Abstract:

To investigate the impact of organic fertilizer on soil quality, as well as apple crop yield and quality, a study was conducted utilizing soil testing and formula fertilization. Organic fertilizer was substituted for chemical fertilizer at varying proportions of 10%, 20%, 30% and 50%. The study examined the effects of these treatments on soil nutrients, apple orchard yield, and fruit quality. The results indicated that employing soil testing fertilizer formulas and partially replacing chemical fertilizer with organic fertilizer led to a significant increase in apple yield. The combined application of organic fertilizers also enhanced the firmness of apple fruits, resulting in an increase in hardness ranging from 2.27% to 2.90% compared to the control group (T₁). Notably, there were no significant changes in total phosphorus and potassium levels in the fruit. Furthermore, as the amount of organic fertilizer applied increased, both the soil organic matter and alkali-hydrolyzed nitrogen content also rose. Specifically, organic matter content ranged from 20.2 to 25.7 g/kg, while alkali-hydrolyzed nitrogen content varied from 74.7 to 96.7 mg/kg. Spearman correlation analysis revealed a significant relationship between apple yield and soil organic matter, as well as available phosphorus content. Additionally, fruit firmness was found to correlate with pH and organic matter levels. Therefore, substituting a portion of chemical fertilizer with organic fertilizer can enhance soil nutrient levels, such as organic matter, thereby improving apple yield and quality.

Key words: apple, soil improvement, organic fertilizer, substitute, yield, quality, soil testing and formula fertilization