Mulch Tillage: Some Effects on Plant and Soil Properties

Abstract The effects of a “double‐cut plow” method of mulch tillage on fertility, as measured by soil nitrate‐N, soluble nutrients in leaf, grain yields, and nutrient content of the corn plant, and on physical properties of the soil were investigated at Blacksburg, Va. The standard 3‐year rotation of corn, small grain, and clover‐grass with mulch tillage practice during the corn year was compared with a similar rotation using conventional clean tillage practice. The percentage of N in the corn plant was lower where mulch tillage was used. The differences were significant (5% level) for high yield seasons. Percentage P in the plant was not affected by tillage method. Differences in K content of corn plant between tillage method, although usually large, were inconsistent. In general, soil nitrate‐N and soluble N‐P‐K in leaf tissue were lower during the early part of the growing season under mulch tillage. Significant reduction in yields (19 bu./A.) were obtained from mulch in 1948. This was apparently due to a similar reduction in stand. In 1949 and 1950, with planter modifications which pushed the mulch from the row, comparable yields and stands were obtained. Three‐year average yields were: mulch 73 bu./A., turn plow 81 bu./A. The 0–3 inch layer of soil under mulch showed higher aggregation, air space, percent organic matter, and percent total nitrogen than did conventional tillage. There are a number of factors which may affect the availability of nutrients where this tillage method is used. It is believed that the lower N status under mulch was due chiefly to changes in the soil microflora brought about by this tillage.