Wheat (Triticum aestivum) yield gap affected by soil physicochemical properties

Due to the important process of global warming, the improvement of soil factors, which decrease wheat (Triticum aestivum L.) yield gap, in the arid and semi-arid areas of the world including Iran (Kerman province) is of significance. The objective was to determine how wheat yield gap and yield components, in 15 different fields (three different locations with areas ranging from 2993 to 5175 km2), are affected by soil physicochemical properties including texture, electrical conductivity (EC), pH, soil organic carbon (SOC), total nitrogen (TN), available phosphorus (P) and potassium (K), and chemical fertilization. Wheat yield components including tiller and grain number, fertile spike, spike length, 1000-grain weight (25–44 g), plant height, biological yield (plant dry weight) (4880–14800 kg/ha), and plant density were measured. Linear regression analyses indicated that SOC (0.23–1.51%), TN (0.02–0.15%) and available K (195–280 mg/kg) significantly affected wheat yield and yield components, which were also positively and significantly correlated. There was a positive and significant correlation between SOC, TN, and available P and K, which were negatively and significantly correlated with EC. The regression models relating soil physicochemical properties with spike length and plant height were significant (P ≤ 0.05). The R2 values ranged from 0.54 (number of grains per spike) to 0.90 (plant height) and for economic (grain) and biological yields were equal to 0.75 and 0.83, respectively. The yield gap was in the range of 1245–4256 kg/ha. The improvement of soil physicochemical properties may decrease wheat yield gap in the arid and semi-arid areas of the world.