Chin J Plant Ecol

   

Study on non-additive effect of mixed decomposition of maize and potato straw

Lingkang chen1,ping zhao1,ding wang1,向 蕊1,Guang-Qiang Long   

  • Received:2022-08-22 Revised:2022-10-26 Published:2022-11-02
  • Contact: Guang-Qiang Long

Abstract: Aims The mixed decomposition of organic residues is crucial to the material cycle of terrestrial ecosystems, but there is still a lack of research on the decomposition process of mixed straw in farmland ecosystems. Methods In this study, a 6-month maize straw, potato straw and maize-potato composited straw decomposition bag landfill experiment was set up in maize (Zea mays) monoculture, potato (Solanum tuberosum) monoculture and maize-potato intercropping plot experiments. The effects of straw type and decomposition environment on microbial carbon metabolic activity of straw were analyzed by Biolog-Eco microplate method. Important findings The results showed that the mixture of potato straw and maize straw had a synergistic effect on the decomposition process. The decomposition rate and microbial metabolic activity of composited straw were higher than those of straw alone, which increased the utilization of carbohydrate and carboxylic acid substrates by microorganisms. This synergistic effect is weakened over time. Random forest model and structural equation model analysis showed that soil dissolved organic carbon, nitrate nitrogen, ammonium nitrogen content and straw carbon nitrogen ratio (C:N) were important factors driving straw decomposition. In short, straw mixing promotes straw decomposition. This conclusion provides a scientific basis for farmland straw management.

Key words: composite straw, intercropping, microbial metabolic activity, decomposition of organic material, non-additive effects