RIDGE-TILLAGE FOR CORN AND SOYBEAN PRODUCTION - ENVIRONMENTAL-QUALITYIMPACTS

Tillage practices are needed to increase agronomic stability and produ ctivity while enhancing the environment. Ridge tillage has been demons trated as an effective agronomic practice; some have described it as a miniature precision agriculture. Environmental impacts have generally been positive but the results vary, depending upon soil and climatic factors. Ridge tillage changes soil temperature and water patterns com pared to no-till and full width - moldboard/chisel plowing or disking for primary tillage. These changes lead to an improved soil environmen t for crop emergence and early growth, because of warmer soil temperat ures in cool climates and better water relations in both poorly-draine d and moderately well-drained soils. While increased soil water infilt ration in the interrow can lead to increased leaching and greater load ing of nitrates and herbicides at the bottom of the root zone, control led studies suggest that ridge tillage with precise agrichemical place ment in the ridge can provide a favorable environmental impact. Moreov er, the combined herbicide and cultivation for weed control reduces th e treated area and overall application for herbicides. Ridge tillage w as evaluated at a number of field locations of the Management Systems Evaluation Areas program to assess both agronomic and environmental im pacts. A special effort in these ridge tillage evaluations was to trac e agrichemical movement from the site of application within the soil a nd into the surficial aquifer. In most instances, ridge tillage decrea sed agrichemicals leaching and the negative environmental impact. (C) 1998 Elsevier Science B.V. All rights reserved.