Influence of the rice crop on the loss of nitrogen gas from water-logged soils

Abstract

The investigation shows that when ammonium sulphate or oil cake was applied to cropped rice soils 4 weeks after transplantation, a considerable amount of the added nitrogen was lost as gas. This loss, however, was less than the loss that took place when the crop was absent. Placement of ammonium sulphate 3 in. below the soil surface reduced the loss of nitrogen, but did not significantly increase the crop yield. Gases evolved from cropped rice soils, whether unmanured or treated with ammonium sulphate, were free from hydrogen and contained practically no methane, while those formed in the uncropped soil under similar treatments contained large volumes of these two gases.

Availability of Ammoniacal Nitrogen to Lowland Rice as Influenced by Fertilizer Placement1

“…( ± 0.5 em. ), during a 14-day period after flooding, are given in figure 1. The mean oxidation-reduction potentials were corrected to pH 5.0 which approximates the average soil reaction at this experimental site.…”

“…Losses of nitrogen by this mechanism varied with the source of n.itrog~n used, time and method of application, and the soil physicochemical conditions. These studies have led to the practice of deep plowing of ammonium nitrogen before flooding as well as ball placement shortly after transplanting for the fertilization of rice (1,2,3,8).…”

Effects of Manurial Treatments and Times of Planting on Rice Production in Different Soil Types in West Bengal1

“…over the control yield of 23.9 mds. per acre (table 5). The increase amounted to 28.4% over the control and was highly significant.…”