Qualitative Land Suitability Evaluation for Maize in Shahrekord Area Using FAO Method and ALES Program

Optimal land utilization is important because of land degradation due to incorrect use and ever-increasing need for increasing yield per surface area unit. For this optimal use، crop specific land suitability evaluation is essential. The aim of this research was qualitative land suitability evaluation for maize production in Shahrekord area and validation of the applied land suitability evaluation methods. In this regards، land suitability class was determined by matching land characteristics with maize growth requirements، using parametric method and ALES program. For model making in ALES program، simple limitation method was used، a data base including soil units، land characteristics and maize growth requirements was established in the program and then land characteristics were matched with the maize growth requirements. The results showed that as the square root formula of parametric method and the ALES program are used، most of the land units are classified as S2c. As the storie formula of the parametric method is used، because of multiplication of the suitability ratings and not due to land characteristics limitations، most of the land units are classified as S3c. The most important limiting factors for irrigated maize production in the study area are average minimum temperature and mean ratio of sunshine hours to day length of the growing cycle. In some of the land units، soil pH is considered as limiting factor as well.