Jo ur
assessment (LCIA) and interpretation. LCA is capable of evaluating all the activities involved in the production of the crop and may involve the stages from agrochemical production, agricultural activities, transport, storage, delivery, consumption and end-of-life. The system boundaries vary for each case study, depending on the reliability of the data and the purpose of the study.
There are different LCA studies on wheat cultivation. A number of authors have investigated wheat cultivation for non-food markets, such as for bioenergy systems (De Matos et al., 2015; Gissén et al., 2014; Muñoz et al., 2014; Röder et al., 2015). Others have focused on common wheat varieties (Mancuso et al., 2019) and different management practices, e.g. comparison of different winter wheat cropping systems (Cambria et al., 2016); and the use 4
Journal Pre-proof of crop rotation systems (Wang et al., 2014). There are also references of interest in which wheat crops are compared with other arable crops (Romeiko, 2019; Williams et al., 2010). Inventory data in the different studies have been identified at regional (Noya et al., 2015; Tabatabaie et al., 2016), country (Liang et al., 2018) and continental (Achten and Van Acker, 2016) levels.
In relation to LCA studies on bread as a product, the environmental impacts of the
of
production and consumption of bread in the United Kingdom have been assessed for white
ro
and wholemeal bread (Espinoza-Orias et al., 2011), loaf of bread, (Goucher et al., 2017),
-p
traditional durum-bread in the region of Sicilia, Italy (Ingrao et al., 2018) and bread
re
production in Indonesia (Laurence et al., 2018). Two publications evaluated different types
lP
of bread which are traditionally consumed in the European countries (Kulak et al., 2015;
na
Notarnicola et al., 2017b).
Within this context, this paper attempts to combine a broader approach to the
Jo ur
environmental assessment of an artisanal product, in which the quality of the cereal and the product are fundamental variables. Not only must it be produced sustainably, but it must also ensure that the product achieves premium quality. This study adds greater scientific relevance in this field by comparing the different systems of wheat cultivation in this region. In addition, two different bread production scenarios are compared, one using wheat grains produced under crop rotation and the other under monoculture systems.
2. Materials and methods
2.1 Area of study 5
Journal Pre-proof
The study area comprises three regions of Galicia (Figure 1): Carral, Laracha and Xinzo. The three regions represent a population of approximately 27,000 dwellers and 300 square kilometres of surface area. The inventory data for the environmental assessment correspond to 51 farmers supplying Galician wheat grains to a single bakery. With an area of 320 hectares (ranging from 0.4 to 7 ha), they produce the traditional wheat of Galicia, called
of
"trigo del país", with an average annual production of 1500 t·year-1.
ro
Most agricultural wheat fields go through a crop rotation system, which uses only organic
-p
composting material as fertiliser. The different types of crop rotation are: 1) Wheat,
re
rapeseed and lupine in the Carral region; 2) Wheat and maize in the Laracha region; 3)
lP
Wheat and potatoes in the Xinzo region. Although to a lesser extent, wheat farming under a
na
monoculture system is also carried out in these regions.
Jo ur
2.2 Goal and Scope
Life cycle assessment (LCA) is an interesting tool to provide a comprehensive analysis of the environmental impacts throughout a product life cycle. This study has a twofold perspective: 1) to perform a cradle-to-farm LCA of different types of wheat cultivation and 2) a cradle-to-Galician bread LCA. The boundaries of the system for wheat and bread production are depicted in Figure 2. In the cultivation process, 1 kg of wheat grain was selected as the functional unit (FU). In the stages of bread preparation, the FU of 1 kg of bread was selected because it is the average weight of a common Galician bread and also to
6
Journal Pre-proof facilitate comparison with other studies using similar FU (Kulak et al., 2015; Notarnicola et al., 2017b).
