紫云英还田对水稻产量、土壤团聚性及其有机碳和全氮分布的影响

Effects of Planting Chinese Milk Vetch on Rice Yield,Soil Aggregation and Distributions of Its Carbon and Total Nitrogen

采用田间试验方法,探讨紫云英-有机肥配施对土壤团聚结构、有机碳和全氮分布及水稻产量的影响。试验设置了有机肥1 500 kg/hm2+0 kg/hm2紫云英翻压量(CK)、有机肥1 500 kg/hm2+紫云英翻压量30 000 kg/hm2(B1)、有机肥1 500 kg/hm2+紫云英翻压量45 000 kg/hm2(B2)和有机肥1 500 kg/hm2+紫云英翻压量60 000 kg/hm2(B3)共4个处理。结果表明,翻压紫云英未显著提高大团聚体的含量,却明显提高了团聚体稳定性,改善了土壤结构,且团聚体稳定性与土壤有机碳含量呈正相关;随着紫云英翻压量增加,水稻生育期逐渐延长(CK<B1<B2<B3),且B1、B2和B3水稻产量比CK分别提高了19%,38%和57%,水稻产量与团聚体稳定性呈正相关;翻压紫云英对团聚体有机碳和全氮含量的影响不明显,但不同粒径团聚体内有机碳含量和碳氮比随粒径减小而降低。因此,在施有机肥的基础上,配施紫云英能有效改善土壤结构和提高稻米产量。

This study aimed to investigate the influences of applying organic fertilizer combined with different amount of Chinese milk vetch（Astragalus sinicus）on soil aggregation,distributions of organic carbon and total nitrogen of aggregates,and rice yields.Four fertilizer treatments were established：organic fertilizer without Chinese milk vetch（CK）,organic fertilizer plus Chinese milk vetch（30 000 kg/hm2）（B1）,organic fertilizer plus Chinese milk vetch（45 000 kg/hm2）（B2）,organic fertilizer plus Chinese milk vetch（60 000 kg/hm2）（B3）.The results showed that treatments applying Chinese milk vetch did not significantly increase macroaggregates,but obviously enhanced aggregate stability and improved soil structure.The aggregate stability was positively correlated with soil organic carbon.With the increase in Chinese milk vetch applied,the rice growth stages became longer（CKB1B2B3）,and compared with CK the rice yields of B1,B2,and B3 increased by 19%,38%,and 57%,respectively.The rice yield and aggregate stability had a positive correlation.Organic carbon and total nitrogen of the same aggregate size were hardly influenced by treatments applying different amount of Chinese milk vetch,whereas both organic carbon and C/N ratio decreased as the aggregate size decreases.In conclusion,based on the application of organic fertilizer,adding Chinese milk vetch could improve soil structure and increase the rice yield.