Study on soil biochemical activity characteristics in Weibei arid region | 渭北旱塬土壤生化活性特征研究

chinois. 筛选能够表征土壤肥力水平的酶类和参数。采用非缓冲液法，对采自渭北旱塬陕西长武县农田19个土样的10项生化指标（转化酶、纤维素酶、淀粉酶、蛋白酶、脲酶、磷酸酶、过氧化氢酶、脱氢酶、尿酸盐酶和土壤呼吸强度）进行测定；并采用相关和主成分分析法，对土壤酶活性、土壤呼吸强度之间及其与土壤化学性质间的相关性和主成分综合得分进行评判；最后采用土壤酶总体酶活性参数（TEI、TEI5）对19个供试土样的肥力进行评价，并分析了其与土壤化学性质的相关性。土壤转化酶、脲酶、脱氢酶、土壤呼吸强度对土壤环境条件的改变较为敏感；10项土壤生化指标中，仅转化酶、脲酶、磷酸酶、脱氢酶活性和土壤呼吸强度之间及其与大多数理化性质间呈显著或极显著相关，揭示此5项生化指标与土壤化学性质关系密切，且在一定程度上可指示土壤肥力水平的高低；构建的总体酶活性参数TEI和TEI5，与土壤酶活性、土壤呼吸强度及土壤化学性质主成分分析获得的土壤肥力综合得分均达极显著正相关。土壤总体酶活性参数TEI和TEI5可作为表征土壤肥力的重要指标，并能反映土壤整体酶活性和呼吸强度的高低。

anglais. The study was to detect the enzyme types and enzyme index indicating soil fertility level. This experiment investigated ten soil biochemical properties (invertase, cellulase, amylase, proteinase, urease, phosphatase, catalase, dehydrogenase, uricase and respiration intensity) in Weibei arid area by using no-buffer method. The data was processed with the methods of correlation analysis, principle component. Finally, the total enzyme index (TEI, TEI5) were used to estimate soil fertility of 19 soil samples, and the relationship between them and soil chemical properties were analyzed by correlation analysis. The results showed that soil invertase, urease, phosphatase, dehydrogenase and respiration intensity were more sensitive to environmental change among these ten biochemical properties. There was a significant correlation between invertase, urease, phosphatase, dehydrogenase and respiration, and also between these five soil biochemical properties and most of soil chemical properties. This indicated that these five soil biochemical properties can be used as indicators for soil fertility. Among total enzyme activity parameters TEI and TEI5 obtained in this experiment, TEI and TEI5 had a significant positive correlation with chemical properties with TEI5 as the most significant. By processing the data of soil enzyme activities, respiration intensity and chemical properties in principal component analysis, the soil information system obtained in this experiment can better show the variation of soil fertility and the multiple scores were significantly positively correlated with TEI and TEI5. This indicated that TEI and TEI5 can be used to monitor soil fertility levels and total enzyme activity and respiration intensity.