Soil Health Management issues in India

Soil and nutrient loss are among the major impediments to a stable and sustained agricultural development. Admittedly modern agricultural practices with excessive thrust on use of chemical fertilizers helped in increasing agricultural production manifold in the country. However, indiscriminate and irrational use of chemical fertilizers such as nitrogen, phosphorus and potassium (NPK) has caused excessive damage to the soil, soil erosion, soil salinisation, depletion of groundwater and loss of balance of natural habitat. Some of these agricultural practices have resulted in causing irreversible damage to the soil health. There is an urgent need to make people aware about taking good care of the soil. Maintaining healthy soil implies managing the land sustainably. The International Union of Soil Sciences (ISUS) in 2002, had adopted a resolution proposing the 5^th of December as World Soil Day to celebrate the importance of soil as a critical component of natural system and a vital contributor to human wellbeing. Accordingly, Food and Agricultural Organisation of the United Nations (FAO), has declared December 5 as World Soil Day. This year’s theme of World Soil Day  is “Be the solution to soil pollution”.         

Functions of Soil

Soil performs five essential functions:

1.     It regulates water flow. It helps in controlling flow of rain and irrigation water. Water and dissolved solutes flow over the land or into and through the soil.

2.   It is vital for sustaining animal and plant life. It is estimated that 95 percent of food is produced on soils.

3.    It helps in filtering and buffering potential pollutants. Apart from filtering and buffering the minerals and microbes present in the soil are responsible for immobilizing and detoxifying organic and inorganic materials.

4.      Various nutrients are stored, transformed and recycled in the soil,

5.   It provides physical stability and support to plant roots, man-made structures such as buildings, roads, bridges, dams etc.     

Soil Health

Soil health is also referred to as the quality of the soil. It is defined as the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals and human beings. Therefore, management of soil is of paramount importance so that it is kept productive for the future generations as well.  Thus, the need for keeping it healthy assumes importance. However, there is no one way to measure the health of a soil. A number of indictors have been identified relating to the physical, chemical and biological properties in soil which provide an idea about the health of soils. Physical indicators like good aggregate stability, available water capacity, bulk density and good infiltration focus primarily on how water moves through soil, which can be felt by observing. Chemical indicators focus on the availability of nutrients for crops in the soil. Macronutrients like nitrogen, phosphorus and potassium, micronutrients like calcium, magnesium, sulfur, zinc, iron etc. electric conductivity, pH, of the soil, which form chemical indicators, are all measurable and the result gives an idea of soil’s health. Biological indicators which include organic matter, soil enzymes, soil respiration, earthworms, can be measured. However, biological indicators are by far the least understood.

Most of the nutrients in the soil are not directly available to the plants. To be used by plants, nutrients in organic matter must be converted into inorganic forms through decomposition and mineralization through soil organisms. It is estimated that one teaspoon of soil contains 10 crore to 100 crore individual bacteria consisting of thousands of species of microbes. Microbes, specifically the fungi, can increase soil aggregation and water holding capacity of the soil. It is important for farmers to enhance microbes in their soils. This is possible by adopting better soil management practices such as reducing soil disturbances, adding biological diversity, keeping as much living roots as possible in soil and keeping the soils covered to the greatest possible extent. Physical soil disturbance by way of tillage can be disruptive to microbes. Different plants must be grown to achieve high level of plant diversity. Since living roots provide the easiest source of food for soil microbes, growing a long season crop or a cover crop after a short duration crop really helps in enhancing microbes. Further, keeping the soil covered helps in conserving moisture, reducing temperature, intercepting raindrops, suppressing weed growth. All these soil management practices help in building a congenial environment for the growth of microbes in the soil and there is an urgent need to popularize these soil management practices.    

Of course, there are other direct ways to manipulate the soil by adding microbes through use of products known as bio-pesticides and bio-stimulants. While bio-pesticides are used to get rid of microbes that are not desired in the soil, bio-stimulants aim to enhance plant growth by adding some microbes into the soil that affect plant nutrient acquisition. Of late these microbial products have become big business. Farmers, in their anxiety to get better plant growth and yield, are tempted to make indiscriminate and irrational use of these products. However, these products may not be highly effective all the time. Therefore, before resorting to the use of a microbial product, a farmer has to get answers to these queries: (1) Whether the crop needs the microbial product?, (2) Whether the organism intended to be introduced through the microbial, is already present in the soil?, (3) Whether any organism present in the soil is already doing the same job?, (4) Whether the organism present in the microbial product can survive in the soil?, (5) Whether it can compete with the microbes already present in the soil? Since there is no technology available commercially as yet, it is difficult for the farmers to get answers to the above queries. Hence, farmers have to be very selective in the use of these microbial products. Before using bio-stimulants over a large tract, it is advisable that the farmers should test the product on a smaller patch and monitor the disease, yield and plant health.  

