Distribution of soil salt and pollution of nitrate and boron of different depths affecting wheat and rice yields in the Khuzestan province

Soil macro- and micro-nutrients can importantly affect wheat and rice tolerance in salt stressed conditions. The objective was to investigate salt distribution and pollution of nitrate and boron, resulted by chemical fertilization, in the non-alkaline and arid area of Khuzestan province, affecting wheat (Chamran genotype) and rice (Anbarbou genotype) yield. The research was conducted in the regions of Arab Asad (region 1) and Veis (region 2) and soil samples were collected from five different stations, in four different seasons and from the depths of 0-30, 30-60, 60-9-, and 90-120, and their salinity, and concentrations of nitrate and boron were determined. According to the results, for region 1, soil salinity at different depths was in the range of 1.96-5.16 dS/m, and for region 2 it was in the range of 1.90-4.92 dS/m. The highest nitrate concentrations for different depths were equal to 13.5, 18, 8.5, and 9 ppm (region 1) and 12.5, 16, 10, and 7 ppm (region 2). The corresponding values for boron were equal to 37, 49, 27 and 23.5 (region 1), and 37.5, 48, 28, and 24 (region 2). Increased levels of salinity decreased the yield of the two crops as wheat yield decreased by 17.8% (region 1) and 15.9% (region 2), and rice yield by 12.9% (region 1), and 14.4% (region 2). Investigating the distribution of salt, nitrate and boron in wheat and rice fields can be beneficial for the farmers to favorably use the present resources for optimum yield production.