Changes in physical properties of clayey soil in soybean [Glycine max]-barley [Hordeum vulgare]-cabbage [Brassica oleracea capitata] sequences on upland fields converted from paddy
2003
Adachi, K. (National Agricultural Research Center, Tsukuba, Ibaraki (Japan)) | Yoshida, S. | Hosokawa, H.
Abstract Soil physical properties, such as macropore volume, soil water content at -3.1kPa(pF1.5) matric potential, and the liquid limit of soil, were measured after harvest time for 4 years in samples of plowed layer soil and subsoil from 4 clayey-soil upland fields that had been converted from paddy fields. The cropping system of the fields was soybean-barley-cabbage. The fields differed in their underdrainage conditions. The soil's physical characteristics were considered by analysis of variance with the year and field as factors. The results were as follows: 1. In the plowed layer, variances in many of soil physical properties depended significantly on the year at the 0.1 probability level. 2. In the subsoil, variances of many soil physical properties depended significantly on the field condition at the 0.1 probability level. 3. Macropore volume and dry bulk density of soils differed markedly according to cultivation management and rainfall conditions. Also, the year-dependent effects on macropore volume and dry bulk density of soils differed depending on the crop. 4. The year-dependent effects on soil water content at -3.1kPa (pF1.5) matric potential and at a liquid limit of soil sampled after harvesting different crops during the 4 years were similar from crop to crop. The year-dependent effects decreased as time after the conversion from paddy fields increased. This phenomenon was considered a long-term change accompanying the drying of the soil.
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