Parmanand Sahu, Research Associate, under the co-operating of AICRP on EAAI, ICAR-CIAE, Bhopal
Sandip Gangil, Principal Scientist, Agricultural Energy and Power Division, ICAR-CIAE, Bhopal
Harsha Wakudkar, Scientist, Agricultural Energy and Power Division, ICAR-CIAE, Bhopal
Manish Kumar & Pushpraj Diwan, Senior Research Fellow, under the co-operating of AICRP on EAAI, ICAR-CIAE, Bhopal

Introduction
Agriculture is entering a transformative era. Although the green revolution has been successful in feeding a rapidly growing human population, it has also depleted the Earth’s soil and its biodiversity and contributed to climate change. These extractive practices are not sustainable. We must move quickly to transform agriculture by employing a suite of practices known as regenerative agriculture.

Regenerative agriculture blends sustainable innovation with tradition. As the name suggests, it focuses on the literal regeneration of the soil and the planet’s ecosystems.
Regenerative agriculture improves soil, delivers high productivity and high-quality food and helps fight climate change and restore lost biodiversity.

What is regenerative agriculture?
Regenerative agriculture (RA) is an outcome-based food production system that nurtures and restores soil health, protects the climate and water resources and biodiversity, and enhances farms' productivity and profitability.It comprises a range of techniques, supported by innovative technologies, which can combat the challenges caused by climate change by restoring the health of the soil and protecting the land’s ecosystem. Regenerative agriculture is an evolution of conventional agriculture, reducing the use of water and other inputs, and preventing land degradation and deforestation. It protects and improves soil, biodiversity, climate resilience and water resources while making farming more productive and profitable.

Goals of regenerative agriculture
  • Produce enough nutritious food for the world’s population
  • Help mitigate climate change by sequestering carbon in soil and reducing greenhouse gas emissions
  • Restore threatened biodiversity and enhance natural habitats
  • Prevent further deforestation and grassland conversion by increasing productivity on existing farmland
  • Enhance farmer livelihoods.

What are the principles and practices behind regenerative agriculture?
The agricultural sector needs to transform, and regenerative agriculture can enable this transition by building up soil organic matter and nurturing its health. But it is not a one-size-fits-all solution – instead, each unique context requires a different set of farming approaches to maximize productivity while restoring soils and biodiversity. Different regenerative practices suit different regions or even individual farms depending on the conditions, although they are underlain by a common set of principles.

Minimize soil disturbance
  • Principle: Minimizing soil disturbance benefits the soil and the climate
  • Practice: No-till or reduced-till techniques

When soil is ploughed or tilled, its structure is damaged, leaving it vulnerable to wind and water erosion and microbial decomposition. Tilling lessens the soil’s ability to retain water, devastating crops during increasingly frequent droughts. Farmers practising regenerative agriculture greatly reduce or stop tillage and instead plant seeds directly into the residue of the previous crop. With this, the soil contains more organic matter and is less prone to being blown away by wind or washed away by water.

Plants in the ground year-round
  • Principle: Year-round plant coverage prevents soil erosion and increases carbon inputs
  • Practices: Growing cover crops, double cropping
Soil health improves when crops are kept in the ground year-round. Regenerative agriculture farmers plant a different crop immediately after harvest, often alternatingcash crops and cover crops. This green cover shades the soil and the roots dig into it, increasing moisture.

Diversify crops in time and space
  • Principle: Diversifying crops in space and time supports resilience, productivity, and diversity.
  • Practices: Crop rotation, interseeding, relay planting and biodiversity strips or agroforestry.
Planting the same crops on the same fields, year after year, strips the soil of nutrients and allows pests and weeds to flourish. In regenerative agriculture, farmers rotate different types of crops over time. This helps limit pest infestations and nourishes beneficial microbes in the soil with a more diverse diet. Rotating between nitrogen-fixing crops like soybeans and nitrogen-hungry crops like corn can reduce the need for fertilizers.

Optimize the application of biological and chemical inputs or keep organic field
  • Principle: Reducing biological and chemical inputs
  • Practice: Precision agriculture or organic farming
Data-driven precision farming is a key part of regenerative agriculture. Farmers use digital tools, like soil-scanning sensors, to create detailed field maps and tailor applications of crop protection products and fertilizers. This leads to using only the optimal amount and the right type of product needed for a productive crop.

