Improvement of Salt-affected Soils by Deep Tillage

— Part 2: Large-scale Field Tests in a Sodic Soil (Solonetz) Region —

抄録

A deep tillage method was tested for soil improvement of salt-affected soils. Capillary rise of groundwater was cut off by the deep tillage, which made a coarse layer in the subsoil. This paper deals with large-scale field tests constructed by a four-stage subsoil plough in a sodic soil (solonetz) region. The results showed that the deep tillage down to the subsoil proved positive for the improvement of the solonetz soil. In the deeply tilled field, the grass height and density of cultivated natural pasture were much greater than those in the conventional (subsoiled) field. In the subsoiled field, the grasses were growing at the areas on the subsoiler channels, but their grass height was much shorter than in the deeply tilled field. At the undisturbed areas between the subsoiler channels, the grasses could not survive at all.