寒地水稻秸秆还田配施氮素效果研究

采用大区对比的方法研究了水稻秸秆在不同处理条件下还田对水稻生长和产量以及对土壤肥力的影响。结果表明，各处理秸秆还田后对水稻产量均产生增产作用，增产范围在2.7%～10.6%。其中秸秆全量还田（500kg/667m^2）配施碳铵14kg/667m^2＋碳酸钙20kg/667m^2时水稻产量最高，达到553.4kg/667m^2，比对照每667m^2增产10.6%；其次是秸秆半量还田，配施碳铵14kg/667m^2的处理，667m^2产547.8kg，比对照667m^2增产9.5%；秸秆全量还田＋施碳铵6kg/667m^2的处理产量最低，增产率为2.7%。同一调查日期内各处理株高相近。处理4对水稻稻瘟病、胡麻斑病、褐变穗等病害的抗性明显增强，稻瘟病发病率降低20%，抗倒伏和抗早衰能力明显增强。随着秸秆还田量的增加，穗粒数、空瘪率呈递增趋势，千粒重呈下降趋势。碳铵施用量与产量呈良好的正相关，相关系数为1。处理4比处理3每667m^2增产水稻18.3kg，增产率为3.4%。

Study on the Effect of Rice Straw Return to Field and Nitrogen Fertilizer Combined Application in Cold Region

In huge area contrast experiment,the effect of rice straw treaded by different methods return to field on the growth and yield of rice and soil fertility was studied.The results showed that rice straw return to field could increase yield of rice among all treatments, the yield increments ranged between 2.7% and 10.6%. The optimum formulation with the highest yield was rice straw 500kg/667m^2 ＋ 14 kg/667m^2 ammonium bicarbonate ＋ 20kg calcium carbonate per mu, the yield attained 553.4 kg/667m^2, and increased 10.6% than the control, the second was 250kg/667m^2 ＋ 14 kg ammonium bicarbonate per mu, its yield was 547.8 kg, and increased 9.5% than the control, The optimum formulation with the lowest yield was rice straw 500kg/667m^2 ＋ 6 kg/667m^2arnmonium bicarbonate, the increasing rate of output was 2.7%. Plant height of every treatment was similar during the same period. The resistance of treatment four on rice blast, rice brown spot and bowning ear of grain was improved obviously, the incidence rate of rice blast decreased by 20%, the ability of resistant to lodging and premature senescence was improved significantly. With the increase of crop-residue incorporation, grain num- ber per spike and the shriveled seed percentage presented an increasing trend, but thousand kernel weight had a descreasing trend. And significant positive correlation was observed between the application rate of ammonium bicarbonate and yield of rice, the correlation coefficient was 1.The yield of rice treated by treatment four increased 18.3kg than that of treatment three, and the increasing rate of yield was 3.4%.