What is Zero Tillage? Zero Tillage is the central element in what is now widely termed Conservation Agriculture. It brings a quantum leap in crop production technology, for it brings agriculture into harmony with nature. It puts into practice ideas first propounded by Edward Faulkner in his revolutionary and best-selling book, Ploughman’s Folly, published in the USA in 1947. Faulkner had the audacity to challenge the paradigm that cultivating soil was beneficial. In a well-conceived argument, he showed that all standard wisdom used as a rationale for ploughing and working the soil was invalid.
Later, Louis Bromfield, the author of Malabat Farm and other classics, also crusaded against conventional methods of cultivation. However, all of these valiant efforts to put into practice a method of sod-seeding in a narrow strip opened by a chisel plough did not gain credibility. And it was not until the discovery of the first desiccant herbicide by a British chemical company in 1955 that the idea of eliminating soil cultivation completely began to gain expression.
Faulkner might have balked at the idea of using chemicals, yet it was the availability of desiccant herbicides that brought the most notable advances in developing Zero Tillage technology, in the USA (Phillips and Young, 1972). There was also progress in Zero Tillage in Europe, until the burning of straw in the fields was prohibited. This made planting very difficult with existing seed drills, and progress in Zero Tillage stalled. It is only now beginning to recover in this part of the world.
The Features of Zero Tillage/Conservation Agriculture
- Crop residues are distributed evenly and left on the soil surface;
- No implements are used to turn the soil over, cultivate it, or incorporate crop residues;
- Weeds and/or purpose-planted cover crops are controlled by a pre-planting application of a non-pollutant desiccant herbicide;
- A specialized planter or drill cuts through the desiccated cover and residues accumulated on the soil surface, slotting seed (and fertilizer) into the soil with minimal disturbance;
- Subsequent weed control is carried out with some pre- but mostly post-emergent herbicides, which also used in conventional tillage;
- Crop rotation is fundamental to Zero Tillage, since this promotes adequate biomass levels for permanent mulch cover; it also assists in the control of weeds, pests and diseases, as well as in improving the physical condition of the soil.
- Soil erosion is reduced by about 90% and soil biological activity and bio-diversity are maximized.