PEACH

Treatment: CK, no fertilization, 0 kg/667 m2; SDH.2, Dahua PBOF, 2560 kg/667 m2; SDH.3, Dahua PBOF, 3840 kg/667 m2; SDH.4, Dahua PBOF, 5120 kg/667 m2; SKR.2, Kerui PBOF, 2560 kg/667 m2; SKR.3, Kerui PBOF, 3840 kg/667 m2; SKR.4, Kerui PBOF, 5120 kg/667 m2; SYT.2, Yite commercial organic fertilizer, 2,560 kg/667 m2; SYT.3, Yite commercial organic fertilizer, 3,840 kg/667 m2; SYT.4, Yite commercial organic fertilizer, 5,120 kg/667 m2.

Table 1 Effects of different fertilization treatments on peach fruit yield and quality.

Results: All fertilization treatments increased yield and SAR, with both yield and SAR rising as fertilization levels increased. SAR in SDH.4 and SKR.4 treatments was significantly higher than CK (p<0.05), but no significant differences existed among the three fertilizer types or different fertilization levels. Regarding yield, SDH.4, SKR.4, and SYT.4 treatments increased yield by 21.46%, 23.51%, and 27.82%, respectively, compared to CK. High fertilization (SDH.4, SKR.4, and SYT.4) significantly exceeded low fertilization (SDH.2, SKR.2, and SYT.2) (p<0.05). However, no significant differences in yield were observed among the three fertilizer types.

Table 2 Effects of different fertilization treatments on soil chemical properties.

Results: All fertilization treatments increased AN, AK, AP, and SOM compared to CK, but the effect on pH was weaker. There were no significant differences in AN, AP and SOM among three fertilizer types or fertilization levels. The AK of medium fertilization (syt. 3) and high fertilization (syt. 4) was significantly higher than that of low fertilization (syt. 2) . In addition, the AK of SDH. 4, SKR. 2, Syt. 3 and SYT. 4 treatments was significantly higher than that of CK. The pH of SYT. 3 treatment was significantly higher than that of SKR. 3 treatment (Table 2) .

Figure 2 Regulatory Mechanisms of Carbon Assimilation and Allocation in Peach Trees on Fruit Quality and Secondary Metabolism

Treatment: FA refers to the company's customized humic acid solution, while CK denotes the local farmers' fertilization plan.

Figure 3 Effect of Different Fertilization Treatments on the Color Change of Peach Fruit

Results: After applying Kangyuan humic acid, peaches exhibited more uniform color development and fuller fruit shape.