不同生态型蚯蚓对茶园土壤结构及土壤碳库的影响OA

Field experiment was conducted to explore the effects of inoculation of earthworms of different ecological types on soil aggregates,pore distribution and organic carbon pools in organic tea plantations.Four treatments were set up,including:Eisenia fetida inoculation(300·m-2)(E),Metaphire guillelmi inoculation(100·m-2)(P),Simultaneous inoculation of Eisenia fetida(150·m-2)and Metaphire guillelmi(50·m-2)(EP);control treatment(CK).The results showed that earthworms of different ecological types had greater influence on the distribution rather than the stability of soil aggregates.P treatment significantly increased the proportion of>5 mm aggregates.While E treatment reduced the proportion of>5 mm large water-stable aggregates and increased the proportion of 0.25 m≤d≤0.5 mm small water-stable aggregates significantly.The mixed inoculation of both earthworm species took the advantages of the two ecological types,so that the water-stable aggregates were mainly distributed between 1-0.25 mm.MWD(mean weight diameter)and GWD(geometric mean diameter)values of all the earthworm inoculation treatments increased significantly compared with CK.The MWD and GWD values of E treatment were the highest,which was significantly higher than that of other earthworm treatments.However,there was no significant difference in MWD and GWD values between EP treatment and P treatment.The results of pore size distribution showed that PAD(Percentage of aggregate disruption)had the most significant increase in inter-aggregates pores,and E increased the proportion of intra-aggregate pores(pores between particles)mostly.While EP increased both sectors,and the volume of capillary pores formed between clay particles and mineral layers decreased 6.1%-6.9%.This trend was completely consistent with the trend of soil water stability aggregates after earthworm inoculation.The inoculation of earthworms could significantly improve intensity of soil respiration,and increase soil microbial entropy and the total amount of soil active organic carbon pool.Among the earthworm treatments,that of E and EP improved the most.Compared with P treatment,E treatment had a stronger effect on soil active organic carbon.EP treatment had the largest increase in DOC(dissolved organic carbon)and TOC(total organic carbon),but at the same time,soil respiration also increased the most.In conclusion,E is mainly beneficial to increasing the content of small aggregates,the ratio of pores between aggregates and the content of soil DOC,while P is mainly conducive to the polymerization of large aggregates,and increase of large pores.EP treatment can better integrate the advantages of the two ecological types earthworms,and the symbiosis effect is good,which it plays a good role in soil structure improvement and carbon pool redistribution in organic tea plantations.