Axle load and tillage effects on the shrinkage characteristics of a MollicOchraqualf in northwest Ohio

Cracking due to soil shrinkage is a complex process whose effect on soil pr operties, crop growth and water quality are not adequately understood, The intensity of cracking depends on soil characteristics and management. The e ffect of three axle loads and three tillage methods on shrinkage characteri stics and cracking behavior were studied for a heavy-textured lake bed soil in northwest Ohio. The three axle load treatments were 0, 10 and 20 Mg, an d the three tillage treatments were no till (NT), chisel plowing (CP) and m oldboard plowing (MP). Cracking area increased from 1.75% in July to 12.27% in September, was maximum in the NT treatment, and increased with increase in axle load. The no till and 30 Mg axle load caused significantly higher cracking than other axle load and tillage treatment combinations. Shrinkage of compressed soil cores under laboratory conditions showed that a bulk de nsity of 1.5 Mg/m(3) had the lowest total shrinkage volume. A combination o f no till and heavy axle load increased the cracking area and accentuated a dverse effects on soil structure. (C) 1999 Elsevier Science B.V. All rights reserved.