Iana Câmara Salim, Fernando Almeida-García, Sara GonzálezGarcía, Angeles Romero-Rodríguez, Benigno Ruíz-Nogueiras, Santiago Pereira-Lorenzo, Gumersindo Feijoo, Maria Teresa Moreira PII:
S0048-9697(20)30230-8
DOI:
https://doi.org/10.1016/j.scitotenv.2020.136720
Reference:
STOTEN 136720
To appear in:
Science of the Total Environment
Received date:
8 October 2019
Revised date:
13 January 2020
Accepted date:
14 January 2020
Please cite this article as: I.C. Salim, F. Almeida-García, S. González-García, et al., Life cycle assessment of autochthonous varieties of wheat and artisanal bread production in Galicia, Spain, Science of the Total Environment (2020), https://doi.org/10.1016/ j.scitotenv.2020.136720
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. 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.
© 2020 Published by Elsevier.
Journal Pre-proof Life cycle assessment of autochthonous varieties of wheat and artisanal bread production in Galicia , Spain
Iana Câmara Salim1,a*, Fernando Almeida-García2,4*, Sara González-García1 , Angeles Romero-Rodríguez3, Benigno Ruíz-Nogueiras4, Santiago Pereira-Lorenzo4, Gumersindo
of
Feijoo1 and Maria Teresa Moreira1
(2) Grupo Da Cunha. 15175 Carral. Spain.
-p
Compostela. 15782 Santiago de Compostela. Spain.
ro
(1) CRETUS Institute. Department of Chemical Engineering. Universidade de Santiago de
lP
Compostela. 27002 Lugo. Spain.
re
(3) Department of Analytical Chemistry, Faculty of Sciences Universidade de Santiago de
na
(4) Dept. of Crop Production and Engineering Projects. High Polytechnich School of
a
Jo ur
Engineering. Universidade de Santiago de Compostela. 27002 Lugo. Spain.
Corresponding author
* These authors contributed equally to this work.
Abstract
For millennia, bread and wheat have been one of the most important sources of nutrients in many civilizations. Today, mechanization and evolution in agriculture and food processing have intensified yields and modified the biological and nutritional aspects of multiple crops and foods. The Galician bread is a reference value of food heritage in Spain, which is made 1
Journal Pre-proof from common wheat grain and is a mixture of indigenous Galician wheat and conventional Spanish wheat. In the pursuit of product excellence, it is interesting to identify the environmental profile as support criteria in decision-making, not only to analyse product environmental sustainability, but also as a marketing element to improve consumer awareness. The paper has a twofold perspective to analyse the environmental burdens of wheat
of
cultivation and the bread sector, using life cycle assessment approach: 1) the comparison of
ro
the different types of agricultural systems, i.e. the cultivation of Galician wheat following a
-p
strategy of monoculture and crop rotation, certified Galician seed production and its comparison with conventional wheat cultivation and 2) the environmental profile of Galician
lP
facility and 1 kg of Galician bread.
re
bread. The functional units chosen were 1 kg of wheat grain transported to the milling
na
The results show that wheat cultivation presents the main environmental impacts of bread production, mainly due to the use of agrochemicals and field emissions. The best cultivation
Jo ur
scenario corresponds to a crop rotation system, since chemical fertilisation is not applied. In comparative terms with many staple foods produced in Europe, Galician bread has a low environmental impact. The overall environmental results of bread production draw attention to the dependence of bread and flour manufacturers on the agricultural sector, highlighting the need to share responsibilities across the supply chain. In addition, this study contributes to the stakeholder debate on environmental impacts related to food heritage.
Keywords: crop rotation system, life cycle assessment, food heritage, bread production, wheat cultivation
2
Journal Pre-proof
1. Introduction
Wheat was and remains one of the main staple foods of many civilizations. Different types of genetic diversity crops have been developed for different consumption purposes. About 95% of the world production is common wheat, also called bread wheat (Triticum aestivum) and the remaining 5% is durum wheat (Triticum durum), mainly for the production of pasta
of
and couscous (Taylor, 2017). Milling and baking industries evaluate wheat composition (e.g.,
ro
starch and protein content) and other specifications (e.g., bulk density and shape) to meet
-p
their demand (Mancuso et al., 2019).
re
Currently, there are about 219 million ha of wheat-growing areas in the globe. World
lP
production amounts to 770 million t, of which 5 countries (China, India, Russia, USA and
na
France) account for more than half of the world production (FAOSTAT, 2018). In Europe, total production represents about 150 million tonnes, with Spain representing only 3% of
Jo ur
total European production, concentrated mainly in the autonomous regions of Castilla y León and Andalusia (Calatrava et al., 2018).
