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Use of energy and labour in Italian agriculture
J. agric. Engng Rex (1992) 52, 111-119
Use of Energy and Labour in Italian Agriculture G. Institute
of Agricultural
(Received
Engineering,
21 March
PELLIiZl
University
1991; accepred
of Milan,
Via
in revised
form
Celoria
2, 20133
17 October
- Milano,
Italy
1991)
Over the course of 4 consecutive years, an energy analysis was carried out on more than 200 representative Italian farms. The analysis was based on internationally recognized standardized methods. This paper presents the results obtained which represent 87% of Italian agriculturally used area and covers products such as cereals, industrial and vegetable crops, forage crops and fruit tree crops. Analyses were also carried out on cattle, sheep and goat breeding farms. For each sector, the analysis was broken down into direct energy use (fuel and electricity) and indirect energy incorporated in the various means of production. Consumption per hectare, specific consumption per unit at output and the employment of labour were calculated. The results obtained are comparable to those contained in the international literature. Total energy consumption proved to be 13Mt of oil equivalent per year, 35% of which is represented by direct energy. The employment of human labour corresponds to 1.4M full-time working units, one full-time working unit being equal to 1900 h/a. 1. Introduction
Italy consumes approximately
140 Mt of oil-equivalent (Mtoe) per year and over 80% are met by foreign sources. Official national statistics pay very little attention to the energy consumption of agriculture, for a number of reasons. First, only fuel purchased by farmers at subsidized prices is considered when analysing fuel consumption for agricultural and animal production. Second, diesel oil and gasoline purchased directly by farmers from normal service stations are excluded and classified in the transport sector. Third, only the percentage of total electricity consumption related to connections for agricultural uses is included in the agricultural sector; this involves approximately 400,000 farms with a total consumption of 1.8 MWh/a but there are, in fact, 2.2 M farms and their electrical usage for agriculture is attributed to household consumption. Fourthly, all indirect energy consumption (i.e., the energy embodied in the technical means needed for agricultural production, namely fertilizers, pesticides, seeds and machinery) is included in the “industrial” sector. After a preliminary analysis’ carried out by the CNR (Italian National Research Council) in 1980 and an in-depth document* prepared by the CNEL (National Council on Economy and Labour) in 1982 (in which the energy consumption of the whole agricultural-food production system was thoroughly examined for the first time in Italy), a wide-ranging3 study was considered to be necessary to provide further clarification of the subject. This investigation was part of the 5-year CNR National Energy Research Programme. of the country’s energy requirements
2. Scope of study The study
was carried
research institutes
out over
the course
of 4 years
located in various parts of Italy. 111
with
the cooperation
The first step was definition
of 13
of a
112
USE
OF
ENERGY
AND
LABOUR
IN
ITALIAN
AGRICULTURE
common operative methodology based on the evaluation of gross energy requirements identified 15 years ago by a working group sponsored by the International Federation of According to this method, calculations Institutes for Advanced Studies in Stockholm.W should not include any renewable energies, such as solar energy, whose availability does not require any conventional sources.
Primary
energy
incorporated means
Table 1 (average) of production
Means
MJ/kg MJ/kg MJ/kg manure
MJ/kg
Pesticides & herbicides* Pesticides Herbicides Insecticides
.MJ/kg
Seeds & propagation materials Cereals and forage Potatoes Sugarbeet Vegetables (leguminous) Vegetables (not leguminous) Bulbs Seedlings
MJ/kg MJ/kg MJ/kg MJ/kg MJ/kg
Feedstuff Forage Maize for ensiling Concentrate Milk powder Straw
MJ/kg MJ/kg MJ/kg
Lubricants
MJ/kg
MJ/unit MJ/unit
8-10 1.2-1.5 12-16 100-120 0.5
concrete
a
9-10
MJ/kg MJ/kg
a a
8-10 6-8
MJ/m’ MJ/m’ MJ/m’
a a a
32-38 2.5-3.0 70-80
MJ/kg
MJ/kg MJ/kg MJ/kg
MJ/kg product.
SO-85
MJ/kg
MJ/kg MJ/kg
* Per kg of commercial
9-12 2.2-2.6 2.0-2.4 18-22 47-55 I.5 0.2
MJ/kg MJ/kg
Buildings Cowsheds Hedges Greenhouses Materials Masonry Concrete Reinforced Wood Wire Plastics Twine
50-60 x5-95 50-55
MJ/kg MJ/kg
Tractors & agricultural machines Tractors and self-propelled machines Stationary equipment Agric. machinery & implements
technical
73-75 13-14 9-10 IO 0.4
MJ/kg
pzo,
main
Primary energy
Units
Fertilizers N K,O Mg Rotted
in the
2.0-2.2 1.1-1.3 2.8-3.0 2.4-2.6 40-45 100-130 8-12
G.
113
PELLIZZI
A preliminary decision was made also as to the value to be attributed to the energy incorporated in technical means of production; these values were calculated on the basis of the consumption of conventional energy sources in the various production processes (Table 1).7 Consequently, in the case of all mineral fuels, the added costs represented by the energy needed for their production (up to the “refinery gates”) were also taken into consideration. In the case of electric energy, moreover, the equivalent energy in terms of primary sources was calculated on the basis of the average efficiency for production and distribution of the Italian electric grid. This means that 1 t of diesel-oil corresponds to 1.2 toe; 1 t of gasoline to 1.32 toe; 1 t of LPG to 1.4 toe and 1 MWh of electricity to 0.25 toe, where 1 toe = 42 GJ. Furthermore, it was decided not to apply any energy value to human labour, since consumption connected with the daily requirements of farmers and farmworkers (as well as those of the population in general) are classified as “domestic use” and “transport” in the national statistics. Therefore, man-hours registered were reported as such without any transformation into energy units. Over 40 main crops were studied in the field for 4 consecutive years on 200 farms located in different parts of Italy. The various farms have been chosen on the basis of their representativeness (size, production system, crop rotation adopted, income and mechanization levels, labour productivity etc.) of the different areas considered, subdivided according the various pedo-climatic conditions. These crops cover approximately 13.5 Mha of agriculturally used area (1987 data), 34% of which was cultivated with cereals, 31% with temporary and permanent grassland, 22% with fruit tree crops and grapes and the remaining 13% with industrial and vegetable crops. Therefore, the analysis concerned 87% of total agriculturally used land, the remaining 13% being cultivated with minor crops. Land used for grazing (3.8 Mha) and forests (6.7 Mha) was excluded. The analysis was completed by an investigation into dairy and beef cattle, sheep and goat farms. The different farms were chosen with the same criteria above mentioned for crops. In the final calculations the energy spent for forages has been included in the energy consumption requested for animal production.
