Effects of maize straw mulching frequency and amount on soil mesofauna in a no-tillage system
To understand the response of soil mesofauna to the straw mulching amount and frequency,this study was carried out at the Conservation Tillage Research and Development Base of the Chinese Academy of Sci-ences in Jilin Province.The study included five treatments:high frequency and low amount straw mulching(HF-1/3),high frequency and high amount straw mulching(HF-2/3),low frequency and low amount straw mulching(LF-1/3),low frequency and high amount straw mulching(LF-2/3),and conventional tillage with no straw mulching(CT)as the control.The results showed that straw mulching significantly increased the density of soil me-sofauna compared to CT.In spring,the total density of soil mesofauna in LF-2/3 was significantly higher than the other treatments,being 4.6 times higher than the CT,2.6 times higher than the HF-1/3,2.7 times higher than the HF-2/3,and 2.4 times higher than the LF-1/3,respectively.In summer,the total density of soil mesofauna in HF-1/3 was significantly higher than that in LF-1/3,being 3.8 times higher than the LF-1/3,while the HF-2/3 was 1.6 times higher than the LF-2/3 under the same amount of straw mulching.However,there was no significant difference between the different amount straw mulching treatments under the same straw mulching frequency.In au-tumn,the total density of soil mesofauna in HF-2/3 was significantly higher than the other treatments,being 8.2 times higher than the CT,2.5 times higher than the HF-1/2,2.3 times higher than the LF-1/3,and 3.4 times higher than the LF-2/3,respectively.The community diversity index was significantly higher in LF-1/3 than that in HF-2/3 in summer,and there were no significant differences among the treatments throughout the rest of the season.The community evenness index in HF-2/3 was significantly higher than that in LF-2/3 in spring;HF-2/3 was significantly lower than that in CT and LF-1/3 in summer.HF-2/3 was significantly lower than that in HF-1/3,LF-1/3 and LF-2/3 in autumn.Individual densities of the major soil mesofauna taxa groups generally were higher in high frequency treatments than low frequency treatments under the same amount of straw mulching in summer and autumn.The response of the density of Acari and their high proportion suborder of Oribatida to the mulching frequency and amount was consistent with the total density of mesofauna.The density of Collembola in LF-2/3 was significantly higher than CT and LF-1/3 in spring;HF-1/3 was significantly higher than CT in summer;and HF-2/3 was significantly higher than the other treatments in autumn.The density of Hypogastruridae in LF-2/3 was significantly higher than CT in spring;HF-1/3 was significantly higher than CT and LF-1/3 in summer;HF-2/3 was significantly higher than LF-2/3;and HF-1/3 was significantly higher than LF-1/3 in au-tumn.The density of Isotomidae in HF-2/3 was significantly higher than CT,HF-1/3,and LF-2/3.The density of Entomobryidae in the high frequency straw mulching treatments was higher than that in the low frequency straw mulching treatments.The density of Diptera larvae in spring was significantly higher in LF-2/3 than in CT;the HF-1/3 was the highest in both summer and autumn.For the density ratio of Acari to Collembola,the LF-2/3 treat-ment was much higher than HF-2/3 and much greater than 1 in spring,whereas it was in LF-2/3,HF-2/3,and HF-1/3 were significantly lower than LF-1/3 and CT in autumn.Overall,under the same amount of straw retur-ning,high-frequency straw returning is better for the survival of medium-sized soil animals than low-frequency straw returning.However,at a certain returning frequency,the amount of returning needs to be considered.
万方数据
维普
