松嫩草地土壤酶活性对土壤盐分季节动态的响应

以松嫩平原自然盐碱草地为对象,研究土壤酶活性与土壤盐分随生长季变化而变化的规律及相互关系,以初步探讨土壤酶活性对盐分离子变化的响应。结果表明:土壤过氧化氢酶、多酚氧化酶、过氧化物酶、蛋白酶、碱性磷酸酶和转化酶活性的季节变化规律不同,表现出一定的顺序作用。土壤总体酶活性指数在5月到9月先降低后升高,在6月最低,主要受转化酶活性变化的影响;土壤全盐含量从5月到9月逐渐降低,以6月、8月降幅最大,与5月相比分别降低28.04%、39.33%,主要受Mg^2+、HCO3^-含量降低影响。在整个生长季内,土壤酶活性与各盐分离子含量的相关性较好,随季节变化两者的相关性逐渐增强,在8月、9月相关性最强。不同季节不同土壤酶与不同盐分离子间的量化关系较好,而土壤总体酶活性指数与盐分离子间的量化关系较差。以上结果表明,不同土壤酶活性在不同季节随土壤盐分离子的变化而变化,可以尝试选用单一土壤酶活性指示不同季节单一盐分离子的变化,而土壤总体酶活性指数不能指示土壤盐分离子的变化。

Responses of Seasonal Dynamic of Soil Enzyme Activity to Soil Salinity in Songnen Saline-Alkali Grassland

In order to investigate soil enzyme activities in response to saline ion changes in Songnen saline-alkali grassland,the variation of soil enzyme activity and soil salinity with the growing season as well as the relationship between them were explored in the present study.The results showed that activities of soil catalase,polyphenol oxidase,peroxidase,protease,alkaline phosphatase and invertase were different,which revealed a certain order with seasonal changes.The total enzyme activity index of soil decreased at first and then increased from spring(May)to autumn(September).The lowest index was in summer(June),which was mainly affected duo to the change of invertase activity.The total salt content of soil decreased gradually from summer(May)to autumn(September)that the largest reduction was shown in summer(June)and autumn(August)duo to the lower Mg^2+ and HCO3^- contents,which was decreased by 28.04% and 39.33%,respectively,compared with spring(May).During the whole growing season,there was a close correlation between soil enzyme activities and the content of salt ions that the correlation gradually increased with seasonal changes,which was the strongest in autumn(August,September).A close quantitative correlation was observed between soil enzymes and salt ions in different seasons,while the quantitative correlation between soil total enzyme activity index and salt ions was poor.Above results indicated that enzyme activities of different types of soil varied with the change of soil saline ion in different seasons.Thus,it is possible to use a single soil enzyme activity to indicate the change of single saline ion in different seasons.However,the total enzyme activity index of soil could not indicate the change of soil saline ions.