Does adoption of Conservation agriculture (CA) lead to increased compaction of agricultural soils and nutrient supplies coming from under CA cropping systems?
Conservation agriculture, on the other hand, increases soil organic matter (SOM) content and decreases surface runoff and compaction by maintaining year-round vegetative cover and reducing the number of passes made over fields. Along with reducing erosion, conservation tillage systems improve infiltration. Compaction reduces infiltration and, inevitably, restricts water flow to the root zone. The compaction caused by rainfall can be minimized by plant residue on the soil surface. Wet soils are particularly susceptible to compaction. Heavy equipment and tillage implements amplify damage to the soil's structure, decreasing pore space and limiting soil and water volume even further. Improving soil structure is the best defense against soil compaction. One important distinction between CA and other agricultural systems is that crop residues are left on the soil surface and are not incorporated into the soil. Chemical and organic fertilizers, however, should be banded into the soil with minimal soil disturbance using the appropriate planting equipment. The result of improved biological activity in CA soils means more nutrients recycling and a better nutrient supplying capacity of the soil. However, for high yield, some additional external nutrients may need to be applied.
A traditional element of crop rotation is the replenishment of nitrogen through the use of green manure in sequence with cereals and other crops.Conservation agriculture is based on the interrelated principles of minimal mechanical soil disturbance, permanent soil cover with living or dead plant material, and crop diversification through rotation or intercropping. Fertilizers and manures contain plant nutrients such as nitrogen, phosphorous and potassium, etc. So, when fertilizers and manures are added to the soil in the fields, then the soil gets enriched with nutrients like nitrogen, phosphorous and potassium, etc. Conservation of natural resources is very important because these resources are being depleted very rapidly. Depletion of natural resources has ill effects on the environment which in turn harms human life. CA reduces soil erosion, soil compaction and crusting, and optimizes the soil tem- peratures for successful crop production. This article reviews the role of conservation agriculture in improving soil physical health and its associated processes. Conservation tillage technology can reduce the soil bulk density and promote the redistribution of soil pore space in different soil layers, forming a better soil structure, thereby improving soil physical properties and soil aeration, improving rainfall infiltration and soil water storage capacity. CA is a farming system that promotes minimum soil disturbance maintenance of a permanent soil cover, and diversification of plant species. Soil compaction increases soil density. Roots are less able to penetrate the soil and are generally shallow and malformed. Because their growth is restricted, they're less able to exploit the soil for nutrients and moisture.
Biophysical constraints predominantly included uncertain monsoon and lack of availability of labour. Technological constraints such as non-availability of desired CA technologies and machineries and policy constraints lack of priority, promotion and incentives for adoption were also considered as major constraints. Conservation agriculture enhances SOC, nutrient availability and enzyme activity. Infiltration improved under conservation agriculture practices. Soil pH, SOC stock, available zinc and iron were the key soil quality indicators. Higher soil quality index in CA based treatments over conventional one. Conservation Agriculture is 20 to 50% less labour intensive and thus contributes to reducing greenhouse gas emissions through lower energy inputs and improved nutrient use efficiency. At the same time, it stabilizes and protects soil from breaking down and releasing carbon to the atmosphere. Crop rotation, cover crops, conservation tillage, and installed windbreaks are methods for better soil conservation that have an impact on both erosions as well as fertility. Plants that die decompose and mix with the soil. For thousands of years, farmers have conserved their soil. No-till farming assists in soil conservation as well since it implies no or minimum disturbance and planting seeds into the crop residue. The basic idea is not to leave soil bare, as bare areas are highly prone to erosion, and plants keep it in place with their root systems. Soil is a very important natural resource of India because agricultural production is basically dependent on the fertility of Soil. Food products like cereals, pulses, fruits and vegetables are obtained indirectly from the Soil. It is the natural process of wearing away topsoil, but human activities have accelerated the process. It is usually caused due to the removal of vegetation, or any activity that renders the ground dry. Farming, grazing, mining, construction and recreational activities are some of the causes of soil erosion.