Soil compaction on upland rice

A greenhouse experiment was conducted with the objective to evaluate the ef fects of soil compaction on two upland rice genotypes grown in a Dark Red L atosol with loam texture, having densities of 1.2, 1.3, 1.4, 1.5, 1.6 and 1 .7 g cm(-3). Soil density values were created artificially at 0-20 cm soil depth using plastic tubes of 24.4 cm of diameter. Soil water potential was maintained at -0.035 MPa. Treatment effects were evaluated 40 days after se edling emergence using the shoot dry weight and the root system as paramete rs. Results obtained for both cultivars indicated that shoot growth was dec reased by increasing soil density beyond 1.2 g cm(-3) and also that root th ickness increased with increasing soil density. Additionally, superficial s oil compaction reduced the amount of roots present at 0-20 cm soil depth as well as at 20-40 cm.