The effects of organic amendments on mineral element uptake and fruit quality of raspberries

The organic produce industry is gaining popularity with consumers because of the perception for healthier foods and the environmental benefits of this agricultural practice. Common amendments in organic agriculture include compost and compost tea, the latter being a relatively new product in North America. The main objective of this study was to assess the effectiveness of ruminant and municipal solid waste compost and compost teas made from these composts on selected soil, leaf and fruit parameters of raspberries. Generally, foliar compost tea application was as effective as compost addition in raspberry production. Concentrations of K in leaf and fruits were significantly lower (p = 0.05) in compost tea treated raspberries. Furthermore, the compost tea increased leaf Na compared to compost amendments which suggested that raspberries preferentially take up Na via foliar applications compared to root Na applications. The yield, total antioxidant capacity of fruit, and vitamin C content of fruit were not affected by treatment but differed greatly among years. Precipitation also varied greatly among years as did soil nutrient concentrations and may have influenced yield, total antioxidant capacity, and vitamin C content.