Looking Beyond Soil Chemistry

Did you know that the pesticides residue in your food can develop Attention Deficit Hyperactivity Disorder in your children? Or that the global food demand is going to go as high as 98 percent by 2050? That’s right, we are reaching the pinnacle of food insecurities and environmental disaster. There will be no turning back for a course correction if we do not pause now and check where it all went wrong.

As we all know the first post-Green Revolution phase (from late-1960s to mid-1980s) was marked by heightened productivity from otherwise poorly yielding land through the intensification of chemical and machinery inputs. Prior to this period, the Indian farmer relied on traditional and natural methods of crop cultivation without an in-depth understanding of the requirements to maximize land productivity. The second post-Green Revolution phase (beginning the mid-1980s) was marked with high input-use and a contrasting reduction in productivity.

A closer look at the facts & figures brings to light that in actuality, we are still lagging behind the world despite of having more favourable climate and much more fertile soils. Despite being the top producer of Bengal gram in the world, India imports Bengal gram from other countries to meet its heavy domestic needs. China, the No. 1 producer of wheat in the world, beats India by a huge yield gap of 31 million metric tonnes. These patterns are indications that there is a dire need to look at increasing land productivity.

Our soil, one of the most prominent reasons that life is possible on this planet, is particulate surface material made-up of various minerals, as well as organic matter. Soil supports & nourishes plant’s and animal’s life by providing it with nutrients. The ancients changed their fates and ours when they evolved from hunter-gatherers to cultivators of the land. Over time, our chemistry with soil has evolved and helped form the foundation of our thriving civilization on this planet. From tiny unicellular algae to complex vascular plants, almost all flora need soil for their development.

All soil present on Earth is a mix of three components: clay, silt, and sand. These components directly reflect soil properties such as water holding capacity and nutrient levels. Thus, playing a crucial role in agricultural practices. It is necessary for any farmer to take into account soil composition to ensure successful yields. Organic matter in the soil is the repository of nutrients formed from decaying material in soil. It is found in the top layer of soil, where root growth starts. Based on different proportion of each of the elements, soil is classified as loamy, sandy, silt, clay, peat and chalk, loam soil being the ideal soil type.

Try googling ‘importance of soil’. The first line that appears says, ‘Soils are essential for life’ (Trust me I did it too!). Soil is a medium in which plant thrive & grow. Minerals, gases, and water rest within the interstitial spaces and constitue them. Not only plants, but even biodiversity of microbes and insects find home in the soil. In agriculture, soil is the basis of a good cultivation or a bad one. It is undeniable that many a biotic factors also dictate the fate of a cultivation. However, having a fertile soil is still a necessity. In the course of adapting newer agrochemicals and hybrid seeds, we have not realised the effect of these agrochemicals on soil. The life of soil, i.e., its biology is severely impacted due to these chemical inputs. Soil microbes have been an in-dispensable part of the soil. They facilitate the movement of nutrients from soil to the plant system, thus enhancing immunity and has also kept the plants protected from diseases and abiotic stress.

Understanding the importance of soil, Governemnt of India launched a Soil Health Card (SHC) scheme in 2015. It aims at delivering SHC to all farmers in India. SHC is a report of the soil makeup and gives information on 12 parameters viz. - pH (soil reaction; acidity/alkalinity of the soil), total dissolved salts, organic carbon, phosphorous, potash, and minor nutrients like sulphur, magnesium, calcium and micro-nutrients, including zinc, ferrous, manganese and cop-per. Soil Health Card just informs you about the physical & chemical properties of the soil, but contains no information on the third pillar of soil health, which is its biology. No matter how balanced the soil is in terms of its nutrient values, it does not make the land fertile if it has poor soil microflora.

In recent years, scientists, governments, and even farmers have realised the impact of excessive use of chemicals and are now promoting organic farming techniques. Concepts like composting, vermicomposting, usage organic manure are promoted by Government. This not only cuts cost of cultivation, but also helps in farm waste management. The lacunae in these techniques is that, the farmers are un-sure with the kinds and number of microbes being seeded in the soil. Soil microbial analysis reflect that population of silicates, potash solubilisers and even of actinomycetes is poor. There is lack of a wholesome approach in soil enrichment techniques. It is important for farmers and agriculturists to adapt technologies, which are a complete solution in improving soil microbiology and are not just specific to certain issues. If we want to ensure food security and meet the accrescent food demand, it is time that we start looking beyond soil chemistry.