Fractions of soil nitrogen during different periods of submergence and their effects on yield and nutrition of wetland rice (Oryza sativaL.)

摘要

A greenhouse experiment was conducted to study the changes in different organic fractions of soil N after application of N fertilizer as organic N alone or in combination with inorganic N. The decrease in the amount of hydrolysable NH4+and amino-acid N was positively related to mineral-N production, grain yield and N uptake, but changes in the amount of amino sugars were not related to these three parameters. The non-hydrolysable N fraction was negatively related to grain yield and N uptake. The average mineral-N production during incubation was highly correlated with both grain yield and N uptake.