Assessment of soil fertility index for potato production using integrated Fuzzy and AHP approaches, Northeast of Iran

Abstract

Considering the important role of soil fertility and nutrient management in the modernagriculture seems to be a key step in appropriate site-specific fertilizers management forcrop production. The present study was conducted to prepare a soil fertility zonation mapbased on soil nutrient elements including total nitrogen, available potassium andphosphorus, magnesium, manganese and iron and soil chemical parameters comprisingcation exchange capacity, organic carbon, salinity and pH by integrated Fuzzy and AHPapproaches for potato production in Rokh plain, northeast of Iran. In this regard the mostimportant soil chemical parameters and nutrient elements in 0-30 cm depth of the soilwas analyzed and mapped. The S-shaped fuzzy membership function was subsequentlydefined for each factor to fuzzify soil fertility parameters. The soil fertility map wasprepared by weighing factor layers by the AHP approach and summation of factor layersby IDW interpolation function in GIS. The values of the soil fertility index in the scale of 0to 1 ranged from 0.104 to 0.574, classified the study area in very low (922.90 km2), low(566.10 km2) and moderate fertility (14.86 km2) classes which comprises 61.37%, 37.64%and 0.99% of the surface area, respectively. A regression between soil fertility values andpotato yield in the study area revealed a high correlation (R2 = 0.91) between the observedresults which validate the zonation of the fertility classes in the region.