ET: India’s Soil Crisis: July 12, 2011

NUTRITIONAL CRISIS
In June, IISS uploaded maps of 18 states that show nutrient deficiency district by district. The maps paint a scary picture. Large parts of India are deficient in two or more critical nutrients. Areas like the Indo-Gangetic plains – Punjab, Haryana, Uttar Pradesh and Bihar  — which produce nearly 50% of our grains  and feed about 40%  of our population — are seeing multiple deficiencies.

 Why is this happening? In the past, farmers used to plough the stalks left standing on the field after the harvest, cowdung, etc, back into the soil. This ensured that nutrients taken out of the soil were replenished. The green revolution, which started in the sixties, changed all that. Highyielding crop varieties need more water and nutrients – which span from macronutrients like Nitrogen and Phosphorus to micro-nutrients like Copper and Boron.

 

However, due to imbalanced fertiliser use, hardly any of these nutrient cycles are being completed. Farmers today use a lot of Urea (Nitrogen), some Potassium and Phosphorus, but not much else. Further, they choose fertilizers more by affordability and availability than what the soils need.

 

Apart from retarding growth in yields, this unbalanced use has also damaged soils. Too much urea, for instance, turns soils acidic. The ICAR report estimates that 6.98 million hectares, or 2% of India’s total geographical area, have acidic soils. These are mostly in North East India, south Chhattisgarh and Kerala. Another 6.7 million hectares are salt-affected.

 

In the absence of historical data on nutrients, the degree of decline cannot be ascertained. The irrefutable point is that these soils are increasingly incapable of supporting agriculture.

CARBON DEBIT
In Bagli, Kishore Lal Singh says the soil in his fields is changing from “bareek” (fine) to “kadak” (hard). In healthy soils, crop residues transformed by earthworms and other soil fauna into soft and spongy organic matter called humus (or organic carbon). This soaks up water, creates an environment where soil fauna like earthworms thrive, and binds the soil’s three constituents: sand, silt and clay. Without humus, the soils compress and harden.

 

It also contains organic carbon, the other nutrient cycle not being completed today. Farmers, in a hurry to plant the next crop, burn their fields to clear stalks left standing after the harvest. Cow dung is scarcer. That’s partly because, with mechanisation, fewer households now need bullocks. The decline of grazing grounds has meant only households large enough to afford fodder can keep milch animals. “The recommended amount of farmyard manure is 5-10 tonnes per hectare,” says Y Muralidharudu, the project coordinator for the soil testing programme at IISS. But, in India, farmers add anywhere between zero to five tons.

 

Poorer farmers, says PS Vijay Shankar, an activist with Samaj Pragati Sahyog, a NGO working with dryland farmers near Indore, sell manure instead of ploughing it into their fields. Or, they use dried dung as fuel.

 

The outcomes are predictable. DLN Rao, project coordinator for the All India Network Project on Soil Biodiversity-Biofertilizers at Bhopal’s IISS, estimates that humus depletion in the top 0-15 cms is nearly 50%, although it can be occassionally as high as 60-70% in some soil types. There is, he adds, 10-20% loss in the 15-100 cms below that top layer.

 

As humus falls, properties of the soil change. For example, its ability to absorb water reduces, resulting in erosion. The ICAR report estimates that a total of 126 M ha is suffering from various degrees of water erosion. Of this, 0.68 million hectares are seeing ”severe”, “very severe” and “extremely severe” erosion. Another 0.2 million hectares is seeing “moderately severe” erosion. Wind erosion is more. The report estimates that “very severe and severe wind erosion occur in 16% of India’s total geographical area.”

 

Both these processes contribute to desertification — soil turning into a desert. About 81 million hectares of India, or 25% of it, is seeing desertification, says a 2009 Isro paper titled ‘Desertification/land degradation status mapping of India’. Between unbalanced fertilisation and the drop in humus, anecdotal information suggests that the number of earthworms and other soil insects is falling.

FIXING INDIA’S SOILS
Both the 10th and 11th Plan documents allude to our weakening soils. However, it is a crisis that we are just starting to deal with. One of the few exceptions is the government’s switch to Nutrient-based Subsidy. As a response to growing micro-nutrient shortages, it falls short. Partly because the price signals it sends out about the nutrients to use are national while the shortages are local. Partly because the government has decontrolled prices of P and K while holding on to prices of N. As a result, every time P and K prices soar, farmers dump more urea than other fertilisers. And partly because it doesn’t extend the subsidy to organic manure or to all 20 micronutrients – it only covers Boron and Zinc.

 

Research itself is lacking. The research fraternity has focused on increasing yields. In the process, other aspects of agriculture have been ignored. We do not have baseline data about nutrient concentrations — The quantum of deficiency in these maps has been calculated by gauging the minimum concentration of a nutrient required (for that soil type) for above normal yields.

 

The IISS data, as shown in the maps, was derived from samples collected by soil-testing labs. But macronutrient deficiency has been mapped for only 18-odd states. In the case of micronutrients, we know their concentration in even fewer states. Then, some of this data is very old.

 

Only now, with the help of a Rs 10 crore project from the Agriculture Ministry, is IISS methodically surveying nutrient deficiency across India. “The idea is to cover 10% of villages in every district, collecting samples from the fields of six farmers from each village, including small, medium and large ones,” says Muralidharudu. The government is also starting other studies. Like one, led by the National Centre for Organic Farming, Ghaziabad, to assess microbial population and activity in the soil.

 

Some of the states are doing interesting work, though. Gujarat and Tamil Nadu are setting up more soil testing labs. It is an example the rest of India needs to follow. “India has 115 million land holdings, but our labs cannot process more than 8 million soil samples in a year,” says Muralidharudu. “It will take us 15 years, at this rate, to tell every farmer what his soil needs.”

 

That said, it will take more than balanced fertilization to fix India’s soils. Says IP Abrol, the chairperson of the Working Group providing inputs to the 12th plan on natural resource management and rainfed farming, “The larger question is about the soils’ physical condition – can they support the hydrological cycle? And for that, you need humus and soil biota.”

 

Indeed. Field studies at IISS and elsewhere suggest earthworm populations, organic carbon levels and yields are the highest when a combination of balanced fertilization and farmyard manure is used. But India doesn’t have enough cow dung. Organic waste can be used instead of cow dung, but we need to figure out better ways to segregate organic and inorganic waste, and to get it across to fields.

 

Here, Andhra might have an answer. As a part of its organic farming drive, the state is helping farmers set up composting pits where agricultural and household wastes can decompose into manure that is then ploughed back into the soil. Apart from that, it is handing out soil health cards to its farmers.

 

Such solutions need to be encouraged. Or the country will find itself contemplating Malthus.