Linkage between soil organic carbon and the utilization of soil microbial carbon under plastic film mulching in a semi-arid agroecosystem in China

ABSTRACT

Studying changes in soil organic carbon (SOC) pools and soil microbial C substrate utilization under plastic mulching in different seasons is of great significance for improving soil fertility and sustainable agricultural development. Based on a 2-year plastic film mulching experiment in northeastern China, we investigated the SOC, labile SOC fractions under three treatments: non-mulching (NM), autumn mulching (AM) and spring mulching (SM). The results showed that SOC decreased with soil depth under the AM and SM treatments compared with the NM treatment. The microbial biomass carbon (MBC) and dissolved organic carbon (DOC) under the AM treatment increased significantly in the 0–10 cm soil layer, by 31.2% and 27.2% (p < 0.05), respectively. The AM treatment significantly increased the utilization of amino acids and carbohydrate C sources. Redundancy analysis (RDA) indicated that MBC was the main factor influencing microbial metabolic functional diversity and accounted for the largest variation in the 0–10 cm layer. Pearson’s correlation analysis illustrated that MBC was strongly correlated with the utilization of the microbial C substrate. We suggest that AM may be an effective and sustainable management practice for improving soil quality and maintaining microbial functional diversity in semi-arid agroecosystems in this area.

KEYWORDS:

• Mulching treatments
• soil organic carbon fractions
• maize succession cropping system
• microbial functional diversity

Acknowledgments

This work was supported by the Public Welfare Industry (agriculture) research program (201503120), the National Natural Science Foundation of China (Grant Nos. 31470556, 31871575, 41601328), a special fund for basic scientific research operations of IEDA, CAAS, and the Bio-Water Saving and Dry Farming Innovation Team Project of CAAS.

Disclosure statement

No potential conflict of interest was reported by the authors.

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Additional information

Funding

This work was supported by the National Natural Science Foundation of China [31470556, 31871575, 41601328]; a special fund for basic scientific research operations of IEDA, CAAS; The Bio-Water Saving and Dry Farming Innovation Team Project of CAAS; Public welfare industry (agriculture) research program [201503120].