摘要
新疆棉区普遍实行秸秆还田,棉田土壤酶活性受到连作障碍的负面效应与长期秸秆还田培肥地力的正面效应的双重影响;通过定点微区实验,对比秸秆还田和未秸秆还田土壤酶活性的变化趋势,研究连作条件下秸秆还田与否对棉田土壤酶活性的影响。结果表明:实行秸秆还田后,土壤脲酶活性随着连作年限的延长先降后升,连作不超过10 a,土壤脲酶活性呈现下降趋势,超过10 a逐渐上升;实行秸秆还田后蔗糖酶活性在R5和R10处理较R1有较大幅度的下降,降幅分别为48.4%和44.8%,连作10 a后蔗糖酶活性增强,土壤状况趋于好转;过氧化氢酶活性随连作年限的延长先降低后升高,短期连作土壤过氧化氢酶活性较低,过氧化氢分解受阻,影响棉花的正常生长,连作年限超过10 a过氧化氢酶活性升高,解毒能力较强,加快分解过氧化氢,有利于减轻过氧化氢的毒害作用;过氧化物酶活性随着连作年限的延长持续上升,其中R5、R10、R15和R20过氧化物酶活性分别比R1增加了4.8%、7.9%、19%和29.6%。
By comparing the tendency of changing of soil enzyme activity between the cotton field with straw returning and without straw returning,study the effect of returning cotton stalk to the enzyme activity.The results show that： the Urease activity declines first and rises later along with the continuous cropping after returning cotton stalk to field.the Urease activity takes on the declining trend when continuous cropping less than 10 years,while rises more than 10 years.After straw returning,the enzyme activity reduces more largerly by 48.4% and 44.8% in R5 and R10 than in R1.With continuous invertase activity for 10 years,Sucrase activity is enhanced,and the condition of soil tends to get better.Catalase activity reduces first after the continuous cropping and rise later,the short-term impact of cropping makes the Catalase activity low,and obstructs the decomposition of hydrogen peroxide,affectes cotton＇s normal growth.when the continuous cropping surpasses 10 years,the Catalase activity increases,speeds up the decomposition of peroxide,and helps to lighten the toxicity of hydrogen peroxide.Peroxidase activity continues to increase with the extension of the impact of fixed number of years,.For example,peroxidase activity in R5,R10,R15 and R20 increases more respectively by 4.8%,7.9%,19% and 29.6% than in R1.
出处
《生态环境学报》
CSCD
北大核心
2011年第5期881-885,共5页
Ecology and Environmental Sciences
基金
"973"计划前期研究专项(2006CB708401)
国家科技重大专项课题(2009ZX07425-003)
关键词
棉花连作
秸秆还田
土壤酶活性
continuous cropping of cotton
returning stalk to the field
soil enzyme activity
