Authors: ANURAG PATEL1, R.C. SINGH2, DUSHYANT SINGH2 AND PRABHAKAR SHUKLA2
1Vaugh School of Agricultural Engineering and Technology, SHUATS, Allahabad (U.P.) - 211007
2ICAR-Central Institute of Agricultural Engineering, Bhopal (M.P.) - 462038
CA is a system in integrated management of soil, water and biological resources combined with external inputs. It is based on agricultural crop production that achieve acceptable profits together with high and sustained production levels while conserving the environment with resource saving. Interventions such as mechanical soil tillage are reduced to an absolute minimum and the use of external inputs such as agrochemicals and nutrients of mineral or organic origin are applied at an optimum level and in a way and quantity that does not interfere with disrupt the biological process. The effect of direct seeding/planting has been found to be advantageous in terms of improved traffic ability, decreased soil compaction in long run and reduced soil erosion due to wind and water. It also leads to decreased water evaporation and increased availability water in to the soil.
Objectives and Principles of CA
Its objectives are to improve agriculture production by adopting economically, ecologically and socially sustainable methods with aims to conserve, improve and make more efficient use of natural resources. It contributes to environmental conservation as well as to enhanced and sustained agricultural production for farmers.
i) Ploughing or hoeing turns the soil over. It destroys the natural soil structure, and creating a hard layer that roots cannot push through.
ii) Conservation agriculture breaks through the hard layer, letting water to seep into the soil and allowing roots to grow down.
iii) Ploughing exposes the soil to the rain and sun. The soil is washed away easily by heavy rain, causing erosion. Dongas are eating their way into Lesotho’s precious soil like hungry hyenas.
iv) CA protects the soil surface and prevents erosion. With conservation agriculture, dongas can be a thing of the past.
v) Planting the same crop season after season allows pests, diseases and weeds to multiply. That means lower crop yields and a monotonous diet.
vi) CA mixes and rotates crops to break the life cycle of pests, diseases and weeds. The result: higher yields and a more varied diet.
1. Building up the soil organic matter also retains nutrients and improves the micro-flora in the soil, a vital component of living soil. The soil is richer and darker, and there are more earth worms, beetles and other creatures that help keep the soil fertile.
2. Soil organic matter can hold many times its weight in water, therefore building up the organic matter in the soil results in greater water retention.
3. When soil organic matter is built up through Conservation Agriculture, applied fertilizers work better.
4. Different crops have different root structures– some have deep tap roots and others have fibrous roots at the surface. Through crop rotation, organic matter is placed in different soil strata, thereby making the soil more fertile.
5. It allows rainwater to seep deep into the soil, and then keeps it there so crops can use it.
6. It improves the soil structure: it breaks down the hardpan and it makes the soil looser, making it easier for roots, water and air to penetrate the soil.
Tillage is an important and primary tool for conservation of the land. As per definition, its primary purpose is to provide a favorable soil environment for the plant growth, which is indirectly related to the soil conservation. The effect of tillage on soil erosion is the function of its several effects on soil such as aggregation surface sealing infiltration and resistant to erosion destruction of soil structure either by excessive tillage or tillage operations at improper soil moisture condition tends to increase the soil credibility, causing significant soil loss. Important types of soil tillage practices are described below;
Minimum tillage: The Minimum tillage practices may progress from reducing the number of tillage passes to stopping tillage completely (zero tillage). The technique has found some practitioners in India, especially in Punjab and other northern states for the wheat crop. It is becoming popular because of the direct economic benefits it provides farmers. With less tilling, farmers save on machinery use, fuel, labour and their own time. The cover of crop residue helps prevent soil erosion by water and air, thus conserving valuable topsoil.
Happy seeder: The happy seeder technology offers a solution to the problem of direct drilling into heavy stubbles, enabling the stubble to be retained on the surface as mulch. The equipment is the combination of straw handling unit and sowing unit. It is used for sowing operation in combine-harvested field in a single pass while retaining the crop residue as surface mulch. The unit is compact, light weight and tractor mounted capable of managing rice stubbles and loose straw in a strip just in front of each furrow opener.
