Litter quality regulates cover crop litter decay alongside altered microbial facets

Abstract

Cover crops litter decay is a vital component of nutrient cycling in agroecosystems; however, how litter quality affect decay process via microbial facets at different decay stage remains unclear. Here, we performed a 112-d decay experiment using the litter of two winter cover crop species (a legume and a grass) to clarify the relationship between the temporal dynamics of litter-inhabiting microbes and litter decay in agroecosystems. Legume litter decayed faster (k = 0.064 ± 0.002 days⁻¹) than grass litter (k = 0.053 ± 0.003 days⁻¹) during the early stage (0–28 D) of decay. Wood saprotrophs and bacteria, capable of performing lignin degradation, were generally more abundant in legume litter (0.003 % and 47.77 %, respectively) than in grass litter (0.002 % and 39.24 %, respectively) during the early stage of decay. Litter quality affected the decay process through its effects on microbial functional profiles and interactions; legume litter decay increased as the abundance of specific functional guilds increased and network complexity decreased. Overall, our findings indicated that litter quality affected litter decay process and relevant litter-inhabiting microbial facets is restricted to the early stage of decay.