Solving India’s soil infertility problem with precision technologies
Ill-informed farming practices and indiscriminate use of fertilizers and pesticides have all but depleted our soil of micro-nutrients and groundwater. Let’s look at ways to remedy the situation.Rajan Aiyer
Many of us would have noticed how the elders in the family often rue about fruits and vegetables not tasting as good as they used to. From mangoes and bananas to tomatoes, chillies, and other farm produce, the flavours and taste profiles have slowly changed over a couple of decades. The younger and the well-traveled ones among us can verify this by eating these fruits in other parts of the world.
This slow erosion of flavours in our farm produce can be singularly attributed to the degrading soil quality in most parts of India, in turn caused by excessive use of pesticides and fertilizers.
Ill-informed farming practices and indiscriminate use of fertilizers and pesticides have all but depleted our soil of micronutrients and groundwater, often creating a situation of soil infertility. We have not just over-cultivated our soil, but also excessively irrigated and polluted the land. As of today, the use of water for irrigation accounts for 80 percent of the total available groundwater.
In states like Punjab, farmers often grow cash crops like sugarcane in a complete disregard to the soil and climatic conditions. With generous government subsidies on electricity and other farm inputs, farmers often go overboard with pump irrigation, chemical fertilizers and shun the sustainable age-old organic soil revival practices and appropriate crop rotation. In addition to imprudent use of resources, Indian soil degrades faster due to oxidation of carbon content under high temperatures.
Where does the solution lie?
In order to avert yet another agrarian crisis because of permanent soil degradation, we urgently need to take a host of steps. First, we must reduce the indiscriminate use of fertilizers that is creating huge imbalances in the quantity of nutrients in our soil.
The NPK (Nitrogen Phosphate and Potash) ratio measures the quantity of these three vital nutrients in soil. While the ideal ratio stands at 4:2:1, in states like Haryana and Punjab, it was measured at 60.7:12.7:1, and 56.8:13.5:1, respectively in 2014. The worst offending state is Rajasthan with an NPK ratio of 180:55:1 as measured in 2014. These ratios indicate an extremely high quantity of nitrogen and phosphate in our soil, leading not just to poor tasting fruits and vegetables, but also poisoning of soil and water.
Use of modern technology can reduce or mitigate such indiscriminate use. Handheld devices with optical crop sensors can measure the health of plants and tell farmers if their crop has excess nitrogen, phosphate, or potash. Using the readings from such devices, farmers can spray just the optimum quantity of fertilizers to get the ideal NPK ratio.
Separately, precision agriculture tools such as the laser land leveller can reduce indiscriminate use of groundwater for irrigation by up to 30 percent in rice and wheat crops. These and other tools are widely available and farmers in many developed economies use them to optimise use of water, fertilizers and seeds. For example, GPS and optical sensors-based field mapping can allow farmers to understand their crops at a micro scale and with high precision, leading to conservation of resources and reduced negative impact on the soil.
In 2015, the Indian Council of Food and Agriculture (ICFA) launched the soil health card scheme. Under this scheme, ICFA samples soil from different farmlands every three years for a chemical analysis of nutrient component and deficiency. This is a commendable strategy and will enable policymakers, scientists, and other stakeholders to take corrective steps towards soil fortification. However, such schemes must be adopted at the state level to reform soil health. Farmers should also be trained on reading the analysis results so that they can change their practices based on the cards’ analysis and recommendations.
Another measure that can potentially increase soil health is promotion of organic farming practices. Organic farming reduces dependability on chemicals fertilizers, which is the key reason of soil degradation.
Lastly, the government should encourage crop rotation practices, especially in areas such as Punjab and Haryana. Continuous cultivation of water intensive crops like sugarcane and rice has resulted in their water tables running low at 149 percent. Alternating crops with millet, which consumes less water and has a high nutritional value, can increase the soil fertility and balance nutrients present in it.
Implementation of these initiatives or recommendations needs long-term commitment and support from State governments and their agricultural agencies. We must nudge our farmers towards a more sustainable way of agriculture, while encouraging judicious use of water and fertilizers that preserves our soil. At stake is not just the quality of fruits and vegetables, and other produce that we consume, but also farmers’ livelihood and our country’s food security.