Though agrochemicals have ushered in a Green Revolution, their overuse remains a threat. Let’s introspect on World Soil Day
This year has been an eventful one, for who would have thought that our protective guards, the Amazon rainforest, would be ravaged with fire. This is, however, not an isolated incident as burning forests to create land for agriculture is an age-old practice. Slash and burn agriculture is a widely-used method in which wild or forested land is cleared by cutting trees and any remaining vegetation is burnt. The resulting ash is said to provide the newly-cleared land with a nutrient-rich layer that acts as a fertiliser for the crops. Every year, people in north and west India battle smog and poor air quality only because farmers in the region opt for burning the stubble instead of using more scientific methods to dispose the biomass. They do this as they find burning crop residue to be more cost-effective. But such unscientific methods do more harm to the soil quality and to agricultural yields in the long run than the farmers can imagine.
The right crop for the soil type: India has various types of soil, ranging from the fertile alluvial of the Indo-Gangetic plains to the black and red soil of the Deccan Plateau. For instance, in the State of Tamil Nadu, soil in the fields in Salem and Periyar districts is red while that in the fields of Coimbatore and Ramanathapuram is black. Different kinds of soil are suited to growing different types of crops through their unique physical, chemical and biological properties. Alluvial soil is a fertile soil, rich in potassium and is suitable for agriculture, especially for crops such as paddy, sugarcane and plantain. Red soil has high iron content and is fit for crops like red gram, Bengal gram, green gram, groundnut and castor seed. Black soil is rich in calcium, potassium and magnesium but has poor nitrogen content. Crops like cotton, tobacco, chilli, oil seeds, jowar, ragi and maize grow well in it. Sandy soil is low in nutrient content but is useful for growing trees such as coconut, cashew and casuarinas in areas with high rainfall. However, with better irrigation and treated seeds, factors like these have seemingly become irrelevant to the farmers. To force a land fit for jowar and ragi to produce paddy by using fertilisers indiscriminately is not only a waste of resources, it adversely impacts the soil health and may affect the future growth of crops too.
Repeating single crop cultivation over the years: Traditionally, farmers chose to cultivate a number of crops on a piece of land and even left it uncultivated so as to allow it to regain fertility. This rotational farming helped the soil regain the nutrition that it had lost in the previous crop cycle. Both land-use change and intensification of agricultural production on existing croplands can have significant adverse impacts on soil but these impacts depend critically on farming techniques.
Inappropriate cultivation practices can reduce organic matter and increase erosion by removing permanent soil cover. The removal of plant residues can reduce nutrient contents and increase greenhouse gas emissions through loss of soil carbon. However, fallow land is more of a compulsion today than a choice — keeping land uncultivated means financial loss, something farmers can ill-afford at a juncture when they are battling poor prices. Though the Government has been working in this direction but the response to the same has been lukewarm.
Lack of knowledge: The variety of crops cultivated earlier is gone as, in pursuit of more income, farmers cultivate only those crops that tends to fetch good prices. As a result, a piece of land is used for cultivating the same crop cycle over and over for years together. Farmers also choose specific crops, also known as cash crops, over food crops in order to get a better price for their produce. However, their sustained cultivation harms the soil health as it naturally drains it of its fertility. To cope with it, farmers have to use large amounts of fertilisers. This jeopardises soil health all the more. To counter this, farmers must be made aware of the right kind of agrochemicals needed for their crops and how they must be used judiciously.
The fact remains that agrochemicals have ushered in the Green Revolution in India and turned the country from a food-deficient nation to a food grain-surplus country. According to the Ministry of Agriculture, use of technical grade pesticide in India has gone up from 47,000 tonnes in 2001 to 53,000 tonnes in 2017. Schemes like soil health card and various irrigation projects have only added to India’s capacity to remain self-sufficient in terms of its food requirement. Yet, the dangers of overuse of these chemicals and fertilisers remain a real threat to India’s future food security, the environment and soil health. These issues need to be countered through awareness, education and long-term policy decisions and not knee-jerk reactions.
(Writer: RAJESH AGGARWAL; Courtesy: The Pioneer)