Soil – Where our food begins

Dr. Chinmoy Kumar Sarma

Soil and human health are interrelated. Many people often think of active exercise program, good medical care, wise food choices and proper sanitation for their good health, but very few probably think about soils. Facts indicate that there is need to pay more attention on the correlation between soil and human health in health related research. But the group that actively recognizes soil important to human health is still in the minority. In the ancient world, many people believed illness as punishment from the gods; later on, some could realize that the natural world including soil played a role in human health.

yellow and green leafed trees under cloudy sky

Production of sufficient amounts of food, adequate nutrient content in the food products, and the exclusion of potentially toxic compounds from the food products are the key components of quality food production and food security. Noted agricultural scientist M.S. Swaminathan said “Soil anaemia also breeds human anaemia. Micronutrient deficiency in the soil results in micronutrient malnutrition in people, since crops grown on such soils tends to be deficient in the nutrients needed to fight hidden hunger.” It is estimated that 95% of our food is directly or indirectly produced on our soils.Healthy soils produce healthy crops that in turn nourish people and animals. The ability to produce nutritious crops in sufficient amounts depends on soil properties and conditions. Soil is a major source of nutrients and it is now proved that many essential human nutrients are present in the soil and are passed on to humans through the food chain. Out of the approximately 29 elements considered essential for human life, 18 are either essential or beneficial to plants and are obtained from soil, and most of the other elements can be taken up from the soil by plants. Soil also influences human health through human contact with chemicals, heavy metals or pathogens that have the potential to negatively impact human health. Soils that contain substances such as heavy metals, which may be toxic to humans, can pass those substances on to humans through crop produces which are consumed as food. Sometimes human life is also affected due to consumption of plants and animals that have accumulated molecules of pollutants over a period time even though soil itself does not contain enough pollutants to harm human life.

eye level photo of cultivated land — Photo by Jan Kroon on Pexels.com

Soil degradation is a major problem worldwide and studies revealed that approximately 33% of our soils are facing moderate to severe degradation which has made soil gradually unsuitable for crop production. Over the last 50 years, there has been increasing pressure on our soil resource due to increasing demand for food and advances in agricultural technology. Decreased soil organic matter content, loss of soil structure, loss of soil through wind and water erosion, development of acidic, saline and sodic soils, and soil contamination with pesticide residues and heavy metals are some major issues which are often linked to soil degradation. In India, use of chemical pesticide is far lower than in some developed countries; however, the problems of pesticide pollution, pesticide residues and human exposure are very significant in our country mainly because of poor knowledge in pesticide use and application techniques, ignorance about the environmental implications of pesticides and injudicious application of pesticides. Unfortunately, India is one of the few remaining countries still producing and using some of the pesticides which are banned in some other countries. The pesticide share across agricultural crops were 45 percent in Cotton followed by 25 percent in Rice, 13 – 24 percent in chilli/vegetables/fruits, 7 – 8 percent in plantations, 6 -7 percent in cereals/millets/oil seeds, 2 – 3 percent in Sugarcane and 1 – 2 percent in other. Soil in urban areas also gets polluted with organic chemicals as a result of industrial activities, sewage and solid waste dumping, coal burning, motor vehicle emissions etc. A study revealed that improper sewage sanitation was a problem for approximately 40% of the world’s population, and millions of people die every year from water-borne diseases. A major way that soils influence human health is through their ability to remove contaminants from water. Contaminants are removed by soil through physical capture as the water moves through pore spaces, through chemical sorption to solid surfaces, and through biodegradation carried out by microorganisms living in the soil

The quality and health of soil determine agricultural sustainability, environmental quality and as a consequence of both plant, animal and human health. A healthy soil has the ability to perform or function according to its potential and soil health can be improved by proper management practices and land-use decisions that consider the multiple functions of soil and that take into account that soil is a living entity. There are needs to have holistic production management systems that promote and enhance agro-ecosystem health that are socially, ecologically and economically sustainable to protect our soils while maintaining high productive capacities.Enhancing resilience in soil is vital for crop production and soil health is the key property that determines the resilience. Building up of soil organic carbon, controlling soil loses due to erosion and improving water holding capacity of soil enhance resilience in soil. Incorporation of crop residue into the soil instead of burning, addition of organic matter through farm yard manure, composting, vermi-composting, green manuring etc. are important for improving organic carbon content in the soil. Balanced use of fertilizer, selection of right type of fertilizer and improved methods of fertilizer application based on crop requirement as well as soil and weather condition are very much crucial for getting good response from the applied nutrients.

(Dr.Chinmoy Kumar Sarma, Principal Scientist, Mob – 9957130225)