Industrial agriculture typically uses vast quantities of chemical fertilisers which leach from the soil into water systems creating harmful algal blooms. Chemical pesticides are not selective, killing beneficial insects and diminishing soil life. This forms a vicious cycle with the depleted soil and unhealthy crops becoming increasingly dependent on pesticides and fertiliser. Instead, implementing soil protection measures, crop rotation and polyculture, as discussed above, will build rich fertile soils and healthy resilient crops, minimising the need for pesticides and fertiliser. Cover crops, particularly nitrogen-fixing ones will help increase soil fertility. A diversity of crops will also attract a diversity of insects which act as a natural pest control method by preventing a single pest proliferating.

Biochar and Terra Preta
The technique of using charcoal to improve the fertility of soils originated in the Amazon basin at least 2500 years ago. The native Indians of the region would create charcoal, mix it with organic matter and broken pottery, and incorporate it in small plots of land from 1 - 80 hectares in size. Terra Preta, as it is known in this area of Brazil, remains highly fertile until today, even with little or no application of fertilizers. This is in a region of the world known for its highly infertile tropical soils.

Organic carbon, meaning carbon-based molecules that have their origin in anything that was once living, makes topsoil black or brown in colour. It is commonly known that fertile soils are black, and perhaps less commonly known that this fertility arises from the presence of organic carbon. In tropical and subtropical regions of the world, organic carbon does not tend to accumulate in soils, and so they are generally white, yellow or red in colour. The reason is that because of the heat and humidity, organic matter decomposes rapidly and directly to CO2, and hence little to no organic carbon is present in the soil, only the sand, silt, clay, stones and minerals. In more temperate regions of the world, organic matter decomposes slowly enough that it remains on and within the top layer of soil as it breaks down into smaller and smaller molecules. Some of this organic carbon decomposes fully to CO2, while some of these so called humic molecules bind to minerals and become relatively stable, enduring for hundreds to thousands of years.

Terra Preta becomes all the more remarkable when you understand that whether it was created intentionally or not, the Amazonian Indians have shown us a way to rapidly create and regenerate fertile soils.

Integrate livestock when possible
  • Principle: Livestock can help create a virtuous circle of soil health.
  • Practice: Managed grazing
Livestock – cows, goats, sheep, chickens, and pigs – are walking bioreactors, transforming plant material into rich organic matter through manure production. Whenever it is practical to integrate livestock into crop production, there are a range of benefits including increased fertility and improved soil structure. Grazing cover crops or crop residue at the end of the season helps prepare the land for the next round of seeding, without tilling.

Can regenerative agriculture reverse climate change?
Around 22% of anthropogenic greenhouse gases come from agriculture, forestry, and other land uses, according to the Intergovernmental Panel on Climate Change (IPCC).

Yet soils are one of the Earth’s most important carbon sinks, holding more carbon than all of the world’s vegetation plus our atmosphere combined. When practices that maximize carbon inputs to soils, such as planting cover crops, are combined with practices that minimize carbon losses, like no-till, soils can sequester significant amounts of carbon each year. Regenerative agriculture has the potential to transform agriculture from a source of greenhouse gases towards a net carbon drawdown.
  • Changes in farm practices could sequester nearly a billion tons of carbon dioxide around the world every year.
  • Regenerative agriculture practices applied at scale could draw down more than 10% of all anthropogenic carbon emissions into the soil over the next 25 years.
  • Global land under cultivation could store 1.85 gigatons of carbon more than at present per year, which would compensate for all the world’s transport-related emissions.
  • Turning farms into carbon sinks, reversing desertification, and preventing land conversion could together limit or even reverse climate change and safeguard the global food system.

Conclusion
While regenerative agriculture is not a solution to all our food production problems, it offers great benefits for farmers, consumers, and the environment, helping make a positive shift toward a more sustainable food system. Therefore, raising awareness about these sustainable farming practices and encouraging people to support local regenerative food production is important.

References:

1. Syngenta Group, Regenerative Agriculture. https://www.syngentagroup.com/en/regenerative-agriculture

2. Medium.com, 5 Principles of Regenerative Agriculture. https://medium.com/@amykwilson/5-principles-of-regenerative-agriculture-83d2b8786a3b

3. Biochar.com, Terra Preta. https://biochar.info/?p=en.terra_preta

4. Anthropogenic soils in the Central Amazon: from categories to a continuum

5. The Terra Preta phenomenon: a model for sustainable agriculture in the humid tropics.