RESEARCH PROGRESS AND NEEDS CONSERVATION TILLAGE (CLASSIC REPRINT)

Excerpt from Research Progress and Needs Conservation TillageAn in-depth understanding of the influence of tillage and residue manage ment systems on the physical, chemical, and biological components of the plant-soil environment will be an essential component in optimizing conserva tion production systems with crop yield and quality. Unfortunately, because tillage itself is a physical manipulation of the soil, much tillage research has stressed the effects on the physical characteristics of soil, only minor emphasis has been placed upon biological considerations.Tillage alone can have dramatic effects upon biological equilibria and microbial populations in soil (mccalla, Reductions in crop yield, associated with conservation production systems, have emphasized the need for a complete understanding of the biological changes in the soil environment. Research to determine the biological effects of minimum tillage and residue management will be multidisciplinary because of the necessity of studying the microbiology, biochemistry, chemistry, and physics of the plant-soil environ ment, as well as the physiology and disease and insect-vulnerability of the crop itself.An important component in the study of conservation production systems should be the characterization of the microbiology of the soil This aspect should not only involve the correlation of counts of soil fungi, actinomycetes, and bacteria with the conservation production systems. It also should include the effects of tillage and residue incorporation upon microorganisms that are responsible for such agronomically and environmentally important transforma tions as nitrification and denitrification. In specifically studying theeffects of residue management on production of phytotoxic compounds, the water - soluble and gaseous phytotoxic compounds will have to be identified. In the case where phytotoxic compounds are being produced by microorganisms, the microorganisms responsible for the