连作棉田土壤酶活性特征及其与土壤养分相关性研究

采用田间采样及室内测试的方法，研究了新疆棉区不同连作年限棉田的4种主要土壤酶活性特征及其与土壤肥力的关系。结果表明，棉田连作对过氧化氢酶的影响不明显，与荒地比较，脲酶和碱性磷酸酶在耕作后均有所增加，到5～7a普遍达到最大值，之后有所下降；蔗糖酶则3～5a达到最大，之后有所下降；土壤过氧化氢酶与pH值、土壤有机质、全氮、全磷、速效氮和速效磷含量呈正相关关系；脲酶与全氮呈显著相关r=0．92（P〈0．05），与碱解氮呈极显著相关r=0．99（P〈0．01）；碱性磷酸酶活性与全氮、全磷、速效氮和速效磷含量呈显著相关，相关系数分别为0．96（P〈0．01），0．89（P〈0．05），0．86（P〈0．05），0．89（P〈0．05），与pH值、速效钾则呈负相关关系；蔗糖酶活性与全氮和速效氮均呈显著和极显著正相关，与pH值和速效钾呈负相关。

Study on Correlation between Soil Enzymatic Activity and Soil Fertility in Continuous Cropping Cotton Field

A study on relationship between four soil enzymatic activities and soil fertility of the different reclaimed cotton land in Xinjiang was conducted by use of sampling in field and measuring in laboratory. The results showed that the activity of catalase was not remarkably affected by continuous cropping in cotton field; Activities of urease, alkalescence phosphatases and invertase reached maximum value for 5- 7 years,then decreased;Activity of invertase reached maximum value for 3--5 years,then decreased; Ac- tivities of catalase has positive correlation with pH value, soil organic matter, total N, total P, available N and available P;Activities of urease showed remarkably positive relationships with total N, r = 0.92（P〈 0.05） ,and showed extremely significant level with available N, r = 0.99（P 〈0.01）. Phosphatase showed remarkably positive relationships with the organic matter,total N,total P,available N,available P,and the correlation coefficient was 0.96（P 〈 0. 01） ,0. 89（P 〈0. 05） ,0. 86（P 〈 0.05）,0.89（P〈 0.05） respectively,and pH vatue was negatively correlated with available K;Activities of invertase had significant and extreme positive correlation with total N and available N. The available K had negative correlation with pH value.