Feasibility of wheat-canola rotation performance in agricultural lands of Bandar-Torkman and Gomishan townshipsusing Geographic Information System (GIS)

In order to assess wheat-canola rotation performance in agricultural lands of Bandar-Torkman and Gomishan townships, Geographic Information System (GIS) and overlay method were used to match the environmental requirements of crops and characteristics of land. Firstly, agroecological requirements of wheat and canola were identified from scientific literatures and classified. Studied environmental components were as climate (annual precipitation, spring precipitation, annual mean temperature, spring mean temperature, annual minimum temperature, spring minimum temperature, annual maximum temperature and spring maximum temperature) and soil characteristics (EC, organic matter and pH). After adding weights to digital environmental layers, these layers overlaid and integrated in GIS media separately for wheat and canola, and then land use suitability maps of wheat and canola cultivation were obtained. By combining these two maps and reclassifying into 4 classes including very suitable to unsuitable, wheat-canola rotation suitability map was produced. Results showed that 13.65 and 30.92% of areas were high suitable and relatively suitable for performance of wheat-canola rotation, that are located in southern and south townships. These zones had enough rainfall, suitable EC and organic matter content. The less suitable and non-suitable regions were 15.65 and 39.78%, that are located in northern and eastern of studied area. In general, high salinity soils (>12 dS m^-1), low levels of spring precipitation and low amount of soil organic matter, were introduced as limitation factors in performance of wheat-canola rotation in these regions.