In Galicia, wheat cultivation is less representative in quantitative terms (about 0.5% of Spanish production). The grain of native Galician wheat can be classified in the varieties of wheat "Caveeiro" and "Callobre", which is a winter (mainly sown in autumn and harvested in late spring or early summer) and soft wheat that, compared to durum wheat, has more starch and less gluten. Surprisingly, Galician bread is a reference of quality at national level, which is largely attributed to the variety of native wheat that offers a distinct flavour and taste to bread as well as to its differentiated production scheme, such as the use of
3
Journal Pre-proof fermented dough and the requirement of long times of fermentation and baking in stone ovens. In an increasingly industrialised agriculture, the search for more traditional varieties that preserve the genuine organoleptic properties of bread is a growing demand. In this sense, the consumer is not only interested in preserving the food heritage associated with ingredients and artisanal production techniques (Kulak et al., 2015), but also prefers to buy a product of higher quality and taste, accredited as organic or produced according to
of
sustainable production patterns (Ingrao et al., 2018). Beyond product excellence, the
ro
assessment of the environmental profile associated with agricultural activities can provide
-p
information on the strategy for marketing healthier and more sustainable food products.
re
Life cycle assessment (LCA) is an interesting tool to have a broad environmental perspective
lP
of the production chain. The International Standards ISO 14040 and 14044 (ISO14040, 2006; ISO14044, 2006) establish principles and guidelines to perform LCA, using four important
na
steps: goal and scope definition, life cycle inventory assessment (LCI), life cycle impact
Jo ur
assessment (LCIA) and interpretation. LCA is capable of evaluating all the activities involved in the production of the crop and may involve the stages from agrochemical production, agricultural activities, transport, storage, delivery, consumption and end-of-life. The system boundaries vary for each case study, depending on the reliability of the data and the purpose of the study.
There are different LCA studies on wheat cultivation. A number of authors have investigated wheat cultivation for non-food markets, such as for bioenergy systems (De Matos et al., 2015; Gissén et al., 2014; Muñoz et al., 2014; Röder et al., 2015). Others have focused on common wheat varieties (Mancuso et al., 2019) and different management practices, e.g. comparison of different winter wheat cropping systems (Cambria et al., 2016); and the use 4
Journal Pre-proof of crop rotation systems (Wang et al., 2014). There are also references of interest in which wheat crops are compared with other arable crops (Romeiko, 2019; Williams et al., 2010). Inventory data in the different studies have been identified at regional (Noya et al., 2015; Tabatabaie et al., 2016), country (Liang et al., 2018) and continental (Achten and Van Acker, 2016) levels.
In relation to LCA studies on bread as a product, the environmental impacts of the
of
production and consumption of bread in the United Kingdom have been assessed for white
ro
and wholemeal bread (Espinoza-Orias et al., 2011), loaf of bread, (Goucher et al., 2017),
-p
traditional durum-bread in the region of Sicilia, Italy (Ingrao et al., 2018) and bread
re
production in Indonesia (Laurence et al., 2018). Two publications evaluated different types
lP
of bread which are traditionally consumed in the European countries (Kulak et al., 2015;
na
Notarnicola et al., 2017b).
Within this context, this paper attempts to combine a broader approach to the
Jo ur
environmental assessment of an artisanal product, in which the quality of the cereal and the product are fundamental variables. Not only must it be produced sustainably, but it must also ensure that the product achieves premium quality. This study adds greater scientific relevance in this field by comparing the different systems of wheat cultivation in this region. In addition, two different bread production scenarios are compared, one using wheat grains produced under crop rotation and the other under monoculture systems.
