水稲畦立栽培に関する基礎的研究 : (第1報) 畦の地温と灌漑水温について

抄録

In this study, authors examined physical and chemical properties of soils in ridges, on which rice plants were planted (the ridge culture plots), in comparison to those in the usual paddy fields (the level culture or the control plots). Items examined were as those : temperatures of soils and irrigated water values of pH and Eh, contents of carbon-dioxide and two forms Of nitrogen e.g. NH₃ and NO₃. This report deals only with temperatures of soils and irrigated water. These experiments were conducted in the farm of Kyoto University, having sandy loam soil and a local variety named "Kyoto Asahi No.5" was used. The results were as follows : i) The maximum temperature of soil in the ridge plots exceeded that of the controls, but the minimum and mean temperatures of the formers were lower than those of the latters, as far as this experiment went. Then it means that soil temperature fluctuated more widely in the ridge plots than in the controls. This tendency was observed throughout the whole periods of plant growth; especially, in August it was most striking. ii) Temperatures of irrigated water in both plots closely parallel to the soil teperatures, however differences between two plote were hardly recognizable.