Organic No Till overview | Food Production and Preservation | Forums

A pretty nice article on the method

Introduction

Since the advent of no-till in conventional row crop production, soil conservation and improvement aspects of no-tillage systems have attracted the interest of some organic farmers. The big question, of course, is how to do it without synthetic herbicides. The first big breakthrough occurred in the 1980s with the discovery that certain winter annual cover crops, notably cereal rye and hairy vetch, can be killed by mowing at a sufficiently late stage in their development—full head emergence with pollen shed in cereal grains, and full bloom in legumes. When winter annual cover crops at this stage of development are cut close to the ground, they generally do not regrow significantly, and the clippings form an in situ mulch through which vegetables can be transplanted with no or minimal tillage. The mulch hinders weed seed germination and seedling emergence, often for several weeks.  This strategy is sometimes called "organic no-till," although continuous no-till is usually not feasible at this time for organic production of annual crops.

In some initial experiments, the mulch effect of the mechanically killed cover crop was sufficient to delay the onset of weed growth until after the crop’s minimum weed-free period, which made postplant cultivation, herbicides, or hand weeding unnecessary (Fig. 1). Crop yields were commensurate with yields in control treatments in which the cover crop was incorporated. Tomato and some late-spring brassica plantings did especially well, and some large-seeded crops can be successfully direct-sown into cover crop residues. Such results, combined with research findings that no-tillage systems with cover crops can substantially rebuild soil organic matter and soil quality, stimulated widespread interest in developing organic no-tillage systems.

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