2. Materials and methods
2.1 Area of study 5
Journal Pre-proof
The study area comprises three regions of Galicia (Figure 1): Carral, Laracha and Xinzo. The three regions represent a population of approximately 27,000 dwellers and 300 square kilometres of surface area. The inventory data for the environmental assessment correspond to 51 farmers supplying Galician wheat grains to a single bakery. With an area of 320 hectares (ranging from 0.4 to 7 ha), they produce the traditional wheat of Galicia, called
of
"trigo del país", with an average annual production of 1500 t·year-1.
ro
Most agricultural wheat fields go through a crop rotation system, which uses only organic
-p
composting material as fertiliser. The different types of crop rotation are: 1) Wheat,
re
rapeseed and lupine in the Carral region; 2) Wheat and maize in the Laracha region; 3)
lP
Wheat and potatoes in the Xinzo region. Although to a lesser extent, wheat farming under a
na
monoculture system is also carried out in these regions.
Jo ur
2.2 Goal and Scope
Life cycle assessment (LCA) is an interesting tool to provide a comprehensive analysis of the environmental impacts throughout a product life cycle. This study has a twofold perspective: 1) to perform a cradle-to-farm LCA of different types of wheat cultivation and 2) a cradle-to-Galician bread LCA. The boundaries of the system for wheat and bread production are depicted in Figure 2. In the cultivation process, 1 kg of wheat grain was selected as the functional unit (FU). In the stages of bread preparation, the FU of 1 kg of bread was selected because it is the average weight of a common Galician bread and also to
6
Journal Pre-proof facilitate comparison with other studies using similar FU (Kulak et al., 2015; Notarnicola et al., 2017b).
2.3 System description 2.3.1 Galician wheat (“trigo del país”) (S1a -CR; S1a-M and S1c)
of
The subsystem S1a-CR represents wheat grown with a crop rotation system. One of the
ro
advantages of crop rotation is nutrient sequestration in the soil, avoiding costs and pollution
-p
by additional chemical fertilisation. However, longer periods are required to grow wheat. This system uses only rabbit straw manure as fertiliser. On the other hand, S1a-M
re
represents wheat under a monoculture system, characterized by the use of rabbit straw
lP
manure and ammonium nitrate. Additional field operation is required to apply chemical
na
fertiliser; therefore, more impacts associated to increased diesel consumption and
Jo ur
machinery use are expected.
The wheat cultivation takes place after the harvest of the previous crop. Agricultural activities start with the field establishment, where the soil is prepared for sowing. Firstly, the tillage process with the use of a disc plough is carried out in November-December. In parallel, slurry is applied through a manure spreader. This slurry is composed of wheat straw (50%) and rabbit manure (50%). After 15 days, the seeds are scattered on the ground (about 135 kg seed·ha -1). After the sowing process, the crop growth phase takes place. In 2-3 days, a spraying machine applies herbicides, i.e. Prosulfocarb and Diflufenican. In FebruaryMarch, chemical fertilisation with ammonium nitrate is applied, only when crop rotation is not carried out in the fields. In May-June, a spraying machine applies fungicides
7
Journal Pre-proof (Tebuconazol) and finally in July-August wheat is harvested with a combine harvester, separating the wheat grain from the straw. The period between August and November corresponds to a fallow period for the land to regenerate its original state of productivity. Table 1 shows the inventory and field operations by agricultural stage of the production of Galician wheat grains.
This wheat grain has about 11-13% moisture, 13-14% protein and a bulk density of 70-75
of
kg·hL-1. Having the correct density is very important, as it is a grain quality standard for
ro
market purposes (Charrondiere et al., 2012). The transport of grain varies from 20 to 200 km
-p
from the farm to the milling plant. However, 50% of production is between 2 and 50 km
re
away. In this cultivation system, 100% of the straw is removed from the field. Half of the
lP
wheat straw is used for animal feed and the rest sent to composting. The weight of the straw corresponds to 40% of the weight of the wheat grain. The transport of the straw was
na
not taken into account, as the composting process is carried out in the field and the
Jo ur
remaining straw used for animal feed was considered to be delivered at a very close distance, and therefore can be disregarded.
