再生水地下滴灌对玉米生育期土壤脲酶活性和硝态氮的影响

Effects of Subsurface Drip Irrigation on Soil Urease Activity and Nitrate During Maize Growing Season While Applying Treated Sewage Effluent

为了探讨再生水地下滴灌条件下土壤脲酶活性和硝态氮的关系,通过2a再生水地下滴灌试验,研究了滴灌带埋深和灌水量对玉米生育期0~50cm深度土壤脲酶活性和硝态氮分布的影响。灌水量设置灌溉需水量的70%、100%和130%3个水平,滴灌带埋深设置0、15和30cm 3个水平。结果表明,再生水地下滴灌提高了0~50cm脲酶活性。灌水量和滴灌带埋深均对土壤脲酶活性和硝态氮含量产生了显著影响,硝态氮随灌水量和滴灌带埋深的增大运移深度增加,0~10cm深度脲酶活性以70%灌溉需水量和埋深0cm较高,10~50cm深度脲酶活性以130%灌溉需水量和埋深30cm较高。相关分析表明,硝态氮含量和脲酶活性在玉米生育期内由极显著正相关向负相关转变。

In order to study the relationship between urease activity and nitrate in soil for subsurface drip irrigation system while ap- plying treated sewage effluent, field experiments were conducted during the growing seasons of maize in 2014 and 2015 to study the effects of irrigation level and lateral depth on the distribution of urease activity and nitrate in 0-50 cm soil depths. Three different irrigation levels of 70%, 100%, and 130% of crop evapotranspiration and three lateral depths （0, 15, and 30 era） were used. The results showed that subsurface drip irrigation with treated sewage effluent enhanced urease activities in 0-50 cm soil compared with the measurement prior to sowing. The urease activity and nitrate content were significantly affected by irrigation level and lateral depth. Both irrigation level of 130% and lateral depth at 30 cm produced higher urease activities in 10~50 em depths due to more ni- trate moving to 10-50 cm depths. Also higher urease activities were observed in 0-10 em depth with irrigation level of 70% and lateral depth at 0 cm. A correlation analysis between urease activities and nitrate content revealed a reduced degree of correlation during the growing seasons of maize.