Long-term non-flooded cultivation with straw return maintains rice yield by increasing soil pH and soil quality in acidic soil

Non -flooded cultivation is a potentially water -saving practice for rice production. However, the response of rice yield and soil quality to long-term non -flooded cultivation and straw return on acidic soils have not been comprehensively revealed. The long-term effects were assessed by a 20 -year field experiment that with water regimes (traditional flooded and non -flooded cultivation) as main plots and straw managements (straw return and no straw return) as sub -plots. Compared with traditional flooded cultivation, non -flooded cultivation maintained soil quality, rice yield, and yield sustainability and presented higher water productivity. Straw return management significantly increased the 20 -year averaged rice yield by 4.4% under traditional flooded cultivation and 5.4% under non -flooded cultivation compared to no straw return management. Soil pH was the most correlated factor that affected rice yield and was correlated positively with rice yield (R2 = 0.11, p = 0.001). Non -flooded cultivation increased soil pH by 2.0% and Olsen -P by 26.9% and decreased soil total N by 7.7% and NH4OAc-exchangeable K by 11.1% compared with that of traditional flooded cultivation. Compared to no straw return management, straw return management increased soil total N, Olsen -P, and NH4OAc-exchangeable K by 10.0%, 16.5%, and 19.9%, respectively. Overall, straw management under non -flooded cultivation achieved the highest soil quality index and was correlated positively with rice yield (R2 = 0.53, p = 0.007). Therefore, nonflooded cultivation combined with straw return management is a sustainable agricultural strategy for conserving irrigation water and maintaining crop yields and soil quality.