Feasibility of aerobic rice cropping development in Golestan province (Case study: Aq-Qala County)

Background and objectives: Golestan province is one of the 8 provinces exposed to drought in the country. For this reason, it was banned the cultivation of rice in Golestan province. On the other hand, in recent years, the tendency to cultivate rice has increased due to the greater economic benefits of this crop compared to other crops such as soybeans in this province. It seems that the first step to develop Aerobic field rice cultivation is to assess the environmental variables and land potential with agro-ecological requirements of this type of cultivation system. Therefore, changing the method of rice cultivation from lowland to aerobic system can be considered in maintaining the stability of rice production in Golestan. Considering of limitation of water resources in country especially in Golestan province, nowadays introduce a new agricultural system with low water consumption is very important. One of these systems is aerobic rice cropping. The aim of this study was to assess the land use suitability of a part of Golestan province (Aq-Qala County) for aerobic rice cropping development, using environmental variables assessment and spatial analysis in 2019.
Materials and methods: First, the agroecological requirements of an aerobic rice system determined using scientific sources and referring to pattern fields. Then, thematic maps of climate, topography, soil and water resources were provided in ArcGIS media. In continue, all layers overlaid based on Simple Limitation Method (SLM) and Boolean Logic. Finally, map of feasibility of aerobic rice cropping development for croplands of Aq-Qala County as a pilot region provided and classified.
Results: Feasibility results showed that only lands of south in Aq-Qala county had the suitable degree for aerobic rice cropping development (21,003.63 ha). According to land use suitable map, land capability degree was reduced from south to north of county. The marginally class (S3) had the highest area than other classes (36,965.61 ha). Results of fitness of Aq-Qala croplands with agroecological requirements of an aerobic rice system showed that about 26.73 percent of region was unsuitable for performance of this system. This region was located in the north of county, from east to east and found in Atrak watershed. Also, results of land use suitability according to Boolean Logic showed that 5.3 percent of region was suitable for aerobic rice cropping development, but 94.62 percent of croplands had the unsuitable degree (NS).
Conclusion: Generally, limitation variables of NS zone based on both of applied models were involved annual rain <300 mm, soil EC>7 dS/m, low amount of organic matter, high EC of surface water resources, unsuitable status of surface and ground water resources, SAR <12 of water resources and unsuitable pH.