Microbial residues were increased by film mulching with manure amendment in a semiarid agroecosystem

ABSTRACT

Amino sugars, as a kind of microbial residue, are strongly associated with cycling of microbial-derived soil organic matter. However, responses of amino sugars to agricultural practices on the Loess Plateau in North-western China are poorly known. The objective was to evaluate effects of film mulching (no film mulching + NPK fertilizers, CK; film mulching + NPK fertilizers, PF; film mulching + NPK fertilizers + cow manure, FM) on accumulations of amino sugars in this region. FM significantly increased total amino sugar by 190.46 mg kg⁻¹ in 0–10 cm layer and 214.66 mg kg⁻¹ in 10–20 cm layer relative to CK, but PF significantly decreased it by 139.28 mg kg⁻¹ in 0–10 cm layer. Ratios of glucosamine to muramic acid were markedly decreased by 2.50 in 0–10 cm layer and 2.28 in 10–20 cm layer in FM than CK, suggesting a tendency of microbial residues pool shift towards bacterial residues in this agroecosystem. These results indicated film mulching alone was not benefitial to accumulation of amino sugar while organic manure contributed to the build-up of amino sugar partly due to manure contained microbial residues. The different patterns of amino sugars suggested significant changes in the quality of microbial-derived organic matter.

KEYWORDS:

• Agricultural practices
• amino sugars
• organic manure
• soil organic carbon
• fungal and bacterial residues

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (No. 41671307, 51279197); the National Key Research and Development Program (No. 2017YFD0201807); the Natural Science Basic Research Plan in Shaanxi Province of China (No. 2017JM3011, 2012JM3010) and the Special-Funds of Scientific Research Programs of State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau (No. A314021403-C4).