Abstract
Residue mulching has been adopted to improve soil organic carbon and to prevent soil erosion and degradation, which in turn promote the sustainable development of soil ecosystems. Nematode metabolic footprints provide information about the responses of nematodes to resources and also help in quantifying the contributions of nematodes to ecosystem functions and services. However, how production and respiration components of nematode metabolic footprints vary in different mulching amounts is less clear. Therefore, to explore the impact of different mulching amounts on the production and respiration of nematode trophic groups, soil samples were collected from four mulching treatments (without mulching, with 33%, 67%, and 100% mulching of the stover remaining at harvest) at the depths of 0-5 cm and 5-10 cm in a 12-year long no-tillage system. Our results proved that the mulching effect on the production and respiration of fungivores was significant, and the production was 71.8%, 62.7%, 71.5% higher and respiration was 67.7%, 61.9%, 70% higher in 100% mulching treatment than without mulching, 33% and 67% mulching, respectively. More basal C flowed into the fungal decomposition pathways and fungivores contributed more to soil carbon sequestration through the decomposition of recalcitrant nutrients from residue at the end of crop growth. There was higher production than respiration in bacterivores and an opposite trend was observed in fungivores. Residue mulching increased the metabolic footprints of nematode communities and carbon use efficiency of fungivores and omnivores and predators and then enhanced the potential of soil carbon sequestration through the metabolic process of different nematode trophic groups.