覆盖和草篱对红壤坡耕地花生生长和土壤特性的影响

Effects of Straw Mulching and Vetiver Grass Hedgerows on Peanut Growth and Soil Property in Red Soil Sloping Field

开展了稻草覆盖和香根草篱控制红壤旱坡地水土流失的长期定位试验,研究了香根草篱、稻草覆盖、香根草篱＋稻草覆盖3种类型的水土保持耕作措施和常规耕作对红壤旱坡地土壤物理学、化学、生物学特性和花生生长、产量的影响。结果表明,香根草篱＋稻草覆盖和稻草覆盖措施实施5 a后仍能促进花生花荚期茎、叶、根、果生长发育,与常规耕作相比,花生增产明显,增产量为460.65-761.11 kg/hm^2,增产率为6.19%-20.32%;香根草篱措施虽然没有明显地促进花生生长和产量,但其减流减蚀效果显著,综合效益仍优于常规耕作。稻草覆盖和香根草篱及其组合措施建立5 a后,与常规耕作相比,3种类型的水土保持耕作措施土壤化学性状均有不同程度的提高,并以香根草篱＋稻草覆盖措施的提高效果最明显;香根草篱＋稻草覆盖措施下土壤小于2μm的微团聚体含量和土壤主要微生物类群总量明显高于常规耕作,改善了土壤物理结构,提高了土壤微生物活性。表明稻草覆盖和香根草篱等水土保持耕作措施是适合红壤旱坡地农业可持续发展的有效模式,其中香根草篱＋稻草覆盖组合模式在土壤质量改善和作物增产效果方面尤为突出。

The study is aimed to identify the law of how soil property and peanut growth respond to soil and water conservation（ SWC） tillage in order to provide a scientific basis for preventing soil erosion,improving soil fertility and increasing peanut yield in red soil sloping land. The impacts of three types of SWC tillage practices,namely vetiver grass hedgerows（ VH）,straw mulching（ SM） and vetiver grass hedgerows plus straw mulching（ VH ＋ SM）,on soil property and peanut yield were examined and compared with conventional tillage（ CT） through a long-term located experiment in sloping land of red soil. Results showed that after five years of the experiment,VH ＋ SM and SM treatments could still promote the growth of stem,leaf,root and fruit of its in peanut flowering and podding periods,and created significant peanut yield increments of 460. 65 kg / hm^2 and 761. 11 kg / hm^2 with increasing rates of6. 19% and 20. 32%,respectively,compared with CT. Although VH treatment had no obvious influence on promoting peanut growth and yield,its effect on reducing erosion was remarkable,and thus its comprehensive benefit were still better than that of CT. The three SWC tillage practices all improved the chemical properties of soil to some extent compared with CT. Among them,VH ＋ SM treatment exhibitedthe best performance,and increased the soil organic matter,total nitrogen and available phosphorus contents by 36. 81%,64. 03%,and 43. 50%,respectively. Under VH ＋ SM tillage practice,the soil microaggregate（ with diameter less than 2 μm） content and the total amount of main microbial population were significantly higher than those under CT,indicating that soil physical structure and microbial activity were improved. Hence,the SWC tillage practices were fit for sustainable agricultural development in arid sloping land of red soil in South China. Especially,the combination mode of vetiver grass hedgerows plus straw mulching had outstanding effect on improving soil quality and crop yield.