From agronomic performance to behavioral adoption of biochar‑based slow‑release fertilizer in saline‑alkali rice: A single‑season field trial and survey‑based SEM analysis

Saline-alkali soil degradation severely hinders sustainable rice production, with conventional NPK fertilizers suffering from low nutrient use efficiency and aggravated soil secondary salinization in such fragile agroecosystems. This study integrated field agronomic trials and behavioral empirical analysis to explore starch-encapsulated zeolite-biochar-based compound fertilizer (SC-ZEO/BCF) for coastal saline-alkali rice systems in southeastern China, via an extended Motivation-Opportunity-Ability framework incorporating trust as a core mediating construct. Agronomic results showed SC-ZEO/BCF at 0.8 × (20% NPK reduction) notably boosted rice yield and elevated NUE by 82.79%, while enhancing soil desalination and alkalinity amelioration, and achieving the highest net profit with markedly estimated reductions in nitrogen‑related environmental costs from leaching and gas emissions. Structural equation modeling of 230 valid farmer surveys revealed motivation, ability and opportunity positively affected adoption willingness directly and/or indirectly via trust, with trust exerting the strongest direct effect ( β =0.433); the indirect effect of opportunity on adoption willingness via trust was positive and significant, representing the sole positive pathway. Ability emerged as the top predictor of trust ( β =0.492) among all the driving factors. This study suggests potential agronomic, economic and environmental advantages of SC‑ZEO/BCF under the tested conditions, and highlights trust as a pivotal driver for technology adoption, providing evidence-based insights for policymakers and extension services to promote green fertilization technologies in saline-alkali agricultural systems.