Soil Health Card

Soil Health Card (SHC) Scheme was launched by the Government of India in 2015, with an objective of providing every farmer a soil nutrient status of his land and advising him on the dosage of fertilizers and essential soil amendments for ensuring good soil health. It is basically a printed report given to a farmer for all his land holdings indicating the nutrient status of macro nutrients like Nitrogen, Phosphorus and Potassium (NPK), secondary nutrient like Sulfur, micronutrients like Zinc, Iron, Copper, Manganese and pH, EC, OC. Based on all this SHC recommends fertilizer application and the soil changes required for the land.

Farmers can derive a number of benefits from Soil Health Cards:

1.      Farmers can decide as to which types of crops to be cultivated for getting more income.

2.   Appointed authorities will monitor the soil at a regular interval of 3 years and the farmer will be provided with a report.

3.   Farmers will get the support of professionals engaged by the government for adopting remedial measures.

4.      Farmers can plan for their land and also make future crop planning.

5.    Soil Health Card gives clear idea about specific nutrient deficiency of the soil. Accordingly, the farmer can be advised on the right crop to grow.    

FAO on Soil Pollution

FAO is very much concerned about the issues pertaining to soil pollution and has been playing a proactive role in building awareness and taking measures to reduce pollution in soils. As per FAO, soil pollution causes serious threats to global food safety and food security. It is not that farmer alone is responsible for the pollution of the soil. Hundreds of chemicals which are commercially produced, plastic and electronic waste, non-treated waste water find their way into soil to pollute the soil and the pollutants present therein enter the food chain resulting in serious consequences for the health and well being of people. Human activities are the main source of soil pollution. According to Maria Helena Semedo, Deputy Director-General, FAO, “About 33 percent of all soils are degraded and soils continue to deteriorate at an alarming rate. Soils act as a filter for contaminants. But when its buffering capacity is exceeded, contaminants can enter the environment and the food chain. This undermines food security by making crops risky and unsafe for consumption.” Therefore, urgent action is required to address the issue of soil pollution and here comes the necessity for sustainable soil management practices. Of course this requires greater political support and investment as well. In order to reduce soil contamination at the state, industrial and consumer level and make soils pollution free, FAO has come out with a number of recommendations.     

1.  Growing cities are producing mounds of garbage which are used as landfill. Pollutants from the garbage enter into soil and contaminate it. Efforts may be made to recycle the garbage since around 80 percent of the garbage could be easily recycled.

2.   Electronic waste is a new emerging threat to soil. Electronic waste is considered to be the fastest growing pollution problem affecting soils since about fifty million tons of electronic waste are generated every year. FAO encourages people to donate or recycle old devices rather than throwing them away.

3.   Indiscriminate use of agrochemicals is a major reason for soil pollution and degraded agro-ecosystems. It is observed that top agro soils in huge tract of land contain residues of pesticides. There is an urgent need to regulate the use of agrochemicals. FAO has urged upon the governments to promote responsible and sustainable management of agrochemicals.

4.     One third of the plastic produced globally find their way into soils, with plastic particles  entering into food chain and environment. FAO has urged upon the governments to introduce stronger environment policies and regulations to prevent the use of excessive  packaging and chemicals by industry. Every person can also contribute to solving the problem by carrying a reusable bottle, grocery bag and buying products with reduced or recycled packaging. It may be pertinent to mention here that Indian cities produce 15000 tonnes of plastic every day, 6000 tonnes of which are dumped in landfills polluting soils. Twentyfive of the Indian States and Union Territories have some form of ban on polythene carry bags, but there is hardly any visible impact of the laws at the ground level due to poor implementation.

Soil Loss and its Economic Impact

There can be serious economic impact of soil erosion and soil nutrition loss. In order to have a better understanding of the economic damages incurred by soil loss UNDP-UNEP Poverty-Environment initiative conducted a Pilot study in Malawi. Meanwhile, the report of the study has been published and its findings are quite alarming. According to the report a 10 percent increase in soil loss would produce monetary losses of about 0.26 percent of the GDP of Malawi and 0.42 percent of the total agricultural production value. Similarly a 25 percent increase in soil loss would result in a reduction in GDP by 0.64 percent and total agricultural production value by 1 percent, which means higher the soil loss, larger is the adverse economic impact. Since soil loss has a high economic cost by way of reduced crop yield, nations must put top priority on preventing soil pollution so that the soils remain healthy. There is an urgent need to conduct similar studies in various states of India as well. In order to assess the economic impact of soil loss in India, central government may initiate steps to institute such studies immediately.

There is hardly any discussion or debate on issues related to soil pollution in India. Hence, there is a need to educate people on soil pollution and its ill effects. Of course, the farmers need to maintain the health of soils by desisting from indiscriminate and irrational use of chemical fertilizers and pesticides so that soils remain productive. Simultaneously, the government, industries and people must take all effective measures to reduce soil pollution. Ultimately, maintenance of healthy soils helps in ensuring safe and nutritious foods which in turn paves the way for achieving the ‘Sustainable Development Goals’ and ‘Zero Hunger’. 

Published in December 2018 issue of SmartAgripost as its cover story.