Knowledge of the amount of nutrients in soil is required to achieve sustainable management. The objective of this study was to assess the variability of soil-available and single-point buffering index of phosphorus (P) in the farmlands of the Khoy region, Iran. Composite soil samples (0-30 cm) were collected at 114 locations on regular grid of 1000 m. Some soil physico-chemical characteristics such as soil texture, soil organic matter (OM) content, soil pH, electrical conductivity (EC), calcium carbonate equivalent (CCE), available P (P ava ) and single-point P sorption index (PSI) were measured. Results showed that all variables in this study have spatial distribution in the effective range of 1500-4800 m. Moreover, experimental semivariograms of all studied variables were best-fit by spherical and exponential models. Most importantly, kriged maps revealed that a major part of the study area contains high P ava , which is seemingly due to the frequent application of phosphate fertilizers along with poultry manure. Some soils in the western part showed low PSI index; they therefore need more P fertilizer application. In addition, due to the lower PSI value in the eastern half of the study region, applying less fertilizer at more frequent intervals seems to be more beneficial than larger single applications. Eventually, to reduce environmental risks and prevent the loss of natural resources, the method of applying P fertilizer needs to be mainly based on the created PSI distribution map.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.