Abstract:

To clarify the effects of combined application of decomposed straw and biochar on soil nutrients，grape yield and quality，8 treatments were set up：CK（no fertilizer），T1（conventional fertilization），T2（low rate of conventional straw organic fertilizer），T3（high rate of conventional straw organic fertilizer），T4（low rate of new straw fertilizer A），T5（high rate of new straw fertilizer A），T6（low rate of new straw fertilizer B），and T7（high rate of new straw fertilizer B）. The results showed that T5 performed best in terms of yield per plant and single cluster weight，while also reducing titratable acidity and improving sugar-acid ratio. T6 significantly （p<0.05） increased total soluble sugar and vitamin C contents. Compared with CK，all treatments significantly affected soil pH value，organic matter content，available potassium content，available phosphorus content，and alkali-hydrolyzable nitrogen content. T3 was most effective in increasing organic matter content，while T7 performed better in raising soil pH value and alkali-hydrolyzable nitrogen content. Soil pH value showed significant negative correlations with available potassium content and available phosphorus content，while significant or highly significant （p<0.01） positive correlations were observed among organic matter content，available potassium content，available phosphorus content，and alkali-hydrolyzable nitrogen content. The study indicated that combined application of biochar and decomposed straw had positive effects on grape yield，quality，and soil physicochemical properties，but further optimization is needed to enhance the improvement effects on soil organic matter and nutrient contents. Future research should focus on optimizing amendment formulations and evaluating long-term effects to better guide grape cultivation and soil improvement practices.

Key words: grape, biochar, decomposed straw, soil fertility