3. Results
obtained
The results obtained on the most important crops are summarized in Tables 2 to 6 and are shown by type of production. In the various tables the maximum and minimum energy consumption figures registered in the different conditions studied have been reported. To calculate the total energy consumption of the various production sectors we considered the registered figures (per ha and/or per kg of output) in the different farms and multiplied them by the areas (or the number of animal heads) where the same production processes are used and similar yields obtained.
3.1. Cereals Unit consumption (Table 2) varies from 4 to 8 MJ/kg of harvested product, which corresponds to a consumption per unit of cultivated area between 12 and 54 GJ/ha. If the extent of the area planted with various species is taken into account (totaling just over 4.5 Mha), then total consumption turns out to be 3.2 Mtoe/a. Approximately half of this figure is represented by the production of winter-type grains and 30% by maize. The energy consumed by straw collection (a total of approximately O-3 toe/a) must also be added to this value.
114
USE
OF
ENERGY
Table Energy
consumption
AND
LABOUR
IN
ITALIAN
AGRICULTURE
2
for the cultivation
of cereals Species
l/nil
of Consumpfion Direct Indirect
measure
energy energy
Machinery Lubricants Fertilizers Pesticides Seeds Buildings Consumable
materials
Total consumption Specific consumption Human labour * Including 1.5-2 MJ/kg,
Durum wheor
sofl wheat und burley
Maize
Rice
% 5%
30-W X-70
20-35 65-80
45-W* 40-55
27-35’ G-73
% 8 % % % o/o o/o
3-7 l-2 2X-54 1-3 6-11 1-2 0.5 I
3-7 1-2 36-63 l-2 4-10 l-2 0.5 I
4-10 l-2 30-40 2-3 l-2 l-3 0.5 1
4-7 1-2 35-40 II-16 24 2-3 Y.5-I
12-20 4-x 16-22
12-23 3.5-4.5 19-30
20-54 4.2-8.4 13-40
30-34 5.4-X.3 27-34
GJ/ha MJ/kg h/ha
drying. The harvesting of which corresponds to 3.5-4.0
wheat MJ/ha
straw results in consumption with 5 h/ha of labour.
figures
of
On average, direct energy consumptions (fuels and electricity) represent 35% of the total and thus correspond to just under 1.4 Mtoe/a. These values are lower in the case of wheat and wheat-like crops (approximately 30% of the total) and higher for maize and rice mainly due to drying requirements. The amount of energy required by fertilizers is also high (averaging 40%), while pesticides and herbicides have a marginal value (in purely energy terms), which does not exceed 3% except in the case of rice, where it represents 11 to 16% of the total. The amount of energy that may be attributed to seeds is also high in the case of winter sown cereals and rice. It represents respectively between 4 and 11% of the total consumption as far as wheat is concerned and 24% as for rice. Finally, the amount of human labour employed does not exceed 40 h/ha and frequently falls below 20 h/ha. 3.2. Industrial
and vegetable crops
This group of crops (Table 3) is extremely heterogeneous, and therefore the main species are discussed separately below. The energy required for the production of sugarbeet, which is cultivated on just over 300,000 ha, varies widely depending on the location considered. However, if we assume an average value of 50 GJ/ha, total consumption turns out to be 0.37 Mtoe/a, approximately half of which is represented by direct energy. Fertilizers represents about 75% of indirect consumption. The significant differences observed in various situations seem mainly to be owing to the physical and structural properties of the soil considered. Indeed, for clay soils, direct consumption is almost double that of loamy soils. The amount of labour required varies from 25 to 105 h/ha in the different geographical areas, depending on the type of mechanization adopted as well as on the irrigation practices required in southern areas. The energy required for the production of potatoes, which are cultivated on just over 130,000 ha, is approximately 35 GJ/ha, which corresponds to a total consumption of
G.
115
PELLIZZI
Table Energy
consumption
for the cultivation
3 of some industrial
and vegetable
crops
Species i/nil of memsure
Comwnption
Sugar beer
Poruioes
Soybeans
Sunflowers
Totnoloes
33-46 54-67
JO-63 37-60
45-55 45-55
1 .s-3.5 1.5-3.5 40-46 2.5-4.3 ws- I .2 o.s- I ws- 1
5-12 1.5-3.5 20-30 2-g 0.1-0.6 0.X-1.2 0.5-0.9
3.5-5 2-26 20-35 l-l.5 x-10 0.5-1.2 0.3-0.7
IX-23 5.6-10 25-55
34-50 0~6-0~9 167-997*
30-35 4-15 30-Ytl
Direct energy energy Indirect
% o/r
36-59 41-64
30-35 65-70
U-70 30-56
Machinery Lubricants Fertilizers Pesticides Seeds Buildings Consumable
% % %I ?4 % 74 o/u
2-6 l-l.5 32-49 I .5-4 l-1.2 l-l.2 0.5-0.7
IO-12 I-S 25-40 l-I.5 12-17 0~5-1 0.5- 1
2.5-6.5 1.5-3.7 IS-35 0-5-5.6 s-15 0.5-1.2 0.5-I
35-70 0.7-1.9 40- I05
32-3X WY- I.5 ho-430*
15-30 4-1s 13-43
materials
Total consumption Specific consumption Human labour * Manual
GJ/ha MJ/kg h/ha
Kidney and green beam
Peas 38-44 56-62 6-7 2-2.5 30-35 I .5-2.5 12-15 0.5-l .2 0.2-0.6 20-26 4-5 20-25
harvesting.
