Soil has been described as “the fragile, living skin of the Earth” and yet its’ fragility has often been ignored in the continuous use of tillage techniques in modern agriculture. Tilling is the process of preparing land for growing crops by mechanically modifying soil structure. Other names for tilling include digging, plowing, cultivation, etc. This technique was adopted by farmers 10,000 years ago for a number of reasons. However, years of research and farming show that even though this method has some advantages, negative consequences and drawbacks of it are also significant. Therefore, over time, less destructive alternatives have emerged such as reduced tillage and no-till techniques, which can be generalized by the term conservation agriculture. Let’s look a little closer at some factors, which make zero-tillage a sustainable alternative to conventional tillage (CT) practices!
Plowing, or CT is mainly done to aerate and loosen soil, bury weeds, and mix organic matter into the soil. Tilling indeed helps to aerate soil organic matter, which in turn releases nutrients required for plant growth, but when exposed to air, organic matter oxidizes, thereby reducing its’ content in soil, unless additional organic matter is returned as residues, compost, or other means. CT allows for looser soil, but it becomes compacted below the depth of plowing from the passage of plow sole and tractor wheels.
Complete burial of weeds is possible under CT, but at the same time, problems with weeds for zero-tillage in many cases can be considerably alleviated by permaculture. Maintaining soil micro-organisms and microbial activity allows suppression of weeds by biological agents. No-till also reduces soil erosion, runoff, and loss of particulate P. In terms of the footprint on the environment, an application of CT is associated with much higher CO2 and other greenhouse gas emissions from working machinery and oxidizing organic matter than no-till. The practice of no-till is an excellent water-saving technique too, due to increased infiltration, reduced evaporation and increased soil water storage. Economically, zero-tillage is cheaper, because of reduced use of machinery, fuel, and human labor. Some equipment may still be required at large scales of conservation agriculture to promote seed germination planted into soil that is not tilled and with residue mulch on the surface.
Thus, even though no-till or reduced tillage has many advantages over CT, the success of its’ application depends on many factors such as climatic conditions, crops or plants to be grown, soil type, etc. Crops yields are often lower immediately after adopting no-till, taking about three years for soil structure to improve. Generally, extensive studies of crop yields in different countries conclude that no-till provides similar or higher yields of some crops as compared to CT.
As we can see, zero-tillage is nondestructive, environmentally-friendly, and a much less expensive method of soil preparation for seeding and transplanting, which has been in use for many years; however, many farmers and gardeners all over the world are still reluctant to shift from CT to no-till. Therefore, more research and governmental/municipal support is required to convince farmers to adopt no-till approach at both small and large scales. In some cases, a slow transition from CT to no-till can be implemented through reduced tillage practices until required confidence has been built and skills acquired to completely eliminate plowing. More research is required specifically on how different tillage practices affect yield. The situation is less clear on this than on financial benefits of the transition to conservation agriculture. Farmer’s support can be in form of financial incentives, educating sessions, increasing availability of equipment, etc. The soonest adoption of conservation agriculture principles wherever possible is imperative to achieving sustainability since no-till is the first step towards permaculture allowing to cultivate perennial plants both in the city and on a farm.
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