棉花秸秆还田对土壤微生物数量及酶活性的影响

为研究棉花秸秆还田对土壤微生物数量及酶活性的影响,于山东农业大学棉花科研基地德州市抬头寺经济开发区试验田进行试验,设棉花秸秆还田与未还田2个处理,研究连续4年棉花秸秆还田对0~60 cm土层土壤微生物数量及酶活性的影响。结果表明:棉花秸秆还田能够显著增加0~20 cm,20~40 cm,40~60 cm土层周年土壤微生物平均总数量,分别比未还田增加了19.87%,20.07%,56.15%;其中周年土壤细菌和真菌平均数量分别比未还田增加了20.91%、26.38%(0~20),20.59%、31.18%(20~40)和56.85%、32.30%(40~60),均达显著差异水平;周年土壤放线菌平均数量分别比未还田增加了4.29%,11.62%,54.00%,其中在20~40 cm和40~60 cm土层提高效果显著。棉花秸秆还田有利于提高土壤脲酶活性,0~20 cm,20~40 cm,40~60 cm土层土壤脲酶活性分别比未还田提高4.27%,13.43%和24.03%,其中对20~40 cm全部取样时期(9月除外)和除7月外40~60 cm土层其他取样时期的提高效果达显著差异水平;秸秆还田使土壤蔗糖酶活性在0~20 cm全部取样时期,除5月外20~40 cm土层其他取样时期,除8月外40~60 cm土层其他取样时期均得到了显著提高,分别比未还田提高了27.08%,46.96%,57.59%;除7,8月外,0~20 cm土层其他取样时期土壤过氧化氢酶活性在棉花秸秆还田条件下得到了显著提高,比未还田提高了8.73%,但除5,6月20~40 cm土层外,秸秆还田对20~40 cm和40~60 cm土层土壤过氧化氢酶活性的提高效果未达显著差异水平。以上结果说明持续棉花秸秆还田有利于保持和改善土壤的生物学特性。

Effects of Cotton Straw Returning Soil on Soil Microbes Quantites and Enzyme Activities

To study the effects of cotton straw returning soil on soil microbes quantities and enzyme activities,experiments were conducted at the Experimental Station of Shandong Agricultural University with two treatments (4-year straw returning soil and no straw returning soil) to investigate soil microbes quantities and enzyme activities across 0-60 cm depths after cotton straw returning for four consecutive years.The main results indicated that cotton straw returning soil significantly increased the quantity of total microbe by on average 19.87％ (0-20 cm),20.07％ (20-40 cm) and 56.15％ (40-60 cm),including soil bacteria and fungi quantity significantly increased by on average 20.91％,26.38％ (0-20 cm),20.59％,31.18％ (20-40 cm),56.85％,32.30％ (40-60 cm),respectively,comparing to no straw returning soil treatment;soil actinomyces quantity increased by on average 4.29％ (P ＞0.05),11.62％ (P ＜ 0.05),54.00％ (P ＜0.05) across 0-20 cm,20-40 cm,40-60 cm depths,respectively,comparing to no straw returning soil treatment.Cotton straw returning soil had no significant effect on soil urease activities at 0-20 cm depth,comparing to no straw returning soil treatment,while straw returning soil significantly increased soil urease activities across all sampling times except September at 20-40 cm and all sampling times except July at 40-60 cm depths by on average 13.43 ％ and 24.03 ％,respectively.Except May at 20-40 cm and August at 40-60 cm depths,soil sucrase activities after cotton straw returning soil significantly increased across 0-20 cm,20-40 cm and 40-60 cm depths by on average 27.08％,46.96％ and 57.59％,comparing to no straw returning soil treatment.Except July and August at 0-20 cm depth,cotton straw returning soil significantly increased soil catalase activity at by on average 8.73％,comparing to no straw returning soil treatment,while straw returning soil had no significant effect on soil catalase activity across 20-40 cm and 40-60 cm depths except May and June at 20-40 cm depths.These results indicated that cotton straw returning soil could maintain and improved the biological characteristics of the soil.