110,000 toe/a. Fuel and fertilizers each represent 30-35% of this figure. In addition, seeds and machinery each contribute lo-17% to the total. However, manual harvesting or single-operation machines are still used in many areas, as confirmed by the intensive employment of labour. Therefore, an increase in direct energy consumption due to the development of mechanization should be expected in the future. On fully mechanized farms, in fact, direct consumption ranges from 240 to 280 kg/ha of oil equivalent while labour required drops to a minimum of 25 h/ha. Average unit consumption in the case of soybeans, which are cultivated on just under 480,000 ha, is of the order of 22 GJ/ha; this figure is approximately equally divided between indirect and direct energy. This results in a total consumption of 250,000 toe/a in round figures. About half of all direct consumption is related to irrigation, which means that in areas in which this is not strictly necessary there is a significant drop in the total energy requirement. Once again, fertilizers represent the highest percentage of indirect consumption, while values vary widely as far as consumption related to pesticides is concerned (from 0.5 to 5.6%). Seeds represent up to 16% of total consumption. Figures on labour range from 13 to 43 h/ha with considerable differences among the various situations; this is partially due to the irrigation practices. Average consumption in the case of sunflowers, which cover almost 110,000 ha, is 20 GJ/ha and corresponds to just under 53,000 toe/a; approximately 40% of this is represented by fuel. The most important form of indirect consumption concerns fertilizers, which represent an average of 45% of the total. Finally, this crop requires a relatively limited amount of labour, that is, about 30 h/ha. Tomatoes also cover just over 110,000 ha and require (in the case of varieties grown for industry purposes) widely divergent amounts of energy depending on the cultivation method employed. In fact, open-field crops consume 40-50 GJ/ha (corresponding to just over 110,000 toe/a); this figure is approximately equally divided between direct and indirect energy. In cases in which plastic mulching is used, consumption increases to over 240 GJ/ha and 3.5 MJ/kg of harvested product. Figures on the amount of labour required range from averages of 160-170 h/a, where mechanical harvesting is employed, to almost 1000 h/ha in the case of manual harvesting. Finally, total energy consumption in the case of beans (kidney and green) and peas,
116
USE
OF
ENERGY
AND
LABOUR
IN
ITALIAN
AGRICULTURE
which cover approximately 70,000 ha, is 50,000 toe/a with specific consumption between 4 and 15 MJ/kg. When mechanical harvesting is used on these crops, labour does not exceed 30 h/ha. 3.3. Fruit tree crops Values concerning this group of crops (Table 4) show a relative homogeneity of energy consumption, which totals about 40 GJ/ha. This figure corresponds to 2.9 Mtoe/a (50% of which is represented by fuels) over a total cultivated area of approximately, 3 Mha. A considerable amount of energy is used in fertilizers, with maximum values reached in the case of citrus fruit and minima in that of fleshy fruit. Pesticides also represent a high percentage of indirect energy in the case of fleshy fruit and grapes. When manual harvesting is employed, figures on labour exceed 1000 h/ha (as in the case of lemons). This figure drops to 200-230 h/ha when appropriate grape-harvesting equipment is used. 3.4. Forage crops Italian forage production takes place on approximately 4.2 Mha of temporary and permanent grassland. The energy consumption connected with these crops (Table 5) averages between 15 and 20 GJ/ha. This means that total consumption is in the order of 1.2 Mtoe/a; the major portion of this figure is represented by mechanization (including irrigation and artificial drying) and fertilizers. Permanent grassland requiring no more than 1.5 MJ/kg of fresh grass, consume the least amount of energy, while temporary meadows consume approximately double. In the case of hay, consumption reaches 3.5 MJ/kg. This value increases to 4.4 MJ/kg when two-stage drying with hot air is employed; however, this method raises yields per hectare and improves forage quality. Obviously, significant differences are met between irrigated and non-irrigated areas and, in the former case, with regard to the irrigation system adopted. On average, labour is employed for 30 h/ha, with minima of 14-15 h/ha. With regard to maize for ensiling, an average energy consumption of 35 GJ/ha results corresponding to less than 1 MJ/kg of harvested product because of high yields. If these
Table Energy
consumption
4 for fruit
tree crops Species
Unil
of Consumprion Direct Indirect
measure
energy energy
Machinery Lubricants Fertilizers Pesticides Buildings Consumable
materials
Total consumption Specific consumption Human labour * Manual harvesting; t The highest values
Fleshy Cirrus
Grapes
Olives
.-
!““L.
_
NuL
% %
25-34 66-75
35-w SO-65
JO-60 40-60
40-50 40-60
25-35 65-75
% % % % %
1.7-2 0.5-1.2 45-73 2-3 1.5-2
6-12 1-2 30-40 6-9 l-1.5
6-12 1.2-1.5 20-30 l-2 0.1-0.5
4-12 l-l.5 g-12 12-25 l-3
7-15 0.X-1.4 40-55 1-3 -
%
14-15 -.--~~~.
S-10
2-5 _-~~~
4-6
2S-45.t 1.5-2.9 230-350
30-50 4.5-6 350-470
38-43 1.2-2 300-700
W/ha MJ/kg h/ha higher values are observed
40-47 1.2-1.5 490- 1300* apply in the case in southern areas.
of lemons.
l-2 20-32 6-10 100-130
G.
117
PELLIZZI Table Energy
consumption
for
the
Unir Of measure Direct Indirect Machinery Lubricants Fertilizers Pesticides Seeds Buildings Consumable
materials
Total consumption Specific consumption Human labour * Up t Up
of grass
GJ/ha h/ha
and
forage
cereals
Maize
for
ensiling
42-50 50-58
SO-70 30-50
35-so* SO-65
25-45 55-75
5-6 I .5-2.5 30-45 -
12-15 3-4 X-12 -
5-u 2-4 35-50 -
I .5-4 l-2 I .5-2
l-3 1-3
3-4 2-3 2-4
4-6.5 1.5-3 35-45 l-3 0..5- 1 1.5-3 I-1.5
20-25 I .2-3 14-20
MJ/kg
land
Species Hay from Pcrmanenr iemporary grassland grassland
Temporary grassland
% %
energy energy
5
cultivation
7-17 0.3-1.5 30-40
1X-27 2-3.5t 15-23
25-45 0.5-0.9 25-40
to 75% in the case of two-stage, artificial hay-making; to 4.2 MJ/kg in the case of two-stage hay-making.
