The Impact of Spatial Variation on the Macronutrient Availability in the Soil of the Al-Rifai District, Dhi-Qar Province

Abstract

Abstract This research was conducted in the southern Iraqi district of Al-Rifai, Dhi Qar Province. Ten pedons were identified in the Al-Rifai District, which is situated in the northern region of Dhi Qar Province and is 63 kilometres from the centre of Nasiriyah. Its longitude ranges from 46°11′10.21″ to 46°21′45.98″ and its latitude is from 31°44′38.835″ to 31°46′ 9.889″. Of these pedons, eight contain wheat and barley crops, fodder crops, and palm trees. Two pedons contain abandoned, uncultivated soils. The results were acquired after the locations of the pedons were detected and their locations were determined using a GPS positioning programme. For laboratory analysis, samples collected from each site were deposited in containers, numbered, and transported to the laboratory. Based on the findings, the pedons grown with wheat, specifically pedon P6, exhibited the highest values of available nitrogen in soil (26.90 mg kg−1). The uncultivated pedons, denoted as pedons P9 and P10, contained the maximum concentrations of available phosphorus in the soil at 20.18 and 19.60 mg kg−1, respectively. In contrast, pedons P8 and P7 contained the lowest concentrations at 16.17 and 15.26 mg kg−1, respectively. Pedons P9 and P10, which correspond to the uncultivated pedons, contained the lowest value of available phosphorus in the soil. Conversely, pedon P8, which represented the uncultivated pedons, contained the highest value of available potassium in the soil, amounting to 185.18 mg kg−1. P9 and P10 exhibit the least amount of available potassium in the soil, measuring 162.61 and 159.81 mg kg−1, respectively.