稻田中肥料流失量之觀測

Abstract

利用滲濾計觀測龍潭紅壤及溪湖石灰質粘板岩沖積土在水稻栽培期間之氮素流失情形。結果示第一期作期間之排水量比二期作多兩倍上下，在紅壤區第一期平均66.1cm，第二期平均29.5cm；石灰質粘板岩沖積土則分別為31.9cm及18.9cm。氮之流失量紅壤第一期平均3.21kgN/ha，第二期為0.16kg/h。；石灰質粘板岩沖積土則分別為0.75kg/ha及0.25kg/ha。 Losses of nitrogen in the drainage water from paddy soils were determined in lysi-meter studies. The soils used were a latosolic and a calcareareous slate alluvial soils. The results indicate that the amount of drainage water was larger in the first crop season than that in the second, for both soils studied. For the latosolic soil, the amounts were on the average, 66. 1 cm for the first crop and 29.5 cm for the second; and for the calcareous slate alluvial soil they were 31.9cm and 18.9cm, respectively. The amounts of nitrogen lost in the drainage water were on the average 3.21 kg/ha and 0.16 kg/ha, respectively, for the first and second crops on the latosolic soil; and 0.75 and 0.25 kg/ha, respectively, for the calcareous slate alluvial soil.