Roto till drill: Above the 35 hp tractor operated equipment and is used for sowing seeds into the soil directly opened with the help of rotavator attached with the machine, in a single operation in the stubble fields. The machine performs the tillage operation and directly place seed and fertilizer in the soil opening in the stubble fields of paddy and maize. Cost reduction by time and energy saving and optimization of environmental health by reducing soil compaction are the main highlighted features of this machine field and thus increases the yield.
Slit till drill: The 45-50 hp tractor operated equipment and is used for sowing seeds into the slits opened with the help of rotary slit disc, attached in front of the furrow openers of machine, in a single operation in the stubble fields. The machines prepare a 20 mm slit in the soil and places seed and fertilizer in the prepared slits in the stubble fields of soybean, maize and paddy. It reduced the loss moisture and draft force as compared to strip and roto till drill. Cost reduction by time and energy saving and optimization of environmental health by reducing soil compaction were less as compared to strip till drill machines.
Strip-tillage: A narrow strip of land along with the row is tilled and areas between the rows are left undisturbed. In this system planting is performed with a single tiller and planter in a single operation for highly mechanized tillage system. It combines the soil drying and warming benefits of conventional tillage with the soil-protecting advantages of no-till by disturbing only the portion of the soil that is to contain the seed row. This type of tillage is performed with special equipment and can require the farmer to make on the strip-till implement used, and field conditions.
Resource Conservation Technologies
RCT plays an important breakthrough for sustaining productivity, natural resource conservation with economic growth of the farmers. Rice-wheat system of this region where in conventional method of land preparation/sowing, not only disturbs the soil environment but also leads to atmospheric pollution. RCT has been proved to be the important step in the CA and economic growth. Which has substantial potential for minimizing the cost of production, soil health hazards and the negative impacts on the succeeding crops? The major components of CA includes minimal soil disturbance, maintaining soil cover and crop diversification. The evaluation of various “CA” technologies for their farm level impact in the country as detailed below has shown potential for resource conservation and sustainable farming.
1. Incidence of Weeds : Most studies tend to indicate reduced incidence of Phalaris minor, a major weed in wheat, when zero-tillage is adopted resulting in reduced use of weedicides.
2. Water and nutrients : Limited experimental results and farmers experience indicate that considerable saving in water (20-30%) and nutrients are achieved with zero-till planting and particularly in laser leveled and bed planted crop.
3. Increased yields: In properly managed zero-till planted wheat yields were invariably higher by 4 to 6 percent compared to traditionally prepared fields for comparable planting date.
4. Cost of production: This is a key factor contributing to rapid adoption of zero- ill technology. The cost of wheat production to reduces average 2000 rupees per hectare. Cost reduction is attributed to savings on account of diesel, labour and input costs, particularly weedicides.
5. Environmental benefits : CA involving zero-till and surface managed crop residue systems is an excellent opportunity to eliminate burning of crop residues which contribute to large amount of green house gases like CO2, CO, NO2, SO2 and large amount of particulate matter. Burning of crop residues, also contributes to considerable loss of plant nutrients, which could be recycled when properly managed. Large scale burning of crop residues is also a serious health hazard.
6. Crop diversification opportunities : Adopting CA system offers opportunities for crop diversification. Cropping sequences/rotations and agro forestry systems when adopted in appropriate spatial and temporal patterns can further enhance natural ecological processes, which contribute to system resilience and reduced vulnerability to yield reducing disease/pest problems.
7. Resource improvement: No tillage when combined with surface managed crop residues sets in the processes whereby slow decomposition of residues results in soil structural improvement and increased recycling and availability of plant nutrients. Surface residues acting as mulch, moderate soil temperatures, reduce evaporation, improve biological activity and provide more favorable environment for root growth, the benefits which are traditionally sought from tillage operations.
