Energy conservation in Agriculture
Very high farm operating and capital cost in recent years have made efficient farm management extremely important. To the farmers, efficient management of farms is to find ways for energy conservation in agriculture to maximize their net returns so that they can operate within existing economic constraints.
To obtain higher farm profits, returns should be increased or costs should be decreased. Now a days there is an increasing trends in commercialization and diversification towards high-value crops for energy conservation in agriculture. On the input side, there is substantial increase in the use of modern inputs and farm mechanization, including small and marginal farms.
These developments have significant implications for energy use in agriculture. Modern inputs and mechanization require more commercial energy. Demand for energy in non agricultural sectors is also increasing day by day. Rising trend in oil prices have directed people to look for alternative sources of energy and energy-efficient technologies.
Expanding acreage is one way to increase total profit, but land constraints, less cost benefit ratio and market conditions often prohibit this option. Improved varieties, fertilization, irrigation and management have substantially increased production, but these changes occur more slowly.
Thus, there is increasing demand for higher productivity and higher energy input which ultimately increases the cost of energy. Therefore, reducing costs without changing any other production parameters is an attractive option to combat with the situation which can help for energy conservation in agriculture.
Energy use pattern in Indian agriculture
India with cultivable land area of 142 M ha and abundant natural resources has a conducive environment for agricultural production. The structure of energy-use in Indian agriculture has changed substantially, with a significant shift from the animal and human power towards machines, electricity and diesel.
Energy used in agriculture can be divided in two categories, viz. direct use of energy for pumping and mechanization (tractors, power tiller, etc.) and indirect use of energy in the form of fertilizers and pesticides. The total commercial energy input in Indian agriculture has increased from 425.4 × 109 Mega Joules in 1980-81 to 2592.8 × 109 Mega Joules in 2006-07.
This increase in energy consumption in Indian agriculture is due to rapid expansion of tube-well irrigation in the Indo-Gangetic Plains and increased consumption of phosphatic and potassium fertilizers.
This shift in energy consumption, coupled with increasing commercialization and diversification towards high-value crops, will require more commercial energy.
Therefore, there is an urgent need for energy conservation in agriculture by developing energy savings technologies for agricultural production.
Energy use pattern of major crops
Energy use patterns of different crops differ with material inputs such as seeds, fertilizers, manures, insecticides and mechanical energy along with human and bullock labor hours used and extent of farm power operations, irrigation used in the crop production process.
Considerable variations in the form and extent of energy use and its efficiency exist in the production of major crops. The national weighted average scenario of major crops covering 71.3 % of gross cropped area in the country indicates that among major food grain crops, wheat and paddy are high energy consumers in majority of the areas.
Rice produces lower dietary energy-output per unit of external energy-input as compared to wheat as rice uses more energy to generate the same calorie energy than of wheat. This implies that wheat is a more energy-efficient crop as compared to rice.
The pulse crops consume <50% of that for wheat and paddy. The oilseed crops also consume lower energy in the range of 6832-8051 MJ/ha. Cash crop like sugarcane and potato with high fertilizer and irrigation energy use are high- energy consumers.
Due to high crop productivity, cash crops like sugarcane and potato have high energy productivity of 1.039 kg/MJ and 0.495 kg/MJ respectively. The food grains have higher energy productivities than oil seeds and pulses (De, 2006). The crop productivities of major crops in India are still lower than some of the Asian countries. Increases in crop productivity in India, driven by future food demand, would require higher energy investment with present cultivation practices.
Energy conservation through tillage options
To feed the over swollen population of India in future, more food grain production is needed with existing available energy and resources. Therefore, we need to find out the ways of conserving energy. Reducing tillage operations, efficient management of crop residues, irrigations, nutrients, pesticides and all other inputs will help to conserve energy in agriculture.
As tillage is an important energy consuming operation in agriculture, reducing its intensity and frequency will help in reduction of energy use a lot. Therefore different options of reduced tillage operations to save energy are discussed here.
The aim of tillage is to prepare the soil environment favourable to plant growth. It consists of all operations for seed sowing which improves soil, and environmental conditions for seed germination to crop growth. Minimum tillage, zero tillage or conservation tillage etc are the better options to conserve energy in agricultural production.
Through its emphasis on reducing inputs, conservation tillage saves significant energy costs without jeopardizing productivity. Land preparation prior to planting generally requires significant energy inputs, resulting in high operating costs.
New techniques to reduce the cost of preparing land could be beneficial to growers. Thus reducing tillage operations is an important option of energy conservation in agriculture.
Generally, there are two types of tillage systems i.e. conventional, and conservation tillage system. Under conventional tillage practices, residues are incorporated into the soil by extensive tillage. It is of two types i.e. mechanized, and traditional systems.
Traditional tillage system is carried out by manual labour using native tools. In mechanized system, mechanical soil manipulation of an entire field is done by ploughing through one or more harrowing. According to the Conservation Tillage Information Centre (CTIC), conservation tillage eliminates conventional tillage operations that invert the soil, and burry crop residue.
No-tillage, minimum tillage, reduced tillage, and mulch tillage are synonymous terms for conservation tillage. Below are the different types of tillage in conservation tillage:
No-tillage: It is also known as zero tillage. In this system, soil, and surface residues are disturbed at minimal rate. The surface residues play an important role in soil and water conservation. It reduces all pre-planting mechanical seed sowing preparation except to open a narrow (2-3 cm wide) strip or making small hole in the ground for seed sowing to ensure ample seed soil contact.
