Effects of erosion restoration measures on aggregate component and available nutrient in the red soil | 侵蚀修复措施对红壤团聚体组成及养分的影响

Chinese. 摘　　要：以鄂南侵蚀红壤为研究对象，采用花生-小麦轮作模式，在侵蚀小区实施结构改良剂（聚丙烯酰胺，polyacrylamide，PAM）、稻草覆盖、带状牧草及其组合措施，研究其对红壤水稳性团聚体组成（〉4．00、2．00～4．00、1．00～2．00、0．50～1．00、0．25～O．50mm）、土壤有机质及速效养分的影响，结果表明：稻草覆盖极显著地提高红壤1．00～2．00和2．00～4．00mm的水稳性团聚体含量，且花生季后土壤速效K的含量明显提高，而小麦季后红壤的有机质和速效K含量都有提高，但提高幅度各有不同。PAM以及PAM和带状牧草组合措施能较好地提高0．50～1．00mm水稳性团聚体的含量，但对土壤有机质和速效养分效果不明显。带状牧草和稻草覆盖组合措施能显著提高〉4．00mm水稳性大团聚体含量，但对土壤有机质和速效养分影响不明显。稻草覆盖提高0．25～4．00mm水稳性团聚体含量的效果好于稻草覆盖和带状牧草组合措施，而PAM和带状牧草组合措施对提高〉0．25mm水稳性团聚体含量的效果好于带状牧草，但对于0．25～1．00mm粒径效果不如PAM。

English. Erosion restoration measures such as,polyacrylamide （PAM）,straw mulching,zonal forage （paspalum notatum）,and the combination of them were used in the eroded plots of red soil rotated by peanut and wheat in southern area of Hubei Province. The water stable aggregates（more than 4. 00, 2.00-4. 00,1.00-2.00,0. 50-1.00,0. 25-0. 50 mm） and the content of available N,P and K in the eroded red soil was detected to reveal the effects of erosion restoration measures on aggregate stability and available nutrient. The results showed that straw mulching could significantly increase the contents of 1.00-2. 00 and 2. 00-4.00 mm water stable aggregate （WSA） ,and the increase rate was 40% for the contents of more than 0. 25 mm WSA. In the straw mulching treatment, the contents of organic matter and available K separately increased 20% and 150%after planting wheat. The measures of PAM and the combination of PAM and zonal forage could increase the content of 0. 50-1.00 mm WSA,and rates were 25% higher than that of the control, but they were not significant for the increase of the soil organic matter and available nutrients. The combination of zonal forage and straw mulching could significantly increase the content of more than 4. 00 mm WSA by 500% compared to the control,but no obvious influences to the soil organic matter and available nutrients. The measure of straw mulching was better than the combination of straw mulching and zonal forage for increasing the content of 0. 25-4. 00 mm WSA. In improving the content of more than 0. 25 mm WSA,the effect of the composition of PAM and zonal forage was better than the measure of zonal forage,but less than the measure of PAM for increasing the content of 0. 25-1.00 mm WSA.