A part of the land is reserved for the production of wheat seeds from Galicia (S1c). Of the total grains, between 20 and 25% do not reach the specific weight necessary to be certified as native Galician seeds. Rejected seeds are used directly for flour production. Seed production uses the same agricultural activities mentioned above for Scenario S1a-CR and S1a-M. The only exception is the selection of seeds after the harvesting process. The grain passes through a series of cleaning and sorting machines. The aim is to select the grain with the highest specific weight, also discarding weeds and other impurities. All the Galician scenarios S1a-CR, S1a-M and S1c have the same yield of 2500 kg·ha-1. 8
Journal Pre-proof 2.3.2 Conventional Spanish wheat (S1b) This subsystem (S1b) takes place after the harvest of the previous crop. This stage represents a typical wheat production in the regions of Castilla y León and Andalusia (Spain), with average yield of 3000 kg·ha-1 and at a moisture content of 15%. This wheat represents a conventional variety of grains and, due to weather conditions, irrigation is required. Straw
of
The subsystem S1a-CR represents wheat grown with a crop rotation system. One of the
ro
advantages of crop rotation is nutrient sequestration in the soil, avoiding costs and pollution
-p
by additional chemical fertilisation. However, longer periods are required to grow wheat. This system uses only rabbit straw manure as fertiliser. On the other hand, S1a-M
re
represents wheat under a monoculture system, characterized by the use of rabbit straw
lP
manure and ammonium nitrate. Additional field operation is required to apply chemical
na
fertiliser; therefore, more impacts associated to increased diesel consumption and
Jo ur
machinery use are expected.
The wheat cultivation takes place after the harvest of the previous crop. Agricultural activities start with the field establishment, where the soil is prepared for sowing. Firstly, the tillage process with the use of a disc plough is carried out in November-December. In parallel, slurry is applied through a manure spreader. This slurry is composed of wheat straw (50%) and rabbit manure (50%). After 15 days, the seeds are scattered on the ground (about 135 kg seed·ha -1). After the sowing process, the crop growth phase takes place. In 2-3 days, a spraying machine applies herbicides, i.e. Prosulfocarb and Diflufenican. In FebruaryMarch, chemical fertilisation with ammonium nitrate is applied, only when crop rotation is not carried out in the fields. In May-June, a spraying machine applies fungicides
7
Journal Pre-proof (Tebuconazol) and finally in July-August wheat is harvested with a combine harvester, separating the wheat grain from the straw. The period between August and November corresponds to a fallow period for the land to regenerate its original state of productivity. Table 1 shows the inventory and field operations by agricultural stage of the production of Galician wheat grains.
This wheat grain has about 11-13% moisture, 13-14% protein and a bulk density of 70-75
of
kg·hL-1. Having the correct density is very important, as it is a grain quality standard for
ro
market purposes (Charrondiere et al., 2012). The transport of grain varies from 20 to 200 km
-p
from the farm to the milling plant. However, 50% of production is between 2 and 50 km
re
away. In this cultivation system, 100% of the straw is removed from the field. Half of the
lP
wheat straw is used for animal feed and the rest sent to composting. The weight of the straw corresponds to 40% of the weight of the wheat grain. The transport of the straw was
na
not taken into account, as the composting process is carried out in the field and the
Jo ur
remaining straw used for animal feed was considered to be delivered at a very close distance, and therefore can be disregarded.
A part of the land is reserved for the production of wheat seeds from Galicia (S1c). Of the total grains, between 20 and 25% do not reach the specific weight necessary to be certified as native Galician seeds. Rejected seeds are used directly for flour production. Seed production uses the same agricultural activities mentioned above for Scenario S1a-CR and S1a-M. The only exception is the selection of seeds after the harvesting process. The grain passes through a series of cleaning and sorting machines. The aim is to select the grain with the highest specific weight, also discarding weeds and other impurities. All the Galician scenarios S1a-CR, S1a-M and S1c have the same yield of 2500 kg·ha-1. 8
Journal Pre-proof