Soil Fertility and Nutritional State of Persimmon Rojo Brillante Plantations in the Ribera Alta (Valencia, Spain)

Soil fertility and nutritional state of persimmon (Diospyros kaki, cv. Rojo brillante), together with their relations to productivity, were studied for two growing seasons in 30 orchards within La Ribera Alta, the main persimmon-producing region in Spain. Soil and foliar samples were analyzed and the results were compared after dividing the orchards in two groups (high and low yield) according to their annual production. A general independence of crop yield from soil properties and fertility and nutritional states of trees was found, suggesting other factors such as health conditions or pruning procedures are probably more relevant for final production. Nevertheless, overabundance of available calcium or zinc deficiency seems to be associated with lower than average yields. In addition, the concentration of nutrients in leaves was measured monthly in two selected orchards during both seasons. The observed trends varied according to nutrient, orchard, and season but were in general comparable to those reported by other authors.