Studies on the improvement of drainage and soil management of drained paddy field for upland crop cultivation
Kitada, K.; Shioguchi, N.; Maruyama, T.
Bulletin of the Ishikawa-Ken Agricultural Experiment Station 13: 39-54
1985
Accession: 006517640
Appropriate measures for stabilizing high productivity of upland crops and mechanized cropping system in the upland field converted from poor-drained paddy field were investigated. It was found to be basically necessary to drain surface water smoothly by open dutch and to improve top soil drainage ability by main underdrain and sub-underdrain. Changing the location of the mole drain every year promoted the permeability of the field soil and improved the soil structure. Also application of the crude organic matter (ex. barley and wheat straw) was effective for both raising the porosity of the top soil and increasing the soil fertility. When poor-drained paddy field was converted to upland field, the content of ntirgen and carbon markedly decreased in the soil, especially the high level of the soil fertility in the preceding paddy field was reduced. The character of both soil moisture and available moisture decreased after conversion. Therefore, the application of organic matter was found to be positively important for increasing the soil fertility. Deep tillage expanded the depth of the top soil and the growth of barley and soybeans became vigorous. But in case the fertility was poorer in the subsoil than in the top soil, it was important to increase the plowing depth gradually year after year as the fertility was improved.