values are extrapolated to include all of the 1.4 Mha cultivated, then total consumption turns out to 1.2 Mtoe/a. The amount of labour required varies from 25 to 40 h/ha. 3.5. Animal
breeding
In this case (Table 6), the energy analysis, which, as mentioned above, includes consumption related to forage production and the majority of the straw harvested, has been divided up-as far as cattle, sheep and goats are concerned-into milk and meat production.* In the former case, average consumption related to milk cattle is 10 GJ/t produced. Taking into account that cow milk production is in the order of 8.7 Mt/a, then total consumption turns out to be 2.1 Mtoe/a, only about 10% of which is represented by Table Energy
consumption
for
6 animal
production
Species
Consumption Direct Indirect
~__~
~--
Unir of measure
energy energy
Milk cattle
Milk sheep
Beef carrle
“/a %
7-15 85-93
6-10 90-94
30-40 60-70
Machinery Lubricants Feed Forage Bedding
% % % % %
1.4-3 0.3-0.5 SO-60 IS-20 0.7- 1
0.5-2 0.3-0.4 12-18 W-75
6-8 1-3 50-60
Buildings
%
5-11 ~~ -..-
l-2
3-5
20-25 20-25 25-30
60-70 6-7 12-18
-~~-~
Total consumption Specific consumption Human labour * per
unit
weight
GJ/t* MJ/kg* h/t* of milk
or beef
10-12 7-13 5-20
-
118
USE
OF
ENEKGY
AND
LABOUK
IN
ITALIAN
AGRICULTURE
direct energy. Of the other energy users involved, an average of 55% is attributable to concentrated feed and 17% to forage. The percentage represented by buildings is also high. Figures on the amount of labour employed vary from a minimum of 5 h/t (in the case of large, highly mechanized herds) to a maximum of 20 h/t of milk produced. In the case of sheep and goat milk, average consumption is approximately 22 GJ/t of product, which corresponds to O-9 Mtoe/a; the main portion of this figure is represented by forage. The amount of labour required ranges from 25 to 30 h/t of product. Finally, in terms of beef production, which totals 900,000 t/a. consumption is 6-5 GJ/t, which corresponds to 140,000 toe/a. In this case, direct energy consumptions represent 35% of the total, while feed covers 55%. The average amount of labour required is 15 h/t. In addition, the yearly production of lamb and goat meat (70,000 t/a), pork (1.2 Mt), horse meat (54,000 Mt), and fowl (1 Mt/a), as well as eggs (11 billion), must also be taken into consideration. If we adopt data from the literature regarding these products3,a it is possible to estimate an additional energy consumption of approximately 2 Mtoe/a. In conclusion, the total consumption related to animal production reaches 5.1 Mtoe/a in round figures. 4. Discussion
The analyses carried out have made it possible to calculate total energy consumption with regard to the agricultural and animal products considered of approximately 12.2 Mtoe/a, about 35% of which is represented by direct energy (4.3 Mtoe). If we recall that the crops considered represent 87% of the total agricultural used area, and if we assume that a cautious estimate of the energy consumption of the remaining 13% is 12GJ/ha, then another 800,000 toe should be added to the figure of 12.2 Mtoe. This average value used of 12 GJ/ha takes into account the various crops cultivated and the figures registered in analyses carried out previously.3 This means a total consumption quite close to 13 Mtoe, 4.5-4.6 Mtoe of which is represented by direct energy. The CNR’s National Research Project on Agricultural Mechanization’ evaluated direct energy consumption (including that of farm dwellings) as 5.07 Mtoe/a. Meanwhile, the Table Comparison
among
the
results Pimentel
obtained and Ilalian analyses MJ/kg
Wheat Maize Rice Potatoes Sugarbeet Kidney & green Peas Hay Maize for ensiling Citrus Grapes Fleshy fruit * per
kg of dry
beans
matter.
3.S4.5 4.2-8.4 5.4-8.3 0.9-1.5 0.7-1.9 4-15 4-s 2-3.5 0.5-0.9 1.2-1.5 1.5-2.9 I .2-2.0
7 and Slesser
the
figures
Pimenrel
MJlkg 3-32 3.S 18.5 10.5-12.0 I .3-3. I 10.9-13.9* 8.4’ 1.2-4.x 2.1-3.9* 0.7-1.2 3.0- 15.5 2.0-3.2
provided
Slesser.
MJlkg 0.9- 12 s-11 0.2-12 0.2-3.1 0.5-1.3 0.2-8.3 -
by
G.
119
PELLIZZI
CNEL’ has defined total consumption as 13.5 Mtoe, 63% of which is represented by the energy incorporated in various means of production. Therefore, the analyses carried out confirm these values and indicate that agriculture (i.e., every operation up to the “farm gates”) represents approximately 9% of total energy consumption in Italy. Specific consumptions acquired are comparable to those reported by Pimentel’ and Slesser lo (Table 7). It has to be taken into consideration, that the above papers consider an ample spectrum of conditions in Europe and outside. Finally, it is also interesting to note that, according to this investigation, the total amount of labour employed in the agricultural sector is approximately 1.4 m full-time working units (1 FTWU corresponds to 1,900 h/a). 5. Conclusions The results obtained from the analyses carried out confirm the energy consumption values estimated during previous surveys carried out on a nationwide scale. They are also comparable with the figures shown in international literature. However, as a result of the survey carried out it was possible for the first time to define the consumptions relating to individual crop and livestock products as well as the different amounts of energy consumed as a result of the use of various inputs. An assessmentwas also made of the labour employed in the various crop and livestock production systems, from which it was possible to work out an overall assessment expressed in full-time working units. References L.; Castelli, G.; Pellizzi, G.; Sangiorgi, F. Agricoltura e crisi energetica (Agriculture and energy crisis)-CNR, Progetto Finalizzato Meccanizzazione Agricola. Quaderno n. 18, 1981:46 pp * CNEL, Osservazioni e proposte su Agricoltura ed Energia (Remarks and proposals on Agriculture and Energy)-Rome, 1982,2: 15-78. ’ Bodria,
3 Biondi, P.; Panaro, V.; Pellizzi, G. Le richieste di energia del sistema agricolo italiano (The energy requirements of the Italian agricultural system)-Progetto Finalizzato Energetica,
CNR-ENEA, LB-20. 1989,389 pp. ’ Biondi, P.; Farina, G.; Panaro, V. L’analisi energetica in agricoltura (Energy analysis in agriculture)-Rivista di Ingegneria Agraria 1987, 4: 205-219. 5 IFIAS, Energy analysis-Workshop report n. 6. Stockolm. 1974,46 pp. ’ IFIAS, Energy analysisand economics-Workshop report n. 9, Stockolm, 1975,52 pp. ’ Jarach, M. Sui valori di equivalenza energetica per I’analisi e il bilancio energetic0 in agricoltura (On the conversion factors for the energy analysis and balance in agriculture)-Rivista di Ingegneria Agraria 1985, 2: 102-112. * Pellizzi, G. Meccanica e Meccanizzazione Agricola (Agricultural Machinery and Mechanization)--Edagricole, 1987, 482 pp. ’ Pimentel, D. Handbook of Energy Utilization in Agriculture-CRC Press, 1980: 342 pp. ” Slesser, M.; Wallace, I. Energy Consumption per Tonne of Competing Agricultural Products Available to the E.C.-CEC, Inf. on Agriculture, n”85, 1982: 168 pp.
