Assessment of soil fertility for wheat using combined Fuzzy and AHP techniques in Udham Singh Nagar of Uttarakhand, India

Assessing soil fertility is crucial for developing effective soil management strategies that can enhance soil health, increase crop productivity, and promote sustainable agricultural practices. The current study was conducted to assess the soil fertility index and, to prepare a soil fertility zonation map using combine fuzzy and analytical hierarchy process (AHP) approaches in Udham Singh Nagar of Uttarakhand. Sixty GPSbased surface soil samples were collected (0-30 cm depth) from different locations, and analyzed chemical properties using a stratified multistage random sampling method and maps were prepared to identify their spatial distribution. The results show that the values of soil fertility index on the fuzzy scale (0-1) was varied from 0.04-0.62 and, therefore, the study area was classified as very low, low, and moderate soil fertility classes comprising 55.61%, 44.24% and 0.14%, respectively. AHP analysis revealed that the most important limiting factor for wheat production was available nitrogen, followed by phosphorous, potassium, organic carbon, pH and electrical conductivity. A correlation coefficient between wheat yield and soil fertility index was found to be as high as 0.86, and its validating the zonation of soil fertility classes. This study infers that combined fuzzy-AHP techniques may be used to compute soil fertility index and limiting factors of wheat production.