保护性耕作对蚕豆根际土壤微生物数量和酶活性的影响

Effects of conservation tillage on soil microbes and enzyme activity in rhizosphere of broad bean

为明确保护性耕作对蚕豆根际土壤酶活性、微生物的影响,本研究采用传统耕作(Traditional tillage,T)、垄作(Ridge tillage,R)、传统耕作+半量秸秆覆盖(Traditional tillage+Half amount of straw mulching,TS_1)、垄作+半量秸秆覆盖(Ridge tillage+Half amount of straw mulching,RS_1)、传统耕作+全量秸秆覆盖(Traditional tillage+Whole amount of straw mulching,TS_2)、垄作+全量秸秆覆盖(Ridge tillage+Whole amount of straw mulching,RS_2)6个不同处理,研究保护性耕作对蚕豆土壤微生物(细菌、真菌、放线菌)、酶活性(多酚氧化酶、转化酶、酸性磷酸酶)的影响以及它们之间的相关关系,从而为蚕豆生产实践中选择合理的耕作方式奠定科学基础。试验表明:(1)以T为对照,RS_2、TS_2、RS_1、TS_1、R均能在不同程度上提高细菌、真菌、放线菌的数量,其中RS_2效果最为明显。RS_2处理下根际土壤细菌在苗期、分枝期、开花期、结荚期、成熟期较T处理分别提高525.00%、132.55%、294.44%、23.85%、175.00%,真菌较T处理分别提高27.00%、69.39%、156.41%、48.09%、79.55%,放线菌较T处理分别提高138.01%、178.26%、134.29%、100.23%、130.36%;(2)垄作和秸秆覆盖均能提高土壤各种酶的活性,其中RS_2效果最显著。RS_2处理下根际土壤多酚氧化酶在苗期、分枝期、开花期、结荚期、成熟期较T处理分别提高38.34%、43.24%、1.44%、48.96%、123.89%,转化酶较T处理分别提高79.13%、99.66%、50.95%、24.06%、63.00%,酸性磷酸酶较T处理分别提高26.32%、22.65%、25.32%、21.81%、22.38%。(3)土壤微生物数量与土壤酶均呈正相关,其中细菌、放线菌与酸性磷酸酶、转化酶、多酚氧化酶均呈极显著正相关,真菌与酸性磷酸酶、转化酶呈极显著正相关。

To clarify the effect of conservation tillage on soil microbes and enzyme activities in the rhizosphere soil of broad bean,the experiment was conducted with six treatments including traditional tillage（ T）,ridge tillage（ R）,traditional tillage ＋ half amount of straw mulching（ TS_1）,ridge tillage ＋ half amount of straw mulching（ RS_1）,traditional tillage ＋ whole amount of straw mulching（ TS_2）,and ridge tillage ＋ whole amount of straw mulching（ RS_2）.The effects of conservation tillage on soil microbes（ bacteria,fungi and actinomycetes）,enzyme（ polyphenol oxidase,invertase and acid phosphatase） activities in rhizosphere,the yield of broad bean,and the correlation between them were studied,so as to provide the reasonable farming methods for production practice of broad bean. The main results showed that：（ 1） Compared with T,the treatments of RS_2,TS_2,RS_1,TS_1,and R all can increase the amount of bacteria,fungi and actinomycetes in rhizosphere soil of broad bean,of which RS_2 has the most obvious effect. Under the RS_2 treatment,bacteria in rhizosphere soil compared with T increased by525.00%,132.55%,294.44%,23.85%,175.00% at the seedling,branch,blossom,pod and mature stage respectively,fungi in rhizosphere soil compared with T increased by 27.00%,69.39%,156.41%,48.09%,79.55%respectively,actinomycetes in rhizosphere soil compared with T increased by 138. 01%,178. 26%,134. 29%,100.23%,130.36% respectively;（ 2） The ridge tillage and straw mulching increased the soil enzyme activity,and the RS_2 treatment effect is the most significant Under the RS_2 treatment,the content of polyphenol oxidase in rhizosphere soil compared with T increased by 38.34%,43.24%,1.44%,48.96%,123.89% at the seedling,branch,blossom,pod and mature stage respectively,invertase in rhizosphere soil compared with T increased by 79.13%,99.66%,50.95%,24.06%,63.00% respectively,acid phosphatase in rhizosphere soil compared with T increased by 26.32%,22.65%,25.32%,21.81%,22.38% respectively;（ 3） There was a positive correlation between the amount of soil microorganisms and soil enzymes,among which bacteria and actinomycetes were significantly positively correlated with acid phosphatase,invertase and polyphenol oxidase,and fungi and acid phosphatase and invertase were significantly positive related.