Effect of Organic and Chemical Fertilizer Application on Apple Nutrient Content and Orchard Soil Condition

Apple cultivation in Japan typically involves the use of chemical fertilizers and pesticides which can damage the environment. Therefore, in this study we investigated the orchard soil biochemical characteristics as well as the fruit nutrient contents, and pesticide residues of apples grown either organically (organic fertilizers + reduced pesticides) or with conventional chemical fertilizers and pesticide rates. Compared with conventional chemical fertilizer treatment, the organic fertilizer treatment produced fruit with significantly higher contents of sugar, as well as soil with higher total carbon, total nitrogen, and total phosphorus. There were also significantly greater soil bacterial biomass and N circulation in the organically fertilized treatments. Minimal pesticide residues were detected in the organically fertilized fruits, but in the apples cultivated with conventional rates of fertilizers and pesticides there were significantly higher levels of propargite that was used to control spider mites. These residue levels from the conventionally fertilized orchards exceeded European and Codex residue standards. These results indicate that environmentally friendly arboricultural soil management practices, such as organic fertilizer and reduced pesticide cultivation can enhance nutrient cycling in soil, reduce the burden on the environment, and promote food safety and security.