Mechanization strategy for CA
Agricultural machinery or tools, which support CA generally, refer to the cultivation with minimum or zero tillage and management of crop residues. Minimum tillage is aimed at reducing tillage to the minimum necessary that would facilitate favorable seedbed condition for satisfactory establishment of crop. Zero tillage is however an extreme form of minimum tillage. With the development of direct drilling machines almost all research work was attempted to define the responses of direct-drilled seeds in relation to soil micro environments. Different designs of direct drilling machines zero till drill, no till plant drill, strip till drill, roto till drill and rotary slit no till drill have been developed with controlled traffic measures for energy efficient and cost-effective seeding of crops without tillage. Laser guided land leveler helped to retain in soil moisture longer thereby reducing the irrigation demand. Agricultural machinery concentrated both on biological and mechanical parameters. Selection of most appropriate developed equipment for specific situation is essential in respect of field requirements, soil working condition. The tractor operated/ self propelled machinery/ technologies used for CA have the potential to meet the contemporary challenges and to increase productivity in a sustainable way.
Environmental protection for CA
CA can also help to mitigate climate change by reducing the emissions of green house gases into the atmosphere. The reduce emissions of fossil fuels compared to conventional agriculture. The use of fertilizer and agrochemicals can be reduced in the long term. Even the heavy machinery such as tractors can be reduced. Reduce the emissions resulting from the production of these inputs. However, the largest contribution to mitigate climate change with CA can be obtained from carbon sequestration and the storage of atmospheric carbon in the soil. Effects can be achieved for nitrous oxides as a result of changes in the nitrogen fertilizer and the soil water management. Suitable selection of fertilizers and placement in the soil can reduce the emissions also under conditions of minimum/zero tillage. These operations are important steps of residue management and should involve least input and maximum sustainable residue utilization. Improved soil structures achieved through the application of the techniques of CA can also reduce run off thus reducing pollution from recently applied pesticides. Improved water retention allows natural processes to occur and soil to break down pesticides, reducing the pollution caused by leaching. It will improve carbon sequestration Non-inversion of the soil avoids the release of carbon to the atmosphere.
Soil erosion, organic matter decline, compaction and salinization that frequently degrade good agricultural land; applying the principles of CA can have a positive impact on the first three and possibly the fourth soil erosion rates are hugely increased by agricultural activities which compromise soil structures. Soil structures are especially compromised by cultivation, in particular by mould board ploughing, which rips apart the soil and also reduces earthworm populations and thus the network of earthworm tunnels, which encourage better drainage and conversely improve water retention. Direct drilling has been found to be advantageous in terms of increase traffic ability, decrease soil compaction in long run, reduced soil erosion due to wind and water, decreased water evaporation and increased availability of water in the soil, decrease lodge condition of the crop, reduced investment in machinery due to reduced energy requirement and improved timely planting and harvesting. Crop residues may be effective to some extent in suppressing weed growth thus reducing use of herbicides. In depth long term studies on no tillage are conducted to see the effect on soil compaction, carbon sequestration, soil erosion, temperature of soil due to soil mulch cover, water infiltration etc and their effect on reduction in global warming.
1. FAO. (2002): Training modules on conservation agriculture. Land and Water Digital Media Series 22. Food and Agriculture Organization
2. Jones, C.A., Basch, G., Bayliss, A.D., Bazzoni, D., Biggs, J., Bradbury, R.B. (2006). Conservation Agriculture in Europe: An approach to sustainable crop production by protecting soil and water? Jeallott's Hill, Bracknell, UK.
3. Rautray, S.K. 2003. Mechanization of Rice-Wheat Cropping System for Increasing the Productivity", Paper presented during the National Technical Coordination Committee Meeting of Rice-Wheat Cropping System held at NBPGR, New Delhi, 28 July 2003.
4. Sidhu, H. S. 2001. Laser land leveling- A boon for sustaining Punjab Agriculture. Dept. of FPM, Punjab Agri. Univ., Ludhiana. Farm Machinery Bulletin-2007/01:13.
5. Shukla, L.N., Tandon, S.K. and S.R. Verma. 1984. "Development and Field Valuation of a Coulter Attachment for Direct Drilling". AMA, Japan, Vol.XV No.3.
6. Vijay Laxmi, Olaf Erenstein and R. K. Gupta. 2007. Impact of zero tillage in India's rice wheat systems. CIMMYT, New Delhi:15-17.
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