Supplementary file 1_Organic-inorganic fertilization regulates carbon sequestration-emission coupling through soil carbon fractions and bacterial community structure in dryland maize fields.docx

This study evaluated whether organic-inorganic fertilization could coordinate soil carbon accumulation, respiratory carbon losses, crop productivity, and bacterial community structure in a semiarid dryland maize system.</p>Methods<p>Using a long-term fixed-site field experiment established in 2012, we compared five fertilization regimes during 2024 and 2025: no fertilization (NA), chemical fertilizer alone (CF), combined organic and chemical fertilization (SC), organic fertilizer alone (SM), and maize straw alone (MS).

We measured maize productivity, soil total carbon and nitrogen, soil organic carbon and labile carbon fractions, soil CO₂ emissions, and bacterial community composition.</p>Results<p>Fertilization increased grain yield and soil carbon and nitrogen pools, although its effects on the growing-season carbon budget differed among treatments. SC produced the highest grain yield, improved carbon emission efficiency, and maintained positive growing-season net ecosystem productivity within the accounting framework used in this study.