Effects of wheat straw addition on organic carbon mineralization in different types of soils
In order to explore the effects of wheat straw addition on the mineralization of organic carbon in different types of soils under the same culture conditions,this study used the indoor culture method to add wheat straw to black soil,windy sandy soil,purple soil,and yellow-brown soil.We aimed to investigate the dynamic changes in soil organic carbon mineralization and to elucidate the differences in the mechanism of the response to exogenous carbon addition in different types of soil organic carbon mineralization.The results showed that the soil organic carbon mineralization rates in all four soil types with straw addition increased significantly in the first 21 days and then stabilized compared with those observed without straw addition.In the first 7 days of incubation,the cumulative soil CO2 emissions increased rapidly by 2.41～3.87 times and then increased steadily and continuously.At the end of the incubation period,no significant difference was noted in the cumulative CO2 emissions of the four types of soils without straw.The cumulative CO2 emissions of all soils in the straw treatment were significantly increased by 2.52～3.41 times compared with those of the soils without straw.The cumulative CO2 emissions of the purple soil was significantly lower than that of the other three types of soil at 2 760.74 mg·kg-1 and that of the black soil was significantly higher at 4 168.99 mg·kg-1.Correlation analysis showed that total nitrogen dominated the mineralization rate of soil organic carbon with or without straw addition,and the two exhibited a significant negative correlation.Regardless of whether straw was added or not,the cumulative emission of soil CO2 was mainly influenced by soil pH and was significantly negatively correlated with pH.The cumulative emission of CO2 in response to the straw-added treatments was also positively affected by soil C/N simultaneously.When the same kind of straw is added to different types of soils,the response of soil organic carbon mineralization will vary,reflecting the inherent differences in the soils.Therefore,it is necessary to formulate reasonable straw return measures according to different soil properties.
万方数据
维普
