芝麻、花生和田菁秸秆还田的化感效应研究

Allelopathic Effect of Returning Plant Residue to Field from Sesame,Peanut and Sesbania

采用盆栽模拟实验研究了具化感作用的芝麻(Sesamum indicum)、花生(Arachis hypogaea)和田菁(Sesbania cannabina)秸秆全株还田对萝卜(Raphanus sativus)、黑麦草(Lolium multiforum)和黄瓜(Cucumis sativus)生长及土壤养分状况的影响,旨在评价秸秆还田释放养分与化感作用对后茬作物幼苗生长效应的综合影响。结果表明:秸秆还田能改善土壤养分状况,对后茬作物幼苗生长具有较好的促进作用。3种作物秸秆还田促进幼苗生长的大小顺序为花生秸秆>田菁秸秆>芝麻秸秆>对照,其中芝麻秸秆对土壤速效磷、速效钾含量提高最大,而花生和田菁秸秆对土壤有机质、全氮的贡献值远远高于另两种处理。3种秸秆还田均对后茬作物幼苗生长和土壤养分具有促进作用,其释放的养分因子占主导作用,而化感作用并未明显表现出阻碍后茬作物幼苗生长。可能原因在于秸秆还田后导致较高pH和土壤养分利于植物生长,并影响了秸秆化感物质的活性和化感作用的发挥。

A pot experiment in greenhouse was conducted to study the effects of returning plant residue from sesame（Sesamum indicum）,peanu（tArachis hypogaea）and sesbania（Sesbania cannabina）on subsequent seedlings growth and soil nutrient.After soil was amended with different crop straws,the biomass of radish（R.sativus）,ryegrass（L.multiforum）and cucumber（C.sativus）increased significantly,and soil nutrients also increased significantly.The results showed that the order of the biomass of subsequent seedlings was peanut sesbania sesame CK.The improvement of soil available P and K was better by returning the plant residue of sesame than the other two crops.The improvement of soil total nitrogen was better by returning the plant residue from peanut and sesbania than by sesame.Comparing with negative effect of allelopathic effect caused by the phyto-toxic substances produced in the initial phase of the decomposition processes.The positive impact caused by the accumulation of nutrient overcame the negative impact caused by allelopathic chemicals.Higher soil pH caused by returning crop residue may also play an important role.