Spatial correlation of nutrients in a typical soil-hickory system of southeastern China and its implication for site-specific fertilizer application

Abstract

Chinese hickory (Carya cathayensis Sarg.) is the most popularly edible nut in China. Currently, there is an increasing concern on the quality of Chinese hickory, due to soil degradation of hickory plantations. In this study, a total of 153 pairs of soil and Chinese-hickory-nut samples were collected from Lin’an city, a typical Chinese hickory producing area. The results showed that the average concentrations of soil available nitrogen (ANsoil), available phosphorus (APsoil), available potassium (AKsoil), and total nitrogen, phosphorus and potassium in nuts were 155.17, 14.04, 83.71 mg kg-1, and 106.64, 73.15, 374.16 mg kg-1, respectively. The APsoil concentrations in Chinese hickory plantation soils had a strong variability coefficient of 126.06%. More than 60% of the soil samples had low soil AP concentration with low pH values. The average concentrations of available boron (ABsoil), available Zinc (AZnsoil) and total manganese (TMnsoil) in soils were 0.26 mg kg-1, 1.14 mg kg-1 and 613.36 mg kg-1, respectively. The above mentioned micro-nutrients in soils of hickory plantation were low, especially the deficiency of B was obvious. The spatial patterns of the nutrients of hickory nuts were similar with that of soils to some extent, especially in their high- and low-values regions. Overall, the spatial cross-corregrams indicated that the quality of hickory nuts was greatly affected by APsoil, ABsoil, AZnsoil and TMnsoil. The results imply that the quality of hickory nuts is closely related to soil nutrients, such information can be further used to guide precision fertilization application in plantation management.