Use of Energy and Labour in Italian Agriculture G. Institute
of Agricultural
(Received
Engineering,
21 March
PELLIiZl
University
1991; accepred
of Milan,
Via
in revised
form
Celoria
2, 20133
17 October
- Milano,
Italy
1991)
Over the course of 4 consecutive years, an energy analysis was carried out on more than 200 representative Italian farms. The analysis was based on internationally recognized standardized methods. This paper presents the results obtained which represent 87% of Italian agriculturally used area and covers products such as cereals, industrial and vegetable crops, forage crops and fruit tree crops. Analyses were also carried out on cattle, sheep and goat breeding farms. For each sector, the analysis was broken down into direct energy use (fuel and electricity) and indirect energy incorporated in the various means of production. Consumption per hectare, specific consumption per unit at output and the employment of labour were calculated. The results obtained are comparable to those contained in the international literature. Total energy consumption proved to be 13Mt of oil equivalent per year, 35% of which is represented by direct energy. The employment of human labour corresponds to 1.4M full-time working units, one full-time working unit being equal to 1900 h/a. 1. Introduction
Italy consumes approximately
140 Mt of oil-equivalent (Mtoe) per year and over 80% are met by foreign sources. Official national statistics pay very little attention to the energy consumption of agriculture, for a number of reasons. First, only fuel purchased by farmers at subsidized prices is considered when analysing fuel consumption for agricultural and animal production. Second, diesel oil and gasoline purchased directly by farmers from normal service stations are excluded and classified in the transport sector. Third, only the percentage of total electricity consumption related to connections for agricultural uses is included in the agricultural sector; this involves approximately 400,000 farms with a total consumption of 1.8 MWh/a but there are, in fact, 2.2 M farms and their electrical usage for agriculture is attributed to household consumption. Fourthly, all indirect energy consumption (i.e., the energy embodied in the technical means needed for agricultural production, namely fertilizers, pesticides, seeds and machinery) is included in the “industrial” sector. After a preliminary analysis’ carried out by the CNR (Italian National Research Council) in 1980 and an in-depth document* prepared by the CNEL (National Council on Economy and Labour) in 1982 (in which the energy consumption of the whole agricultural-food production system was thoroughly examined for the first time in Italy), a wide-ranging3 study was considered to be necessary to provide further clarification of the subject. This investigation was part of the 5-year CNR National Energy Research Programme. of the country’s energy requirements
2. Scope of study The study
was carried
research institutes
out over
the course
of 4 years
located in various parts of Italy. 111
with
the cooperation
The first step was definition
of 13
of a
112
USE
OF
ENERGY
AND
LABOUR
IN
ITALIAN
AGRICULTURE
common operative methodology based on the evaluation of gross energy requirements identified 15 years ago by a working group sponsored by the International Federation of According to this method, calculations Institutes for Advanced Studies in Stockholm.W should not include any renewable energies, such as solar energy, whose availability does not require any conventional sources.
Primary
energy
incorporated means
Table 1 (average) of production
Means
MJ/kg MJ/kg MJ/kg manure
MJ/kg
Pesticides & herbicides* Pesticides Herbicides Insecticides
.MJ/kg
Seeds & propagation materials Cereals and forage Potatoes Sugarbeet Vegetables (leguminous) Vegetables (not leguminous) Bulbs Seedlings
MJ/kg MJ/kg MJ/kg MJ/kg MJ/kg
Feedstuff Forage Maize for ensiling Concentrate Milk powder Straw
MJ/kg MJ/kg MJ/kg
Lubricants
MJ/kg
MJ/unit MJ/unit
8-10 1.2-1.5 12-16 100-120 0.5
concrete
a
9-10
MJ/kg MJ/kg
a a
8-10 6-8
MJ/m’ MJ/m’ MJ/m’
a a a
32-38 2.5-3.0 70-80
MJ/kg
MJ/kg MJ/kg MJ/kg
MJ/kg product.
SO-85
MJ/kg
MJ/kg MJ/kg
* Per kg of commercial
9-12 2.2-2.6 2.0-2.4 18-22 47-55 I.5 0.2
MJ/kg MJ/kg
Buildings Cowsheds Hedges Greenhouses Materials Masonry Concrete Reinforced Wood Wire Plastics Twine
50-60 x5-95 50-55
MJ/kg MJ/kg
Tractors & agricultural machines Tractors and self-propelled machines Stationary equipment Agric. machinery & implements
technical
73-75 13-14 9-10 IO 0.4
MJ/kg
pzo,
main
Primary energy
Units
Fertilizers N K,O Mg Rotted
in the
2.0-2.2 1.1-1.3 2.8-3.0 2.4-2.6 40-45 100-130 8-12
G.
113
PELLIZZI
A preliminary decision was made also as to the value to be attributed to the energy incorporated in technical means of production; these values were calculated on the basis of the consumption of conventional energy sources in the various production processes (Table 1).7 Consequently, in the case of all mineral fuels, the added costs represented by the energy needed for their production (up to the “refinery gates”) were also taken into consideration. In the case of electric energy, moreover, the equivalent energy in terms of primary sources was calculated on the basis of the average efficiency for production and distribution of the Italian electric grid. This means that 1 t of diesel-oil corresponds to 1.2 toe; 1 t of gasoline to 1.32 toe; 1 t of LPG to 1.4 toe and 1 MWh of electricity to 0.25 toe, where 1 toe = 42 GJ. Furthermore, it was decided not to apply any energy value to human labour, since consumption connected with the daily requirements of farmers and farmworkers (as well as those of the population in general) are classified as “domestic use” and “transport” in the national statistics. Therefore, man-hours registered were reported as such without any transformation into energy units. Over 40 main crops were studied in the field for 4 consecutive years on 200 farms located in different parts of Italy. The various farms have been chosen on the basis of their representativeness (size, production system, crop rotation adopted, income and mechanization levels, labour productivity etc.) of the different areas considered, subdivided according the various pedo-climatic conditions. These crops cover approximately 13.5 Mha of agriculturally used area (1987 data), 34% of which was cultivated with cereals, 31% with temporary and permanent grassland, 22% with fruit tree crops and grapes and the remaining 13% with industrial and vegetable crops. Therefore, the analysis concerned 87% of total agriculturally used land, the remaining 13% being cultivated with minor crops. Land used for grazing (3.8 Mha) and forests (6.7 Mha) was excluded. The analysis was completed by an investigation into dairy and beef cattle, sheep and goat farms. The different farms were chosen with the same criteria above mentioned for crops. In the final calculations the energy spent for forages has been included in the energy consumption requested for animal production.
