Ecological stoichiometric characteristics of the straw-soil-microbial system in the straw checkerboard barriers across different laying years

This study utilized ecological stoichiometry to analyze the changes in the carbon (C), nitrogen (N), and phosphorus (P) within the straw-soil-microbial system across different laying years of straw checkerboard barriers in an arid sandy area, providing a reference for understanding the cycling process and regulation mechanism of these nutrients in such an environment. We selected straw checkerboard barrier areas laid for 1, 2, 5, 10, and 24 years as research plots with bare sandy land as the control. We collected soil samples at 0–20 cm and 20–30 cm depths along with straw samples of different degradation levels to investigate the changes in C, N, and P contents in the straw-soil-microbial system. The results showed that as the laying years of straw checkerboard barriers increased, straw N content, straw C:P and N:P ratios increased, while straw C content, straw C:N ratio decreased. Meanwhile, straw P content initially increased and then declined. The laying years of straw checkerboard barriers significantly impacted the contents of C, N, and P and the stoichiometry of straw. The contents of C, N, and P in soil and soil microbial biomass (MB) at different depths showed different responses, and their stoichiometry also varied based on the laying years of straw checkerboard barriers. Straw C and N contents showed a direct and significant positive impact on soil C-N-P stoichiometry, while straw N content displayed a direct and significant negative influence on C-N-P stoichiometry of soil MB. The primary factors influencing the changes in C, N, and P contents of the straw were soil total carbon (TC) content, MBN:MBP, and C:P ratios. The regulation of C-N-P cycling by the laying years of straw checkerboard barriers is a complex system involving “multiple components, multiple processes, and multiple scales”. Further research in this area should focus on mechanism analysis and scenario expansion.