4-Climate Resilient and Environmental Benefits

Transcript

Hello friends. We know that agriculture provides us with our basic needs like food, fuel and fodder but it also contributes to the emission of greenhouse gases. These gases are released through soil organic matter decomposition or the use of fossil fuel or through residue burning.

In the last 30 – 40 years, we extensively practiced tilling soil and this released 30 to 50 % carbon from our soil into the environment resulting in the deterioration of our air quality.

Now, conservation agriculture is being looked at as a potential solution. We had looked at the three main principles of conservation agriculture: minimum tillage, soil cover and crop rotation. If we do minimum tillage and permanently or semi cover the soil, then there will be reduced emission of carbon in the environment and our soil will be healthy. We can understand it better by looking at the Reicosky, 2003 ‘C wheel’.

We can understand carbon in two parts. First, if our soil is fertile then there would be more organic matter in the soil and we would get good production and this will improve our economic condition. Second, if we stop carbon emissions then CO2 sequestration will stop and our air quality will improve. If we have more organic matter in the soil, then the water holding capacity and the use efficiency will increase. According to a study by Hudson, if we increase the organic matter by 1% then the water holding capacity of soil increases by 3.7 %. Also more organic matter in the soil means that water will seep into the soil slowly and reach the plant. The rain water will also infiltrate and go down.

The Cation exchange capacity(CEC) will increase and this will increase the availability of nutrients. One study has shown that if we increase the organic matter in the soil then it increases the CEC by 20% to 70% provided they are clay minerals or metal oxides.

Conservation agriculture also stops soil erosion by almost hundred percent as the crop residue decays slowly and a layer of organic matter develops. In fact, conservation agriculture had started as a response to the problem of soil erosion.

This also improves the water quality. When there is an increase in organic matter then there is also increase in biological, physical and chemical activities and this decreases soil compactness. This leads to an improvement of soil structure and tilth and there is aeration for the plant. All this slowly reduces the release of CO2 in the environment as the carbon is being trapped in the soil and less of it is released.

One benefit of this is that as there is more organic matter in the soil so we require less fertilizers. Also due to tilling, the availability of nitrogen increases in the short term due to mineralization but in the long run the availability of nitrogen decreases.

There is an increase in soil buffer capacity and in biological activities. As we are not disturbing the soil structure, there is an increase in the different types of biota in the soil. They get an ideal environment and their numbers and variation increases. Also there is no run off when we use pesticide or herbicide in our farm as there is a layer of organic matter that absorbs and increases the efficiency of pesticides.

So we can say that carbon is at the center and plays an important role. Conservation agriculture increases the availability of organic matter. In a research conducted for Eastern gangetic plains, it was found that if we do conservation agriculture then almost 10% CO2 equivalent emission decreases and this figure was between 10 to 20% in other studies.

Besides this, conservation agriculture mainly zero tillage and DSR, there is increased resilience against climatic shocks like floods and drought. I would like to share an example with you. We had organized a DSR demonstration in Kathaili village. Now there was an unexpected flood during the month of September in that village and we found that farmers who had done DSR in lowland, their crop was saved while the transplanted paddy crop of farmers next to the DSR plots did not survive the flooding.

Like I said earlier, with conservation agriculture, the water holding capacity increases as there is an increase in organic matter and water slowly is released for plants. So even in drought like situations, the plant gets water.

We had also looked earlier at how crop residue retention maintains the balance of temperature between 5 to 6 degree Celsius. So due to climate change, if there are any variations in temperature then our yield does not get affected by such things. Therefore, we can say that conservation agriculture is climate resilient and it has many benefits.

So friends today we looked at the various environment related benefits of conservation agriculture. Conservation agriculture increases our production and improves our economic condition.

Thank you.