| At present, apple planting area in Shaanxi Province is the largest in China. But the biggest problem in apple orchard is the lack of organic fertilizer resource and the low application rate of manure. In order to ensure the proper application of biogas slurry as organic fertilizer on apple, three methods including foliar spraying, irrigation and trunk smear, were employed to study the effects of biogas slurry application on apple orchards in Tongchuan Area, Shaanxi Province, China. The influences of different fertilization methods and amounts on nutrients of leaf and soil and apple quality were investigated. The results showed that compared with the control, irrigations of biogas slurry to young apple trees (30 kg per tree) and to full fruit trees (60 kg per tree) were remarkable to increase leaf nitrogen, phosphorus and potassium by 15.66%, 134.91%, and 45.83% in young trees, respectively, and 5.59%, 12.43%, and 28.65% in full fruit trees, respectively. Soluble solids and Vc concentrations became increased by 31.33%, and 27.38% in young trees, respectively, and 53.67% and 50.92% in full fruit trees, respectively. The most effective ratios of biogas slurry to water for spraying were 1∶2 on young apple trees and 1∶1 on full fruit apple trees. Smearing slurry on apple tree trunk had less impact on leaves nutrients and fruit quality. |