Earthworms can enhance plant productivity and may also enhance the risk of net global warming potential in an agroecosystems. However, direct evidence demonstrating the value of field experiment for tackling questions about plant-soil-gas carbon by earthworm linkages over temporal and spatial scales in the field is scarce, particularly in intensively managed systems. In addition, the interaction of earthworm feeding strategies and organic amendment may profoundly modulate carbon (C) cycling. We examined these impacts using two earthworm species with distinct ecological strategies (epigeic Eisenia foetida and endogeic Metaphire guillemi) in combination with two manure application methods (surface mulch and incorporation into the soil) in a field experiment.
Results/Conclusions
Our results demonstrated that earthworm addition significantly increased the crop net primary and net global warming potential. However, earthworms addition significantly decreased the net ecosystem carbon budget by 9.5-16.0%. Through the multivariate redundancy analysis, earthworm-induced net ecosystem carbon budget were primarily attributed to soil microbial biomass C, dissolved organic C and mean weight diameter. Irrespective of earthworm species and manure application methods, earthworms had no stimulatory effects on the net greenhouse gas intensity and carbon efficiency ratio because the promotion of crop net primary and net global warming potential. In conclusion, understanding the earthworm ecosystem services will contribute to the development of environmentally improved management practice by allowing the full utilization of biological resources.