Spatial analysis of soil salinity in a mango irrigated area in semi-arid climate region

Abstract

The salinization of irrigated areas in the semi-arid region of Brazil causes major problem for fruit production. Defining the spatial distribution of soil salinity provides important insight technique for improving the management of irrigated fruit-production areas. This work aimed to (1) assess the spatial distribution of soil salinity and (2) delineate management zones in an irrigated mango orchard in the semi-arid region based on soil salinity data. The experimental site in Juazeiro County, Bahia state, Brazil was defined by two sample grids, one under the canopy of the mango trees and the other in the row spacing with 96 georeferenced points spaced 8 × 8 m apart. Disturbed-soil cores were taken from the 0 to 0.2 m layer at each point. Soil texture, electrical conductivity (EC), exchangeable cations, and soluble cations were determined. Data were analyzed using descriptive data and geostatistical analysis. Soil salinity showed spatial dependence for samples collected in the row spacing of the mango trees. Exchangeable Na, and soluble Na, Ca, and Mg were the attributes that best defined the spatial distribution of soil salinity. Three management zones in the studied area were defined based on soil EC values, in which 63% classified as salic, 34% saline and 3% non-saline. This study clearly shows that soil-salinity problems associated with the development of mango plants may be due to an accumulation of salts in the spacing region between the plants.