INFLUENCE OF REDUCED TILLAGE SYSTEMS ON DRY BEANS (PHASEOLUS VULGARIS L.) GROWN IN DIFFERENT CROP RESIDUES.

摘要

Dry beans (Phaseolus vulgaris L.) are generally planted by conventional tillage. Many reduced tillage systems have been developed for field crops, but little researched for dry beans. A three year study was conducted on the effect of growing dry beans in different tillage systems. Three cultivars - Midnight (black turtle soup), Redkloud, and Redkote (light red kidney's) were planted into three tillage systems - conventional (moldboard plow), minimum (chisel plow) and no-till in three crop residues - alfalfa (Medicago sativa) corn (Zea mays) and small grains.;In corn residue, yields and morphology did not differ among tillage systems. In alfalfa residue plots in conventional tillage yielded the highest and no-till plots the lowest. In two out of three years, in small grain residue, plants in conventional and minimum tillage did not differ in yield, but both yielded higher than no-till. Morphologically, plants in alfalfa and small grain residue had few differences between them. However, plants in no-till were generally smaller with fewer pods or seeds than in the other two tillage systems.;The soil moisture data were not consistent over the three years. In 1981 there were no soil moisture differences. Conventional and minimum tillage plots during 1982 had more available moisture than no-till plots and the opposite was observed in 1983.;Soil temperature differences were observed each year, but were not consistent. The differences were generally less than a 1 C with conventional or no-till plots being the warmest. Soil temperatures were warm enough throughout the growing season that plant growth and yields were not affected.;Experiments were conducted for yield components, plant morphology, soil moisture and temperature, foliar fertilization and weed control.;No-till soils were more difficult to penetrate especially in the top seven centimeters of the soil profile than conventional or minimum tillage soils. Tillage systems did not differ in resistance to uprooting and few differences were observed in root weights.;Foliar applications of fertilizer only increased yield in corn residue in 1981. There were no differences among tillage systems in 1982. Among the herbicides in alfalfa residue, alachlor + linuron and metolachlor + dinsoeb resulted in the highest yields in 1981 and 1982.