Chemical Properties of Soils in the Farm Attached to Faculty of Agriculture, Yamaguchi University

The chemical properties of soils in the farm attached to Faculty of Agriculture, Yamaguchi University were examined. The topsoils and subsoils of 4 paddy fields, 2 orchards and 3 forage crop fields were analyzed for mechanical compositions, pH, exchangeable bases, CEC, macro and micro nutrients and clay minerals. The soil textures were LiC (mainly upland field) or CL (mainly paddy field). Except for a field of special conditions, soil reactions of all fields were neutral reflecting succesive liming. Careful attention to overliming would be required hereafter. The topsoils of all fields were lower in organic carbon, total nitrogen and available nitrogen. More application of organic materials is indispensable to improve the farm land fertility. In the base status, the forage crop fields were conspicuous for the low available potassium contents. Available molybdenum contents were rather low for all fields. Available boron and manganese contents were fluctuated among the fields from deficient to proper amounts, and the higher values were seemed to be resulted from the residual effects of the FTE fertilizers (BM-fused phosphate) applied before. There were no specific problems on phosphorous, copper and zinc. All the clay fractions were composed mainly with kaolin minerals, mica and hydroxy-Al interlayered vermiculite. It indicates that the cation exchange characteristics of clay fractions are exclusively pH-depending and ion-selective.

Soil chemical property

farm land fertility

micronutrients

soil clay minerals