The International Year of Soils was celebrated in 2015, the same year that India’s unique programme of Soil Health Card was launched on February 19 to assess the nutrient status of every farm-holding in the country — a staggering figure of 14 crore. Coincidentally the Sustainable Development Goals (SDGs) were also unveiled in 2015.

Agriculture, with soil and water at the heart of it, sustains life on Earth. It is estimated that the hunter-gatherer way of life evolved to farming about 12,000 years back, in the Fertile Crescent of the Middle East. DNA studies have shown that these pioneers moved eastwards, having striking resemblance to South Asians. Our ancestors practised natural farming in harmony with Nature. However, with the progress of science and the need for more food for the growing settled way of living, the move to chemical fertilisers and pesticides became inevitable. The first synthetic fertiliser was calcium nitrate manufactured in 1903, and thereafter there would be no looking back.

Global concern on the ill-effects of the continuously increasing use of chemicals to boost production and productivity is mounting and countries are collaborating for ways and means for reversing this trend to make way for sustainable use of natural resources in agriculture. Unbridled use of chemicals has led to disruption of soil microbial activity and organic carbon and also eutrophication of all types of water bodies.

Studies indicate that one-third of the world’s soils are degraded due to several reasons which include depletion of organic carbon and nutrient imbalance. Deterioration of soil nutrients also plays on the quality and safety of agri produce and thereby comes the role of soils in achieving SDG2 — zero hunger. Excessive use of chemicals also increases greenhouse gases. Hence the global discourse in multilateral fora is inevitably including soils too. The word ‘soil’ may not have been mentioned in any of the 17 SDGs, but being a part of ‘land’ it has ramifications on number of SDGs including poverty, zero hunger, clean water and sanitation, good health, climate change, and life on land.

Soil indicators

The Food and Agriculture Organisation (FAO) has framed number of soil indicators in the Global Land Degradation Information System (GLADIS) and the Status of the World’s Soil Resources Report (SWSR). These indicators, while rating soil health in absolute terms with reference to the physical properties, also speak about relative soil health vis-à-vis its actual use. Hence appropriate cropping is essential for improving soil health. Differentiation between problem soils and degraded soils is very evident, the former having characteristics which pose problems for optimum use and the latter in which unwise management interventions have created supplementary environmental and productive problems.

The Voluntary Guidelines for Sustainable Soil Management were adopted by FAO Council in 2016. The Global Soil Partnership was established in 2012 to develop a strong interactive partnership and enhanced collaboration between all stakeholders to improve the governance and promote sustainable management of soils. The implementation of the five pillars of action hinges on soil organic carbon, soil pollution, soil erosion and soil biodiversity.

The G20 Agriculture Ministers declaration in their meeting in 2018 in Buenos Aires, Argentina, specifically referred to ‘Healthy Soils to Support Role of Agriculture in Sustainable Human Development’, reiterating the commitment of the German Presidency of 2017. Concern was expressed on the role of soil and riverbanks degradation and loss of agricultural land play in increasing vulnerability of society, and that this was expected to increase. ‘The importance of development of bio-economy for effective implementation of production systems that ensure sustainable soil use was also underlined’. Similar concerns found place in the subsequent Presidency of Japan in 2019 and current one of Saudi Arabia.

Management of forests

The direct and indirect role that sustainable management of forests has on soil health is a dimension that cannot be ignored. Studies have shown that integrated watershed management impacted soil health in a positive manner, with significantly higher organic matter. The tag line of the International Year of Soils 2015 was “healthy soils for a healthy life”, also attributing forests and forest soils as an essential contributor to agriculture production and global food security. Sustainably managed forests are the major sinks of carbon, prevent soil erosion, and ensuring a balanced water cycle.

This is especially relevant in steep slopes with thin soils, which degrade very rapidly but would take many many years to repair, if at all. Hence the challenges that farmers in the hills face are many. Forests also play a role in preventing or reducing salinisation. Hence the important symbiotic relation between healthy forests, healthy soils and food security cannot be over emphasised.

Over 600 species have been reported as N-fixing, inclusion of which in the Integrated Farming Systems or in agro-forestry programmes can greatly revitalise soils, thereby reducing the quantities of fertilisers required. Among these the most well known are the leguminous species for their characteristic of biological fixation of nitrogen — for example, Subabul can fix 500 kg N/ha/year, safed siris 260 kg/ha/year.

These also check soil erosion and run-off, maintain soil organic matter, and improve physical, chemical and biological properties of soil. These multi-purpose trees also provide an additional source of income to the farmers, as well for risk management in the face of climate change. These practices reduce requirement of nitrogen fertilisers to a large extent. However there are allelopathic effects of some species and hence it is imperative that appropriate agro-forestry models are extended to the farmers. Multi-storied agro-forestry and silvi-horti-pastoral systems appear to be most congenial for soil conservation in the hills. India’s focus on ‘Har Medh par Pedh’, the programme for promoting agro-forestry, is a step in this direction.

Hence it is of utmost importance that national policies promote soil health, soil carbon sequestration, restoration of degraded soils and use of soils (agriculture) in a sustainable manner. The basing of these actions on evidence and science is exemplified by India’s programme of Soil Health Cards (SHCs) which has tested farm-holdings on 12 important parameters including NPK, micro-nutrients and organic carbon.

A study carried out in 2017 to assess the impact of the programme showed that even in the two years of implementation, some reduction in fertiliser use, especially nitrogen, was observed together with an increase in use of bio-fertilisers. There was a reduction in use of urea and DAP by 20-30 per cent in paddy and cotton in some States leading to decrease in cost of cultivation in the range of ₹1,000-4,000 per acre. A significant increase in yields for farmers who implemented the prescriptions was also observed. This together would result in increased incomes.

The lacunae of less awareness among farmers on use of the prescriptions and less confidence in grid-based sampling is being addressed through the development of model villages in each of the 6,954 blocks of the country, currently under way. India’s SHC has become part of the agenda in bilateral collaborations in agriculture with a number of countries. In the immediate neighbourhood, India is assisting Nepal to scale up soil-testing facilities as well as organic farming for sustainable agriculture in the extremely sensitive Himalayan ecosystem.

The writer is Additional Secretary, Department of Agriculture Cooperation and Farmers Welfare