3. Results
obtained
The results obtained on the most important crops are summarized in Tables 2 to 6 and are shown by type of production. In the various tables the maximum and minimum energy consumption figures registered in the different conditions studied have been reported. To calculate the total energy consumption of the various production sectors we considered the registered figures (per ha and/or per kg of output) in the different farms and multiplied them by the areas (or the number of animal heads) where the same production processes are used and similar yields obtained.
3.1. Cereals Unit consumption (Table 2) varies from 4 to 8 MJ/kg of harvested product, which corresponds to a consumption per unit of cultivated area between 12 and 54 GJ/ha. If the extent of the area planted with various species is taken into account (totaling just over 4.5 Mha), then total consumption turns out to be 3.2 Mtoe/a. Approximately half of this figure is represented by the production of winter-type grains and 30% by maize. The energy consumed by straw collection (a total of approximately O-3 toe/a) must also be added to this value.
114
USE
OF
ENERGY
Table Energy
consumption
AND
LABOUR
IN
ITALIAN
AGRICULTURE
2
for the cultivation
of cereals Species
l/nil
of Consumpfion Direct Indirect
measure
energy energy
Machinery Lubricants Fertilizers Pesticides Seeds Buildings Consumable
materials
Total consumption Specific consumption Human labour * Including 1.5-2 MJ/kg,
Durum wheor
sofl wheat und burley
Maize
Rice
% 5%
30-W X-70
20-35 65-80
45-W* 40-55
27-35’ G-73
% 8 % % % o/o o/o
3-7 l-2 2X-54 1-3 6-11 1-2 0.5 I
3-7 1-2 36-63 l-2 4-10 l-2 0.5 I
4-10 l-2 30-40 2-3 l-2 l-3 0.5 1
4-7 1-2 35-40 II-16 24 2-3 Y.5-I
12-20 4-x 16-22
12-23 3.5-4.5 19-30
20-54 4.2-8.4 13-40
30-34 5.4-X.3 27-34
GJ/ha MJ/kg h/ha
drying. The harvesting of which corresponds to 3.5-4.0
wheat MJ/ha
straw results in consumption with 5 h/ha of labour.
figures
of
On average, direct energy consumptions (fuels and electricity) represent 35% of the total and thus correspond to just under 1.4 Mtoe/a. These values are lower in the case of wheat and wheat-like crops (approximately 30% of the total) and higher for maize and rice mainly due to drying requirements. The amount of energy required by fertilizers is also high (averaging 40%), while pesticides and herbicides have a marginal value (in purely energy terms), which does not exceed 3% except in the case of rice, where it represents 11 to 16% of the total. The amount of energy that may be attributed to seeds is also high in the case of winter sown cereals and rice. It represents respectively between 4 and 11% of the total consumption as far as wheat is concerned and 24% as for rice. Finally, the amount of human labour employed does not exceed 40 h/ha and frequently falls below 20 h/ha. 3.2. Industrial
and vegetable crops
This group of crops (Table 3) is extremely heterogeneous, and therefore the main species are discussed separately below. The energy required for the production of sugarbeet, which is cultivated on just over 300,000 ha, varies widely depending on the location considered. However, if we assume an average value of 50 GJ/ha, total consumption turns out to be 0.37 Mtoe/a, approximately half of which is represented by direct energy. Fertilizers represents about 75% of indirect consumption. The significant differences observed in various situations seem mainly to be owing to the physical and structural properties of the soil considered. Indeed, for clay soils, direct consumption is almost double that of loamy soils. The amount of labour required varies from 25 to 105 h/ha in the different geographical areas, depending on the type of mechanization adopted as well as on the irrigation practices required in southern areas. The energy required for the production of potatoes, which are cultivated on just over 130,000 ha, is approximately 35 GJ/ha, which corresponds to a total consumption of
G.
115
PELLIZZI
Table Energy
consumption
for the cultivation
3 of some industrial
and vegetable
crops
Species i/nil of memsure
Comwnption
Sugar beer
Poruioes
Soybeans
Sunflowers
Totnoloes
33-46 54-67
JO-63 37-60
45-55 45-55
1 .s-3.5 1.5-3.5 40-46 2.5-4.3 ws- I .2 o.s- I ws- 1
5-12 1.5-3.5 20-30 2-g 0.1-0.6 0.X-1.2 0.5-0.9
3.5-5 2-26 20-35 l-l.5 x-10 0.5-1.2 0.3-0.7
IX-23 5.6-10 25-55
34-50 0~6-0~9 167-997*
30-35 4-15 30-Ytl
Direct energy energy Indirect
% o/r
36-59 41-64
30-35 65-70
U-70 30-56
Machinery Lubricants Fertilizers Pesticides Seeds Buildings Consumable
% % %I ?4 % 74 o/u
2-6 l-l.5 32-49 I .5-4 l-1.2 l-l.2 0.5-0.7
IO-12 I-S 25-40 l-I.5 12-17 0~5-1 0.5- 1
2.5-6.5 1.5-3.7 IS-35 0-5-5.6 s-15 0.5-1.2 0.5-I
35-70 0.7-1.9 40- I05
32-3X WY- I.5 ho-430*
15-30 4-1s 13-43
materials
Total consumption Specific consumption Human labour * Manual
GJ/ha MJ/kg h/ha
Kidney and green beam
Peas 38-44 56-62 6-7 2-2.5 30-35 I .5-2.5 12-15 0.5-l .2 0.2-0.6 20-26 4-5 20-25
harvesting.
