Dr Rattan Lal is not only a giant in the field of living soil, but also the author of 22 books and one of most cited scientists in the world. He has received global recognition for his work over the years. In 2007, he was co-laureate of the Nobel Peace Prize while serving on the Intergovernmental Panel on Climate Change, and in 2014 was included in the Thomson Reuters list of the World’s Most Influential Scientific Minds. In 2020, he was awarded the World Food Prize and was designated an IICA Goodwill Ambassador…
Q: When did you first know you wanted to spend your life studying soils?
My interest in soil and its management goes back to my childhood (1950s) when I was growing up on a family farm in north-western India where farming was a way of life. During those times without fertilizers, tractors, or electric/diesel pump to lift irrigation water, families’ and community’s wellbeing depended on soil and its ability to produce crops – especially so during the bad growing seasons (sub-normal rains, and infestation with locust etc.). Not only did I have the hands-on experiences with most farm operations (ploughing, puddling, seeding, weeding, transplanting, harvesting, threshing, winnowing etc.), I also faced the challenges of small landholders under the conditions of drought, high temperatures, soil hardness, compaction, crusting, low fertility and dust storms. When I had the opportunity to study at a college for BSc and MSc degrees, I had natural instinct for studying soil and learning how to manage it. That interest has been the big motivational force throughout my professional career and remains so even today.
Q: You predicted that we could decrease the land area under cultivation by 30 percent and decrease total fertilizer use by half but still double grain yields by 2100 if we improve soil quality. Are we moving in this direction? What challenges stand in our way?
Humanity practicing agriculture on 40% of all ice-free land area, using 200 million tons of chemical fertilizers, diverting 70% of all water withdraw for agriculture, and emitting one-third of greenhouse gases from agricultural operations have degraded 30% of all soils of the world – wasting 30 to 40% of all food produced and dumping it into a landfill. Yet 1 in 7 persons is undernourished, and 2 to 3 in 7 persons are malnourished. Despite all this wastefulness, there is often a call for bringing more land under agriculture to feed the world’s growing population which was 7.8 billion in 2020 and is projected to be 9.8 billion by 2050 and more than 11 billion by 2100. This wasteful extravaganza, which is also a crime against nature, must stop. We must never ever take food, land, climate, water and other resources for granted. We must learn how to use these precious and finite resources prudently and judiciously. Rather than using more than 5 billion hectares of land for agriculture we must return some land to nature. The strategy is to “produce more from less – less land, less water, less fertilizers, less emissions”. We must develop an agenda to return one-third or even one-half of the land back to nature by 2100. We must learn how-to live-in harmony with nature and develop a big buffer zone between human and other species. We must plan to have 50% of all land under natural ecosystems.
Q: Even though soil science is deeply complex, if you had to pick one simple message that you want everyone to remember, what would it be?
Soil is the essence of all terrestrial life, and soil life-support capacity depends on its health, quality or functionality. A primary determinant of soil health is its organic matter content which in most conditions (humid, subhumid and semi-arid environments) should be between 3 to 5% in the surface 20 cm layer. Soil organic matter is also the source of energy and the habitat for living organisms, which under optimal conditions should weigh about 5 ton/ha. A soil with a high biodiversity is a disease-suppressive soil. An optimal level of soil organic matter content is also essential for a favourable structure (tilth) that holds and transmits water. The One Health concept states that the “health of soil, plants, animals, people, environment and planetary process is one and indivisible”. In other words, enhancing and sustaining soil health is critical to achieving global peace and harmony. When soil is degraded and cannot produce adequate amount of food and provide essential ecosystem services, it leads to “soil refugees” which are the cause of political unrest and civil strife. Healthy soils are essential to achieving world peace.
Q: So, what practices must farmers follow to restore soil health?
The dos are residue mulching, no-till farming, growing a cover crop or forage, managed grazing, using compost and bio-fertilizers, drip sub-fertigation, agro-forestry, integration of crops with trees and livestock, recycling of all bio-waste on land, and observing the Law of Return, that is, replace everything one way or another what is removed from land. The don'ts include no burning of residues, no removal of top soil for brick making, no flood irrigation, no excessive or imbalanced use of chemicals, no puddling and flooding of rice fields.
Q: Can the process of soil restoration lead to lower yields?
Some of the improved management practices that I mentioned above may not produce as much yield during the first few seasons of transition as conventional practices. Thus, farmers must be compensated through payments for ecosystem services, which could be around ₹1200 per acre per year. We must also have a national soil protection policy. Prime agricultural land must be demarcated and protected against urbanization and other non-agricultural uses. There must be Rights of Soil or Rights of Nature.
Q: Can healthy soils mitigate the impacts of climate change?
Under natural conditions (forest, savanna, prairies, wetlands), soils are the largest reservoir of carbon (both organic and inorganic). Soil erosion and degradation makes soils a source of greenhouse gases (carbon dioxide, methane, nitrous oxide). Methane (from rice paddies, cattle and biomass burning) is 21 times more potent in causing global warming than carbon dioxide, and nitrous oxide (from fertilizers, bio mass burning) is 310 times more potent. Accelerated soil erosion by water and wind removes soil organic matter and leads to emission of carbon dioxide, methane and nitrous oxide into the atmosphere. In contrast, adoption of erosion control and better agriculture practices can remove carbon-dioxide and methane from the atmosphere. Sustainable management of soil and agriculture are a solution to global warming. India is signatory to achieving Land Degradation Neutrality by 2030. Adopting sustainable agriculture practices can help India meet its commitments.
Q: It’s always hard to translate the results of scientific research into policy and into practice. Could you talk a little bit about where you think the most forward-thinking policies are relating to changing soil quality?
US-EPA has a "Clean Air Act” (1967) and “Clean Water Act” (1972), but there is no equivalent “Soil Quality Act”. I do not know any country that has soil protection act. This is a major obstacle. Such an Act can be used in a positive manner by rewarding those farmers and land managers who adopt the recommended soil management practices. The Act can also be used to restore degraded and polluted soils. It is easier to implement the Clean Air Act and Clean Water Act by regulating point sources of pollution. But there are billions of farms globally and it is a challenge to implement it. Nonetheless, it is important to understand that it is impossible to have clean air and clean water without having high quality or healthy soils. Thus, developing and implementing “Soil Quality Act” at county, state, national, continental and global level is essential. Scientists and policymakers must work together, with the support of the private sector, to develop and implement a “Soil Quality Act” – and some countries must take a lead so that others can follow.