Back R. I. Papendick1, J. F. Parr2,3 and S. B. Hornick2,3
Agricultural Research Service, U.S. Department of Agriculture, Pullman,
Washington, USA1
International Nature Farming Research Center, Atami, Japan 2 and
Nature Farming Research and Development Foundation, Lompoc, California,
USA3
Full Paper (PDF File: 81KB)
Abstract
Many problems which sustainable agriculture attempts to address such as productivity, environmental quality, food quality and farm income are often soil related and can be resolved directly by improving soil quality. Because the soil does more than just produce food. soil scientists and other agriculturists are adopting the concept of soil quality as a way to measure or account for the capacity of the soil to perform multiple functions within an agroecosystem. For agricultural ecosystems three major functions are defined: to sustain productivity, enhance environmental quality, and to support human health and habitation. Many of the problems with current agricultural systems relate to the fact that the multiple functions of the soil have been largely overlooked or ignored, especially those relating to environment and health. Soil quality can be degraded not only by soil erosion but by a number of other processes as well including acidlfication, compaction, crusting, and loss of nutrients, organic matter, and structure.
The most serious degradative processes are management-related and of these tillage, especially excessive tillage is the most destructive. Tillage of any kind results in loss of soil structure and accelerated erosion where the hazard exists. It is becoming well-documented scientifically that continuous no-till, where crop aftermath (i.e., residues) is retained on the soil surface and sowing is done with minimal soil disturbance, is the most effective approach for restoring and improving soil quality. Research and farmer experience indicate that with continuous no-till soil organic matter tends to increase, structure improves and, in time, crop yields can increase substantially due to improved water relations and nutrient availability. A major obstacle that farmers often face with continuous no-till is overcoming yield-limiting factors during the transition years, i.e., the first years of no-till following a history of conventional tillage. These are often poorly understood and may be ecologically-driven and related in very complex ways. Some of the main problems involve managing high residue levels, and increased weed and disease infestations. Farmers switching to continuous no-till must often gain new knowledge and develop new skills and techniques in order to achieve success with this different way of farming.
It would seem that there is considerable potential for nature farming and EM technologies that could help farmers overcome some of the barriers to continuous no-till. For ex-ample, it appears that EM can enhance the decomposition of crop residues. Moreover, research has shown that seed treatment with EM can stimulate germination and seedling emergence. There is also some indication that seed treatment with EM prior to planting either by a) immersing the seed for brief periods using specific EM:water dilutions or b) dusting the seed with finely-ground EM Bokashi, can reduce the incidence of soil-borne diseases and protect seedlings against pathogens. Nature farming experience and philosophy on the judicious use of crop rotations, cover crops, green manures and legumes could be invaluable in developing no-till systems. Research should also be conducted on the use of EM for plant protection against weeds and insects. Answers to these and other questions are urgently needed to provide strategies for promoting soil quality as a way to enhance agricultural sustainability for future generations.