秸秆还田对棉田土壤微生物和土壤呼吸速率的影响

通过基质诱导呼吸法和CO2释放量法研究了棉花秸秆还田对棉田土壤微生物生物量碳、土壤微生物活性和土壤呼吸速率的影响。结果表明,棉花秸秆还田提高了土壤微生物生物量碳含量,不同年份和土层土壤微生物生物量碳含量的变化趋势有所不同,两年试验结果0~20 cm土层除2012年8月和9月份外其它时期和20~40 cm土层除2013年8月份外其余时期土壤微生物生物量碳的含量均是秸秆还田显著高于秸秆未还田,而40~60 cm土层差异均未达显著水平。土壤微生物活性在不同年份和不同土层,除20~40 cm2013年4月和9月份以及40~60 cm土层的2013年5月和8月份差异未达显著水平外,其它时期秸秆还田均显著高于未还田处理。秸秆还田提高了土壤呼吸速率,不同年份和不同土层,除20~40 cm的2012年9月份和2013年6月份以及40~60 cm土层的2012年6月份、2013年5月份差异未达显著水平外,其它时期秸秆还田均显著高于未还田处理。

Effects of Straw Returning on Soil Microorganism and Soil Respiration Rate in Cotton Field

The effects of cotton straw returning on soil microbial biomass C, soil microbial activity and soil respiration rate were studied with substrate induced respiration and CO2 emission amount methods. The results showed that the cotton straw returning improved the content of soil microbial biomass C. The content of soil microbial biomass C of different years and different soil layers had different variation trends. In two - year experimental results, the microbial biomass C content of cotton straw returning were significantly higher than those of control in 0 -20 cm soil layer except for August and September in 2012 and 20 -40 cm soil layer except for August in 2013, while there was no significant difference between cotton straw returning and control in 40 ~ 60 cm soil layer. The soil microbial activity of cotton straw returning were significantly higher than those of control except for April and September in 2013 in 20 - 40 cm soil layer and May and August in 2013 in 40 ~ 60 cm soil layer. The cotton straw returning also improved the soil respiration rate. The soil respiration rate of cotton straw returning were significantly higher than those of control except for September in 2012 and June in 2013 in 20 ~40 cm soil layer and June in 2012 and May in 2013 in 40 ~60 cm soil layer.