Mulch tillage: It is based on the principle of reasonable least soil disturbance, and leaving maximum of crop residue on the soil surface. This can provide faster germination, and growth as well as good yield.
Reduced or minimum tillage: In this system, minimum 30% surface is covered with crop residue. The number of tillage is reduced than conventional tillage system.
Indo Gangetic plains of India, Bangladesh and Pakistan having 1.9 m ha area under zero tillage. There are several case studies to prove the importance of zero tillage or reduced tillage in conservation of energy in agriculture.
Behera and Sharma (2011) calculated that under recommended fertilizer application mustard crop required highest energy of 11,800 MJ followed by cow pea (around 85% of mustard) and green gram (around 50% of mustard). They found that total energy requirement of mustard-green gram cropping system under conventional tillage was 29,363 MJ, while it was 25,138 MJ for zero tillage, thus an energy saving of around 15-20% was recorded in different crops under zero tillage to conventional tillage.
This energy saving was due to reduction in fuel consumption, machinery costs and human labour. Singh and Singh (2006) tested the Pantnagar zero till seed cum fertilizer drill in field condition for lentil cultivation. Net profit of Rs. 14710 per ha was found in zero till drill as compared to Rs. 3871 per ha in conventional method. Thus output input ratio was also higher in case of zero tillage compared to the conventional tillage.
Kumar et al. (2013) investigated the effect of five wheat establishment methods viz. conventional tillage, reduced-tillage, rotavator tillage, raised bed planting and zero-tillage for their energy and economic efficiency in a Typic Ustochrept alluvial sandy loam soil in the IGP. They observed the energy requirement was 13% lower in zero-tillage than conventional tillage., 10% lower than rotavator tillage.
Due to lower energy requirement in zero and reduced tillage, their energy output was higher in wheat crop. In zero and reduced tillage, the energy output was 5% and 3% higher than conventional, respectively. The energy use efficiency was highest in zero tillage (7.42) followed by reduced-tillage (7.12), rotavator tillage (7.04) and least in conventional tillage. Abrol et al. (2005) did an experiment with rice establishment methods viz. zero tillage direct seeded and puddled transplanted.
Hours required per irrigation by 5 H.P was 20 in case of zero tillage direct seeded and 28 for puddled transplanted and total diesel requirement were 100 and 364 litres/ha respectively. Thus diesel saving of 264 litres/ha was there for zero tillage direct seeded. Total no. of irrigation applied for zero tillage and puddled transplanted were 5 and 13 respectively.
So 72 % water saving was there in case of zero tillage as compared to puddled transplanted. Low intensity tillage favours consolidation of soil through better structure, infiltration and pore distribution. This imparts erosion resistance. Zero or reduced tillage operations also reduce water required for irrigation and protect the soil by reducing run off losses (Bhardwaj, 2013; Busari et al. 2015).
Yield increases have also been observed under zero or reduced tillage operations (Busari and Salako, 2013). Conservation tillage operations can be adopted even in exhaustive energy consuming crops like rice, wheat, sugarcane etc as these are extensively grown in India.
Continually escalating fuel prices compelling farmers to find ways to conserve fuel in order to reduce costs of crop production. So there is an opportunity for conservation tillage, including no-till direct drilling systems in various cropping systems for increasing input use efficiency. Reducing tillage system will directly help in reducing the cost of crop production.
However, for widespread adoption of conservation tillage still more research is needed. Farmers’ participatory evaluation of this system is also required for direct benefit and improvement of livelihood of rural population. Also policies should be there to encourage the adoption of this system.
Mandira Barman, V.K. Sharma, S. K. Singhal, Ruma Das, Shrila Das and Sunanda Biswas
Division of Soil Science and Agricultural Chemistry, ICAR-Indian Agricultural Research Institute, New Delhi-110 012
Contact E-mail: [email protected]
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Abrol, I. P., Gupta, R. and Malik R. K. (2005). (Eds). Conservation agriculture-State and prospects,CASA, New Delhi. P. 154
Bhardwaj, R. L. (2013). Effect of mulching on crop production under rainfed condition – a review. Agricultural Reviews, 34: 188 – 197.
Behera U. K. and Sharma A. R. (2011). Effect of conservation tillage on performance of greengram – mustard – cowpea cropping system. Journal of Soilless and water Conservation, 10: 233-236
Busari, M. A., Kukal, S. S., Kaur, A., Bhatt, R. and Dulazi, A. A. (2015). Conservation tillage impacts on soil, crop and the environment. International Soil and Water Conservation Research, 3:119-129.
Busari, M. A. and Salako, F. K. (2013). Effect of tillage, poultry manure and NPK fertilizer on soil chemical properties and maize yield on an Alfisol at Abeokuta, South-western Nigeria. Nigerian journal of Soil Science. 23: 206-218.
Kumar, V., Saharawat, Y. S., Gathalac, M. K., Jat, A. S., Singha, S. K., Chaudhary, N. and Jat, M. L. (2013). Effect of different tillage and seeding methods on energy use efficiency and productivity of wheat in the Indo-Gangetic Plains. Field Crop Research, 142: 1-8.
Singh, R. D. and Singh, P. M. (2006). Performance of zero till drill for lentil cultivation at farmer’s field. Journal of Agricultural Engineering, 43:70-73.