As of this writing, regenerative agriculture still does not have a formal definition, and is usually described as a set of farming practices that can help reverse climate change by rebuilding soil health. In most definitions, no-till is one of the first practices mentioned when illustrating what regenerative agriculture entails.
Tilling is an old, established practice in traditional farming. It refers to agitating and loosening soil in preparation for planting, and encompasses human-powered methods such as hoeing and shoveling, and animal and machine-powered methods such as ploughing. The purpose of tilling is to make the soil easier to plant in, more evenly mix nutrients within the soil, and destroy weeds prior to planting.
So why is this ancient agricultural practice under fire as an environmentally damaging process?
By overturning soil, tilling exposes organic matter such as plant roots and microorganisms to the air, where the carbon of the organic matter reacts with oxygen to release carbon dioxide into the air. Tilling also disrupts the soil structure and removes crop residue from the soil surface, decreasing water absorption and leading to soil erosion.
In contrast, no-till and minimal till practices allow healthy soil structures with greater water absorption to develop, which reduces the amount of water usage per acre. No-till also supports the maintenance of beneficial communities of soil organisms. With greater soil diversity from these communities of organisms, no-till farms are postulated to support higher yields, more nutritious crops, and enhance greater carbon sequestration within the soil.
Additionally, no-till means that farmers can perform fewer passes of their fields, saving on labor and fuel costs. In 2016, the USDA published a report estimating that conservation tillage, meaning at least one of a field’s rotated crops is produced with reduced tillage, had been adopted on~86% of US cropland acres, resulting in 9.1 million tons of CO2 emissions reduced per year. For scale, the USDA compares this reduction level to the amount of annual CO2 emissions from1.9 million passenger cars.
No-till and minimal tilling has generally been accepted in the US as on-net beneficial, both for the environment as well as for farmers in terms of yield and cost. Conservation tillage has already been widely adopted, and no-till adoption has also greatly increased in the last decade, with ~37% of 104 million tillage-reporting acres using continuous or rotational no-till, according to the USDA’s 2017 survey. A few barriers to greater adoption include the need to invest in no-till equipment, and the need for greater education on how to successfully introduce no-till. For example, no-till farmers need to learn alternative methods for weed control, and can benefit from also introducing cover cropping and crop rotation to reduce any initial loss in yield from switching to no-till.
Hopefully, as we make continued advancements in no-till practices, we can make it easier and more appealing for farmers to convert more acres into continuous no-till cropland.
