Effects of application of pretreated rice straw on soil nitrogen supply and nitrogen uptake by winter wheat

Pot experiments were carried out to study the effect of application of chemically pretreated rice straw (TS) on soil N supply and N uptake by winter wheat in sandy fluvo-aquic soil. Results showed that the amount of cellulose, semi-cellulose and the silicon dioxide was decreased after the rice straw was pretreated. However the water-soluble matter of the pretreated rice straw was increased. Compared with control (CK), application of the pretreated rice straw combined with inorganic fertilizer could increase soil microbial biomass N by 232.3% and mineral N by 66.0% on average during the whole growth stage of the winter wheat. Dry weight of the winter wheat and N absorbed by the wheat were also increased by 56.3% and 124.3% on average, respectively. But there was not so remarkable effect on the supply of available N of the soil in the pots and N uptake by winter wheat in the treatments with application of untreated rice straw as those treatments applied with pretreated straw. In conclusion, it was more efficient that combined application of pretreated straw with inorganic fertilizer could improve soil N supply modes and increase wheat yield and nitrogen use rate.