紫云英腐解对土壤速效养分动态变化和单季稻产量的影响

为明确紫云英翻压后轮作单季稻对水稻生长和产量的影响，在种植和不种植单季稻的条件下，以紫云英为单一肥源，研究了翻压75 000 kg·hm-2高量紫云英鲜草后土壤速效氮、磷、钾养分的动态变化和对单季稻产量的影响。结果表明，紫云英翻压腐解后不轮作单季稻条件下，养分释放对土壤速效氮、磷、钾养分的动态变化影响结果不一，对土壤速效磷的影响时间最短，一般不超过20 d，对速效氮和速效钾的影响时间较长，分别达到120和150 d左右。种植单季稻后，水稻根系吸收养分对土壤速效钾和速效氮含量的变化影响比较明显，对土壤速效磷含量影响不大。以紫云英为单一肥源与不施化肥处理比较，收获期单季水稻稻秆和稻谷产量都显著提高。

Effects of Chinese milk vetch decomposing on soil available nutrient dynamic changes and yields of single season rice

Effects of decomposing and ploughing Chinese milk vetch （CMV） under soil on growth and yield of succeeding single-season rice were studied. Available N，P and K in the soil，together with the rice yield，in the soil with 75 000 kg·hm-2 decomposed CMV as the only manure were detected. The results showed that the nutrients released from decomposed CMV could differentially affect the dynamic changes of N，P and K releasing in soil without succeeding single-season rice，i.e. P in no more than 20 d，N in about 120 d，and K in about 150 d. After planting with single-cropping rice，nutrient-sorption by the root had a significant effect on available K and N content，but not on available P content. Compared to using no chemical fertilizer in the field，planting CMV and using the decomposed substances as the only manure in the field could significantly increase the yields of straw and rice.