秸秆覆盖对黑土区土壤微生物量、酶活性及大豆产量的影响

Effects of Straw Mulching on Soil Microbial Biomass,Enzyme Activity,and Soybean Yield in Black Soil Areas

为了探究秸秆覆盖量对黑土区土壤微生物量、酶活性及大豆产量的影响,以垦丰16为试验材料,分别设置无秸秆覆盖(CK)、0.5 kg/m2秸秆还田覆盖(T1)、1.0 kg/m^(2)秸秆还田覆盖(T2)、1.5 kg/m^(2)秸秆还田覆盖(T3)4种处理,测定大豆生育期内耕作层土壤细菌、真菌、放线菌数量以及脲酶、过氧化氢酶活性和大豆产量,对比分析不同秸秆覆盖量对土壤微生物量、酶活性及大豆产量的影响。结果表明,大豆全生育期内土壤细菌数量呈先升高后降低的趋势,其中T2处理细菌总数量最大,分别较T1、T3、CK处理提高33.08%、9.30%、65.38%;真菌数量呈先升高后降低、再升高再降低的趋势,其中T2处理真菌总数量最大;放线菌数量整体上呈先升高后降低的趋势,随着秸秆覆盖量的增加而增加。各处理脲酶活性表现为T1>T2>T3>CK,且秸秆覆盖处理分别较CK处理提高32.64%、29.42%、18.23%;过氧化氢酶活性表现为T2>T3>T1>CK,不同处理酶活性均在开花期达到最高。秸秆覆盖处理大豆产量显著高于CK,秸秆覆盖量对大豆产量的影响并未随着秸秆覆盖量的增加而持续增加,T2处理产量最高。大豆产量与脲酶活性、细菌数量呈极显著正相关关系,与真菌数量呈显著正相关关系;过氧化氢酶活性与脲酶活性、真菌数量呈显著正相关关系。综上,1.0 kg/m2秸秆覆盖是黑土区最优秸秆覆盖量。

In order to investigate the effects of straw coverage on soil microbial biomass,enzyme activity,and soybean yield in black soil areas,Kenfeng 16 was used as the experimental material.Four treatments were set up,including no straw coverage(CK),0.5 kg/m^(2) straw return coverage(T1),1.0 kg/m^(2) straw return coverage(T2),and 1.5 kg/m^(2) straw return coverage(T3),to determine the number of bacteria,fungi,actinomycetes,and the activity of urease and catalase in the soil of the cultivation layer during the soybean growth period,and soybean yield,and compare and analyze the effects of different straw coverage amount on soil microbial biomass,enzyme activity,and soybean yield.The results showed that the number of soil bacteria showed a trend of first increasing and then decreasing throughout the entire growth period of soybean,with T2 treatment having the highest total number of bacteria,which increased by 33.08%,9.30%,and 65.38% compared to T1,T3,and CK treatments,respectively.The number of fungi showed a trend of first increasing,then decreasing,and then increasing and then decreasing,with T2 treatment having the highest total number of fungi.The overall number of actinomycetes showed a trend of first increasing and then decreasing,and increased with the increase of straw coverage.The urease activity of each treatment showed T1>T2>T3>CK,and the straw covering treatment increased by 32.64%,29.42%,and 18.23% compared to CK treatment,respectively.The activity of catalase showed T2>T3>T1>CK,and the enzyme activity reached the highest in different treatments during the flowering period.The soybean yield under straw cover treatment was significantly higher than that under CK.The impact of straw cover on soybean yield did not continue to increase with the increase of straw cover,with T2 treatment having the highest yield.There was a significant positive correlation between soybean yield and urease activity,bacterial count,and fungal count;There was a significant positive correlation between catalase activity and urease activity,as well as the number of fungi.In summary,under the conditions of this study,1.0 kg/m^(2) straw coverage is the optimal straw coverage amount.