Crop Responses to No‐till Management Practices on Hilly Terrain1

Abstract

AbstractManagement practices are needed that will permit economic crop production in hilly terrain without excessive soil and water losses. Field studies were conducted over a 3‐year period to determine the effects of two rates of atrazine on yield of corn (Zea mays L.) sod planted in orchardgrass (Dactylis glomerata L.) for 2 years and to determine the residual effect of atrazine on germination and growth of 16 agricultural plant species the third year. Atrazine at 2.2 and 4.5 kg/ha was applied at planting time for sod‐planted corn and compared with two different methods of growing corn using conventional tillage. Regrowth of orchardgrass in sod‐planted treatments was measured following harvest of corn. Temperature and soil water measurements were made in sodplanted and conventionally‐tilled corn over a 2‐year period. Silage and grain yields were significantly higher from sod‐planted corn than from conventionally tilled corn. No soil losses were noted in areas where corn was sod‐planted as compared to heavy losses in conventionally‐tilled corn. Soil temperatures in no‐till corn averaged about 10 C less than under conventional tillage methods, with significantly higher amounts of available soil water present in no‐till plots than in conventionally‐tilled plots throughout the growing season. Residual studies with 16 different plant species indicated very little detrimental effect from residual atrazine after 2 years of application. Growth of many plant species was significantly higher following application of atrazine.