添加碳氮对大豆秸秆还田土壤酶活性及微生物量碳的影响

Effects of Carbon and Nitrogen Addition on Soil Enzyme Activity and Microbial Biomass Carbon Content of Soybean Straw after Returning to Field

试验设置3因素(秸秆(S)、红糖(T)、氮素(N))、2水平(添加(1)、未添加(0)),共8个处理STN1、STN0、SN1、SN0、TN1、TN0、N1、N0,在室温下进行60d的土壤培养试验,测定各处理在培养时期内的土壤呼吸、微生物量碳、3种土壤酶(蔗糖酶、脲酶、过氧化氢酶)的变化特征。结果表明:各处理的土壤呼吸速率均表现为前期快速增加,达到峰值后逐渐下降随之趋于稳定;随培养时间变化,各处理土壤酶活性呈现先升高后降低的趋势,大豆秸秆还田与不还田处理相比,对3种酶(蔗糖酶、过氧化氢酶、脲酶)以及微生物量碳含量有促进作用,其中秸秆+氮肥对土壤脲酶活性的提高最显著,秸秆+红糖+氮肥处理对土壤呼吸速率、蔗糖酶活性、过氧化氢酶活性、微生物量碳含量的影响最显著。

Three factors (straw (S), brown sugar (T), nitrogen (N)) were set, and two levels (add (1), no (0)) were processed in total, which were STN1, STN0, SN1, SN0, TN1, TN0, N1, N0, a total of 60 days of soil culture test at room temperature, the soil respiration, microbial biomass carbon and three soil enzymes (sucrose, urease, and catalase) in each treatment period were measured. The respiration rate of each treatment showed a rapid increase in the early stage, and gradually decreased after reaching the peak value. The enzyme activity of each treatment showed a trend of increasing first and then decreasing with the change of culture time. Compared with non-returning treatment, soybean straw returning to the field has a promoting effect on three enzymes (sucrose, urease, and catalase) and microbial biomass carbon, and the treatment of straw+nitrogen fertilizer had the best effect on improving soil urease activity. The treatment of straw+brown sugar+nitrogen fertilizer had the most significant effects on soil respiration rate and the contents of invertase and catalase activity and microbial biomass carbon.