Conservation AgricultureOpportunities for intensified farming and environmental conservation
Dinesh Sah, P Debnath, SK Pattanaaik and D Sen
Conservation Agriculture (CA) is an approach in managing agro-ecosystems for improved and sustained productivity, increased profits and food security while persevering and enhancing the resource base and environment. Conservation Agriculture methods enhance natural biological process above and below the ground by reducing interventions such as mechanical soil tillage to an absolute minimum. They also ensure that application of external inputs, such agrochemicals and minerals or organic nutrients, do not interfere with, or disrupt, biological processes. Conservation agriculture is a proven approach to food production that is now widespread in several of the world’s high-income countries and makes possible benefits to smallholder farmers, consumers and rural and National economies in Asia and Africa.
PRINCIPLES OF CONSERVATION AGRICULTURE:
Conservation Agriculture offers farmers a variety of assortment of practices, but its core has three principles which are linked to each other, namely:
Minimal soil disturbance : Minimum soil disturbance refers to low disturbance, no tillage and direct seeding. The disturbed area must be less than 15 cm wide. There should be no periodic tillage that disturbs a greater area than the aforementioned limits.
Permanent organic soil cover : In an undisturbed soil, the crop residues remain on the soil surface and produce a layer of mulch. This layer protects the soil, stabilizes the soil moisture and temperature in the surface layers. Thus this zone becomes a habitat for a number of organisms, these organisms macerate the mulch, incorporate and mix with the soil and decompose it so that it becomes humus and contributes to the physical stabilization of the soil structure. Three categories of organic soil cover are well-known : 30-60%, > 60-90% and > 90% ground cover, measured just after the direct seeding operation. Area with less than 30% cover is not considered as Conservation Agriculture.
Diversified crop rotations of annual crops and plant associations of perennial crops: Diversified crop rotations should involve at least three different crops. However, repetitive wheat or maize cropping is not an exclusion factor for the purpose.
Guiding principles for productive and sustainable cropping with CA
Do not cultivate fields, as ploughing is unnecessary, takes time and money, and robs soil moisture and structure.
Do not burn stubble from previous crop, but retain as mulch of it and other residue as possible on surface of the soil.
Allow livestock to graze on stubble. This does not work against the many benefits of CA. Many countries have successfully integrated livestock into the system.
Sow seed and fertilizer using a conservation agriculture seeder that allows planting through surface residue into narrow openings in the soil.
Farmers can sow early as no ploughing is needed. Planting can start as soon as soil conditions are favorable and rains have resumed.
When the rains are late, consider early dry sowing, which is successful in many countries.
Control weeds before sowing with a non-selective, non-residual herbicide.
New approaches may be needed to manage soil fertility and control pest and disease, these are different ways in conventional system.
Manage major soil problems according to best practice to optimize yields, for problems such as hard pan, acidity and salinity.
Use diverse crop rotations to break the cycle of pest and diseases. Effective rotations of cereals with legumes, brassicas, other crops and forages help in minimizing the problems.
Conservation Agriculture Addresses Development Like
Agricultural production-CA has tremendous potential for achieving sustainable yield increases by improving the growth conditions for crops and the efficiency of input.
Natural resource base-CA reverses the soil degradation processes and builds up soil fertility by facilitating better infiltration of rain water and enabling the recharge of groundwater which reduces erosion and leaching and, in turn, water pollution.
Biodiversity-CA conserves and enhances biodiversity in the field.
Labour shortage-Ca eliminates power intensive soil tillage, thus reducing the drudgery and labour required for crop production by more than 50% for smallholder farmers. For mechanized farms it reduces fuel requirements by &0% and the need for machinery by 50 per cent.
Climate change-CA reduces crop vulnerability to extreme climate events. In drought conditions, it reduces crop water require- ments by 30 per cent, makes better use of soil water and facilitates deeper rooting of crops. In extremely wet conditions, CA facilitates rain water infiltration, reducing the danger of soil erosion and downstream flooding.
Livelihoods-CA gives farm families opportunities to improve their livelihoods. Farmers who adopt CA no longer need to spend time tilling and can use that time in other ways, such as on farm processing, which adds value to their production.
Benefits of Consecration Agriculture : Benefits of Conservation Agriculture can be grouped as : (a) Economic Benefits (b) Agronomic Benefits (c) Environmental Benefits.
Economic Benefits : Economic benefits results from adoption of CA are (i) Energy and labour savings (ii) Time savings, and (iii) optimal seeding rate.
Agronomic Benefits: Adopting conservation agriculture leads to improvement of soil productivity due to (i) Organic matter increase (ii) water conservation, and (iii) Improvement of soil structure.
Environmental Benefits: Environmental advan- tage includes (i) Improvement of water quality (ii) Improvement of air quality (iii) Reduced GHG emissions and water use, and (iv) Biodiversity increase. Constraints to adoption of conservation agriculture The limited availability of affordable and appropriate seeding machinery that is locally produced and maintained.
The mistaken perception that soil cultivation is essential for high crop production.
Limited knowledge and experience of how to adopt CA practices.
Perception of worsening of weed, pest and disease infestation.
Unwelcoming policy and extension environments.
Steps to encourage farmers to adopt conservation agriculture.
The following points can lead to the widespread adoption of conservation agriculture:
Raise awareness: Education is the first need toward achieving understanding and acceptance of conservation agriculture in principle from farmers and the National agricultural research and extension systems upon which they depend.
Local verification and modification of technology: Locally suitable and proven technology need to be accepted for management of stubbles and other residues in the field, the time of sowing, soil fertility management, weed management, and IPM.
Provide appropriate and affordable seeders: As a practical matter, participating farmers must have access to appropriate seeders beginning with participatory research and demonstration. The writers are from College of Horticulture and Forestry, CAU, Pasighat For further details contact:-Public Relation & Media Management Cell,