紫云英和油菜不同时期翻压对土壤培肥效果的影响

【目的】探寻紫云英和油菜的最佳翻压时期，为提高紫云英、油菜的综合利用效率提供理论依据。【方法】2009～2010年，按作物进行翻压的不同时期设5个处理（紫云英盛花期、紫云英结荚成熟期、油菜盛花期、油菜成熟期和空白对照）， 测定作物的鲜、干物质量，并探讨紫云英、油菜不同还田方式对土壤的培肥效果及经济效益。【结果】紫云英和油菜在盛花期后鲜产量逐渐降低，相应的干物质量呈上升趋势。不同翻压处理对土壤培肥效果影响不同，紫云英盛花期翻压土壤对土壤有机质含量影响最显著，相比基础土壤提高6.6%。紫云英和油菜翻压对后作水稻均有极显著的增产效果，其中紫云英盛花期翻压处理水稻产量最高，达9244.5 kg/ha。油菜成熟期翻压处理的利润（6696元/ha）最高，产投比为2.49∶1.00，其经济效益最优。【结论】土壤培肥效果和经济效益分别以紫云英盛花期翻压处理和油菜成熟翻压处理最优。

Effects of Astragalus sinicus and rapeseed manure application at their different growth stages on soil fertility improvement

Objective]The aim of this experiment was to find out the best applying period for Astragalus sinicus and rapeseed manure in the soil to sustain the productivity of soil and enhance their application.Method]During 2009 and 2010,5 manure application treatments were conducted at full-bloom stage and pod maturity stage of Astragalus sinicus and rapeseed,and blank control(no manure),respectively.The fresh and dry matter contents were measured in all treatments.Further,the influence of different field-returning methods of Astragalus sinicus and rapeseed plants on fertility improvement of soil was also investigated,and economic benefit was worked out.Result]Fresh yield of Astragalus sinicus and rapeseed dropped gradually after full-bloom stage,however dry matter content increased.The effect of manure application on soil fertility conditions varied under different application methods.The organic matter content was recorded as the highest(6.6% higher than basic soil)when soil was plowed at the full-bloom stage of Astragalus sinicus.Applying Astragalus sinicus and rapeseeds manure significantly increased the yield of rice,and the highest yield(9244.5 kg/ha)was recorded in Astragalus sinicus plowed at the full-bloom stage.The economic benefit was the highest(6696 Yuan/ha)when the soil was plowed at the maturity stage of rapeseed,with the input/output ratio of 2.49:1.00.Conclusion]The highest increase in soil fertility was observed when the soil was plowed at the full-bloom stage of Astragalus sinicus,while the overall benefits were maximum when fields were plowed at maturity stage of rapeseeds.