Characteristics of straw decomposition time under different straw returning methods

Taking wheat, rapeseed, and rice straw from major crops in Xinyang City, Henan Province, as research subjects, decomposition bag method was used to investigate straw decomposition characteristics under different straw returning conditions．Results have found that under surface（0 cm）returning conditions, wheat straw exhibited higher decomposition rates in paddy fields where 50%, 70%, and 90% decomposition achieved in 57, 103, and 203 days, respectively, compared to 81, 145, and 282 days in dryland．For rapeseed straw, when decomposition reached 50%, 70%, and 90%, time required for underground（5 to 10 cm）returning was 91, 164, and 321 days, respectively, while for surface（0 cm）returning, time required was 114, 199, and 383 days．For rice straw decomposition at 50%, 70%, and 90%, time required for underground（5 to 10 cm）returning was 98, 175, and 342 days, respectively, while for surface incorporation（0 cm）, time required was 114, 197, and 378 days．Wheat straw has exhibited faster decomposition rate in paddy fields, and underground straw returning methods improved decomposition efficiency than surface steam returning．Both underground and surface straw returning were influenced by soil moisture and accumulated temperature．High soil moisture and temperature significantly increased bacterial abundance, leading to faster straw decomposition rates．