110,000 toe/a. Fuel and fertilizers each represent 30-35% of this figure. In addition, seeds and machinery each contribute lo-17% to the total. However, manual harvesting or single-operation machines are still used in many areas, as confirmed by the intensive employment of labour. Therefore, an increase in direct energy consumption due to the development of mechanization should be expected in the future. On fully mechanized farms, in fact, direct consumption ranges from 240 to 280 kg/ha of oil equivalent while labour required drops to a minimum of 25 h/ha. Average unit consumption in the case of soybeans, which are cultivated on just under 480,000 ha, is of the order of 22 GJ/ha; this figure is approximately equally divided between indirect and direct energy. This results in a total consumption of 250,000 toe/a in round figures. About half of all direct consumption is related to irrigation, which means that in areas in which this is not strictly necessary there is a significant drop in the total energy requirement. Once again, fertilizers represent the highest percentage of indirect consumption, while values vary widely as far as consumption related to pesticides is concerned (from 0.5 to 5.6%). Seeds represent up to 16% of total consumption. Figures on labour range from 13 to 43 h/ha with considerable differences among the various situations; this is partially due to the irrigation practices. Average consumption in the case of sunflowers, which cover almost 110,000 ha, is 20 GJ/ha and corresponds to just under 53,000 toe/a; approximately 40% of this is represented by fuel. The most important form of indirect consumption concerns fertilizers, which represent an average of 45% of the total. Finally, this crop requires a relatively limited amount of labour, that is, about 30 h/ha. Tomatoes also cover just over 110,000 ha and require (in the case of varieties grown for industry purposes) widely divergent amounts of energy depending on the cultivation method employed. In fact, open-field crops consume 40-50 GJ/ha (corresponding to just over 110,000 toe/a); this figure is approximately equally divided between direct and indirect energy. In cases in which plastic mulching is used, consumption increases to over 240 GJ/ha and 3.5 MJ/kg of harvested product. Figures on the amount of labour required range from averages of 160-170 h/a, where mechanical harvesting is employed, to almost 1000 h/ha in the case of manual harvesting. Finally, total energy consumption in the case of beans (kidney and green) and peas,
116
USE
OF
ENERGY
AND
LABOUR
IN
ITALIAN
AGRICULTURE
which cover approximately 70,000 ha, is 50,000 toe/a with specific consumption between 4 and 15 MJ/kg. When mechanical harvesting is used on these crops, labour does not exceed 30 h/ha. 3.3. Fruit tree crops Values concerning this group of crops (Table 4) show a relative homogeneity of energy consumption, which totals about 40 GJ/ha. This figure corresponds to 2.9 Mtoe/a (50% of which is represented by fuels) over a total cultivated area of approximately, 3 Mha. A considerable amount of energy is used in fertilizers, with maximum values reached in the case of citrus fruit and minima in that of fleshy fruit. Pesticides also represent a high percentage of indirect energy in the case of fleshy fruit and grapes. When manual harvesting is employed, figures on labour exceed 1000 h/ha (as in the case of lemons). This figure drops to 200-230 h/ha when appropriate grape-harvesting equipment is used. 3.4. Forage crops Italian forage production takes place on approximately 4.2 Mha of temporary and permanent grassland. The energy consumption connected with these crops (Table 5) averages between 15 and 20 GJ/ha. This means that total consumption is in the order of 1.2 Mtoe/a; the major portion of this figure is represented by mechanization (including irrigation and artificial drying) and fertilizers. Permanent grassland requiring no more than 1.5 MJ/kg of fresh grass, consume the least amount of energy, while temporary meadows consume approximately double. In the case of hay, consumption reaches 3.5 MJ/kg. This value increases to 4.4 MJ/kg when two-stage drying with hot air is employed; however, this method raises yields per hectare and improves forage quality. Obviously, significant differences are met between irrigated and non-irrigated areas and, in the former case, with regard to the irrigation system adopted. On average, labour is employed for 30 h/ha, with minima of 14-15 h/ha. With regard to maize for ensiling, an average energy consumption of 35 GJ/ha results corresponding to less than 1 MJ/kg of harvested product because of high yields. If these
Table Energy
consumption
4 for fruit
tree crops Species
Unil
of Consumprion Direct Indirect
measure
energy energy
Machinery Lubricants Fertilizers Pesticides Buildings Consumable
materials
Total consumption Specific consumption Human labour * Manual harvesting; t The highest values
Fleshy Cirrus
Grapes
Olives
.-
!““L.
_
NuL
% %
25-34 66-75
35-w SO-65
JO-60 40-60
40-50 40-60
25-35 65-75
% % % % %
1.7-2 0.5-1.2 45-73 2-3 1.5-2
6-12 1-2 30-40 6-9 l-1.5
6-12 1.2-1.5 20-30 l-2 0.1-0.5
4-12 l-l.5 g-12 12-25 l-3
7-15 0.X-1.4 40-55 1-3 -
%
14-15 -.--~~~.
S-10
2-5 _-~~~
4-6
2S-45.t 1.5-2.9 230-350
30-50 4.5-6 350-470
38-43 1.2-2 300-700
W/ha MJ/kg h/ha higher values are observed
40-47 1.2-1.5 490- 1300* apply in the case in southern areas.
of lemons.
l-2 20-32 6-10 100-130
G.
117
PELLIZZI Table Energy
consumption
for
the
Unir Of measure Direct Indirect Machinery Lubricants Fertilizers Pesticides Seeds Buildings Consumable
materials
Total consumption Specific consumption Human labour * Up t Up
of grass
GJ/ha h/ha
and
forage
cereals
Maize
for
ensiling
42-50 50-58
SO-70 30-50
35-so* SO-65
25-45 55-75
5-6 I .5-2.5 30-45 -
12-15 3-4 X-12 -
5-u 2-4 35-50 -
I .5-4 l-2 I .5-2
l-3 1-3
3-4 2-3 2-4
4-6.5 1.5-3 35-45 l-3 0..5- 1 1.5-3 I-1.5
20-25 I .2-3 14-20
MJ/kg
land
Species Hay from Pcrmanenr iemporary grassland grassland
Temporary grassland
% %
energy energy
5
cultivation
7-17 0.3-1.5 30-40
1X-27 2-3.5t 15-23
25-45 0.5-0.9 25-40
to 75% in the case of two-stage, artificial hay-making; to 4.2 MJ/kg in the case of two-stage hay-making.
