云南省设施栽培土壤脲酶活性变化趋势研究

Changes of Urease Activities under Greenhouse Soils in Yunnan Province

以云南设施栽培面积最大的六个片区设施土壤为研究对象,通过实地采样与分析测定,重点研究了设施土壤中和氮素转化有密切关系的脲酶活性的变化趋势。结果表明：大棚设施土壤中0～20cm脲酶活性变化范围为0.093-1.505（mg g^-1,24h.37℃）,平均值为0.474（mg g^-1,24 h.37℃）,略低于露地;20-40 cm脲酶活性变化范围为0.102-1.279（mg g^-1,24 h.37℃）,平均值为0.396（mg g^-1,24 h.37℃）,较露地菜园土高;上下两层土壤中脲酶活性都随着设施栽培年限的增加,均表现为增-降-增;相关分析表明,土壤pH值与脲酶活性呈极显著正相关,而与和碱解氮相关性不显著。

Choosing the largest one of the six facilities cultural area in Yunnan Province,the urease activities and physical-chemical properties were determined.The trend of urease activities was closely related to nitrogen transformation.The results showed that the soil urease activities in 0-20cm soil layer under greenhouse were 0.093-1.505（mg g,24h.37℃）,with the average of 0.474（mg g,24h.37℃）,lower than that in open soil.The soil urease activities in 20-40cm soil layer under greenhouse were 0.102-1.279（mg g,24h.37℃）,with the average of 0.396（mg g,24h.37℃）,higher than that in open soil.The urease activities in the two greenhouse soil layers had a ＂V＂-shaped change patterns with greenhouse life in fifteen years.Soil urease activities were significant positive correlation with soil pH.