Effect Of Soil Management And Fertilization On Growth, Yield And Fruit Quality Of Blueberry

In this study, a field experiment was conducted to investigate the effects of nitrogen (N) fertilization, potassium (K) fertilization and their application rate on the growth,yield and quality of5-year-old northern highbush blueberries’Bluecrop’(Vaccinium corymbosum L., Blueberry). The experiments of changing soil pH value were conducted in pots by applying sulfur powders for finding the influence of soil pH on plant nutrients and fruit quality. The study aimed at clarifying the effects of fertilizing regime and reducing the soil pH on the growth, fruit yield and quality of blueberry.1. During annual growth cycle of blueberry, N content in leaves had a downward trend, N elements absorption was the fastest between the flowering to harvest period, K content in leaves had a decreased first and then increased trend later.2. The application of N fertilizer on blueberry yield and some fruit quality showed significant effects, no significant effect on leaf nitrogen content. Within a certain range of N fertilizer (10to20g/plant) could significantly improve the fruit content of soluble sugars, anthocyanins,flavonoids,total phenols and other active ingredients, but the yield was decreased; excess application (30g/plants■(NH4)2SO4) reduced fruit quality, and inhibited flower bud differentiation. Adding N fertilizer improved the N content of the branches significantly, and showed a trend that increased and then decreased with the increasing of N application. The optimum N application rate was20g/plant (NH4)2SO4.3. K fertilizer could significantly increase the K content in the leaves, but the application period improved the K. content in leaves was not obvious. Fertilization time had no significant effect on fruit weight and yield per plant; and could significantly improved fruit anthocyanins, total phenols and sugar content,the sooner applied the more could be fully used. But too much K fertilizer reduced the anthocyanins and sugar content. The optimum potassium application rate was30of K2SO4per plant and applied at the young fruit period, one-time application at young fruit period was better than twice or applied at promote mature period.4. The soil pH value at each sampling period was decreased with the increasing amount of applied sulfur powder, soil pH was significantly negatively correlated with sulfur powder application amount. After applied about70days, the soil pH became stable, in addition to the two largest application amount of sulfur powder, the soil pH value remained between3.5to4.5for about200d (December26).