【摘要】 选取5年棚龄温室土壤样品进行培养试验,研究温度(T)、水分(W)、施氮量(N)及其耦合效应对温室土壤pH及电导率(EC)的影响.结果表明:随着培养时间延长,温室土壤pH逐渐下降,下降速率可用一级反应模型进行定量描述,其速率常数受各因素的影响表现为N>W>W×N>T×W.EC在培养的第1周内快速上升到最大值后略有下降,并在培养后期逐渐趋于稳态值(ECsty),ECsty受N、W、T×W、T及W×N的影响,其中N、W、T×W和T的影响达到极显著水平,W×N的影响达到显著水平;通过减小施氮量及适当亏水灌溉可有效延缓温室土壤酸化和EC升高.建立了pH下降速率常数及ECsty回归模型,可对不同环境及水肥条件下土壤酸化及EC变化进行预测.更多还原

【Abstract】 A laboratory incubation experiment was conducted to study the effects of temperature(T),moisture(W),nitrogen application(N),and their combinations on the pH and EC of greenhouse soil having cultivated for 5 years.The results showed that with the increase of incubation time,soil pH was decreasing,which could be well described by the first-order kinetic model,and the pH decreasing rate(k) under effects of test factors was in the order of N>W> W×N > T×W.Soil EC increased quickly to the maxima in the first week of incubation,decreased slightly then,and finally reached to a constant(ECsty).The ECsty value was significantly affected by N,W,T×W,T,and W×N.Reducing nitrogen application and rational deficit irrigation could effectively postpone the soil acidification and EC increase.A regression equation of k and ECsty was established,which could be used to predict the changes of soil pH and EC under different conditions of moisture regime and nitrogen application.更多还原