地表太阳辐射减弱下麦田土壤酶活性及有效养分的动态变化

Dynamic changes in soil enzyme activity and active nutrient in winter wheat field with reduced surface solar radiation

采用田间遮光试验模拟不同程度太阳辐射减弱,在大田中设置85%、80%、60%、40%、0%的遮光梯度种植冬小麦,观测了冬小麦生长发育进程的变化,对冬小麦不同生育期土壤过氧化氢酶、转化酶、脲酶的活性和土壤速效磷、钾、铁、锰进行了研究。结果显示,不同程度的遮光都延迟了冬小麦的生育进程,太阳辐射减弱程度越大,物候延迟越显著。遮光60%、80%的处理促进了小麦近根区和远根区过氧化氢酶的活性。各遮光处理均降低了土壤脲酶活性和生育后期土壤转化酶活性,遮光80%时最为显著地降低了土壤转化酶活性。太阳辐射减弱降低了近根区土壤速效钾、铁、锰含量,随着遮光程度的增加呈CK>40%>60%>80%的趋势。

Field shading experiment was used to simulate reduced solar radiation at different percentages of 85% ,80% ,60% ,40% ,0% in winter wheat field. The activities of soil catalase, invertase, urease and the amount of available P, K, Fe, Mn were examined during different growth stages of winter wheat. Re-suits show that different shading percentages delayed the winter wheat growing process to different de-grees. The more the radiation decreased, the more significant the phonological delay was. The decrease of radiation at 60% and 80% promoted the activity of catalase near and away from the root zone of winter wheat. Reduced radiation significantly decreased soil urease and invertase activity in the late growth stages of winter wheat. The most significant invertase activity reduction occurred when the solar radiation was reduced by 80%. The reduced solar radiations decreased the urease activity in soil. The less radiation near the root zone decreased the amount of K, Fe, Mn, with a trend as follows ： CK 〉 40% 〉60% 〉80%.