values are extrapolated to include all of the 1.4 Mha cultivated, then total consumption turns out to 1.2 Mtoe/a. The amount of labour required varies from 25 to 40 h/ha. 3.5. Animal
breeding
In this case (Table 6), the energy analysis, which, as mentioned above, includes consumption related to forage production and the majority of the straw harvested, has been divided up-as far as cattle, sheep and goats are concerned-into milk and meat production.* In the former case, average consumption related to milk cattle is 10 GJ/t produced. Taking into account that cow milk production is in the order of 8.7 Mt/a, then total consumption turns out to be 2.1 Mtoe/a, only about 10% of which is represented by Table Energy
consumption
for
6 animal
production
Species
Consumption Direct Indirect
~__~
~--
Unir of measure
energy energy
Milk cattle
Milk sheep
Beef carrle
“/a %
7-15 85-93
6-10 90-94
30-40 60-70
Machinery Lubricants Feed Forage Bedding
% % % % %
1.4-3 0.3-0.5 SO-60 IS-20 0.7- 1
0.5-2 0.3-0.4 12-18 W-75
6-8 1-3 50-60
Buildings
%
5-11 ~~ -..-
l-2
3-5
20-25 20-25 25-30
60-70 6-7 12-18
-~~-~
Total consumption Specific consumption Human labour * per
unit
weight
GJ/t* MJ/kg* h/t* of milk
or beef
10-12 7-13 5-20
-
118
USE
OF
ENEKGY
AND
LABOUK
IN
ITALIAN
AGRICULTURE
direct energy. Of the other energy users involved, an average of 55% is attributable to concentrated feed and 17% to forage. The percentage represented by buildings is also high. Figures on the amount of labour employed vary from a minimum of 5 h/t (in the case of large, highly mechanized herds) to a maximum of 20 h/t of milk produced. In the case of sheep and goat milk, average consumption is approximately 22 GJ/t of product, which corresponds to O-9 Mtoe/a; the main portion of this figure is represented by forage. The amount of labour required ranges from 25 to 30 h/t of product. Finally, in terms of beef production, which totals 900,000 t/a. consumption is 6-5 GJ/t, which corresponds to 140,000 toe/a. In this case, direct energy consumptions represent 35% of the total, while feed covers 55%. The average amount of labour required is 15 h/t. In addition, the yearly production of lamb and goat meat (70,000 t/a), pork (1.2 Mt), horse meat (54,000 Mt), and fowl (1 Mt/a), as well as eggs (11 billion), must also be taken into consideration. If we adopt data from the literature regarding these products3,a it is possible to estimate an additional energy consumption of approximately 2 Mtoe/a. In conclusion, the total consumption related to animal production reaches 5.1 Mtoe/a in round figures. 4. Discussion
The analyses carried out have made it possible to calculate total energy consumption with regard to the agricultural and animal products considered of approximately 12.2 Mtoe/a, about 35% of which is represented by direct energy (4.3 Mtoe). If we recall that the crops considered represent 87% of the total agricultural used area, and if we assume that a cautious estimate of the energy consumption of the remaining 13% is 12GJ/ha, then another 800,000 toe should be added to the figure of 12.2 Mtoe. This average value used of 12 GJ/ha takes into account the various crops cultivated and the figures registered in analyses carried out previously.3 This means a total consumption quite close to 13 Mtoe, 4.5-4.6 Mtoe of which is represented by direct energy. The CNR’s National Research Project on Agricultural Mechanization’ evaluated direct energy consumption (including that of farm dwellings) as 5.07 Mtoe/a. Meanwhile, the Table Comparison
among
the
results Pimentel
obtained and Ilalian analyses MJ/kg
Wheat Maize Rice Potatoes Sugarbeet Kidney & green Peas Hay Maize for ensiling Citrus Grapes Fleshy fruit * per
kg of dry
beans
matter.
3.S4.5 4.2-8.4 5.4-8.3 0.9-1.5 0.7-1.9 4-15 4-s 2-3.5 0.5-0.9 1.2-1.5 1.5-2.9 I .2-2.0
7 and Slesser
the
figures
Pimenrel
MJlkg 3-32 3.S 18.5 10.5-12.0 I .3-3. I 10.9-13.9* 8.4’ 1.2-4.x 2.1-3.9* 0.7-1.2 3.0- 15.5 2.0-3.2
provided
Slesser.
MJlkg 0.9- 12 s-11 0.2-12 0.2-3.1 0.5-1.3 0.2-8.3 -
by
G.
119
PELLIZZI
CNEL’ has defined total consumption as 13.5 Mtoe, 63% of which is represented by the energy incorporated in various means of production. Therefore, the analyses carried out confirm these values and indicate that agriculture (i.e., every operation up to the “farm gates”) represents approximately 9% of total energy consumption in Italy. Specific consumptions acquired are comparable to those reported by Pimentel’ and Slesser lo (Table 7). It has to be taken into consideration, that the above papers consider an ample spectrum of conditions in Europe and outside. Finally, it is also interesting to note that, according to this investigation, the total amount of labour employed in the agricultural sector is approximately 1.4 m full-time working units (1 FTWU corresponds to 1,900 h/a). 5. Conclusions The results obtained from the analyses carried out confirm the energy consumption values estimated during previous surveys carried out on a nationwide scale. They are also comparable with the figures shown in international literature. However, as a result of the survey carried out it was possible for the first time to define the consumptions relating to individual crop and livestock products as well as the different amounts of energy consumed as a result of the use of various inputs. An assessmentwas also made of the labour employed in the various crop and livestock production systems, from which it was possible to work out an overall assessment expressed in full-time working units. References L.; Castelli, G.; Pellizzi, G.; Sangiorgi, F. Agricoltura e crisi energetica (Agriculture and energy crisis)-CNR, Progetto Finalizzato Meccanizzazione Agricola. Quaderno n. 18, 1981:46 pp * CNEL, Osservazioni e proposte su Agricoltura ed Energia (Remarks and proposals on Agriculture and Energy)-Rome, 1982,2: 15-78. ’ Bodria,
3 Biondi, P.; Panaro, V.; Pellizzi, G. Le richieste di energia del sistema agricolo italiano (The energy requirements of the Italian agricultural system)-Progetto Finalizzato Energetica,
CNR-ENEA, LB-20. 1989,389 pp. ’ Biondi, P.; Farina, G.; Panaro, V. L’analisi energetica in agricoltura (Energy analysis in agriculture)-Rivista di Ingegneria Agraria 1987, 4: 205-219. 5 IFIAS, Energy analysis-Workshop report n. 6. Stockolm. 1974,46 pp. ’ IFIAS, Energy analysisand economics-Workshop report n. 9, Stockolm, 1975,52 pp. ’ Jarach, M. Sui valori di equivalenza energetica per I’analisi e il bilancio energetic0 in agricoltura (On the conversion factors for the energy analysis and balance in agriculture)-Rivista di Ingegneria Agraria 1985, 2: 102-112. * Pellizzi, G. Meccanica e Meccanizzazione Agricola (Agricultural Machinery and Mechanization)--Edagricole, 1987, 482 pp. ’ Pimentel, D. Handbook of Energy Utilization in Agriculture-CRC Press, 1980: 342 pp. ” Slesser, M.; Wallace, I. Energy Consumption per Tonne of Competing Agricultural Products Available to the E.C.-CEC, Inf. on Agriculture, n”85, 1982: 168 pp.