Biochar Application in Combination with No Tillage Enhanced Yield and Grain Quality of Ratoon Rice

Biochar is beneficial as a clean, stable, and efficient soil amendment to improve rice quality and yield. However, there are few reports on the effects of no-tillage in combination with biochar application on rice growth, yield, and quality in regenerative rice systems. This study evaluated rice yield, grain quality, multiple antioxidant enzyme activities, and malondialdehyde content under four treatments: rotary tillage alone, rotary tillage + biochar application, no-tillage alone, and no-tillage + biochar. The results showed that the rice yield under no-tillage alone was 15% lower than that under rotary tillage alone, but that biochar application significantly increased rice yield by 10% and 20% under rotary tillage and no-tillage conditions, respectively, which might be attributed to the fact that biochar application increased panicle number, spikelet number per panicle, grain filling rate, and antioxidant enzyme activities. Additionally, biochar application also increased fine rice rate and protein content, meanwhile reducing chalkiness degree and chalky grain rate in both the main-season rice and ratoon-season rice. These results suggest that biochar application could enhance the yield and grain quality of ratoon rice, thus compensating for the no-tillage-induced yield loss. This study reveals the role of biochar in main-season rice and ratoon rice cultivation, providing a valuable reference for improved fertilizer utilization and cleaner agricultural production.