Abstract:Field observations and laboratory studies revealed that the "white soil" in Tai Lake regin was formed as a result of surface water-logging. The iron content of the whole soil and the clay fraction in the "white horizon" at a depth of from about 25 cm to 40 cm was rather low, and as a consequence the alumina/iron oxide ratio of the "White Horizon" was high as compared with other horizons. The soil differed from the "degraded paddy soil" of Japan in that it was not a result of present-time formation. The infertility of the soil was found to be due chiefly to the lack of available nitrogen and phosphorus, especially in the "white horizon". Field experiment revealed that the application of large amount of manures and fertilizers could increase the yield of rice by about three times as compared with the control treatment.

Abstract:1. Мероприятие орошения и дренажа в рисовой почве влияют на изменение состава бактерияльной Флоры.

Abstract:Es Wird eine Komplexometrische Eisen-and Aluminiumbestimmung im Boden beschrieben. Die Bestimmung des Eisens erfolgt mit Sulfosalicylsaure als Indikator. Aluminium wird durch Zugabe eines Überschusses an AeDTA-Lösung und Rüektitration mit CuSO₄- Lösung unter Verwendung von Brenzectechinviolett als Indikator bestimmt. Eisen and Aluminium mussen zuerst mit Urotropin ausfüllt verden.