Evaluating the Effects of Phosphorus Levelsand Soil Moisture Conditions on Wheat Growth,Yield, and Quality in Semi-AridSouthern Punjab, Pakistan

Wheat is a crucial cereal crop worldwide, supplying significant calories, protein, and essential nutrients to the world's population.Its successful cultivation relies heavily on sufficient phosphorus availability in the soil, as this nutrient is vital for plant growth and metabolic functions.However, climate change has introduced challenges, such as irregular rainfall patterns and fluctuating soil moisture levels, which have impacted phosphorus availability and, consequently, wheat production.This study aimed to evaluate the effects of different phosphorus levels and soil moisture conditions on the growth, yield, and quality of wheat in the semi-arid regions of Southern Punjab, Pakistan.Six wheat cultivars, Faisalabad-2008, Galaxy-2013, Johar-2016, Gold-2016, Ujala-2016, and Borlaug-2016, were tested under varying phosphorus rates (0, 60, 70, 80, 90, and 100 kg P ha -1 ) and soil moisture regimes (15 to 65 kPa).Initial pot experiments showed that Galaxy-13 demonstrated superior growth and yield traits, including plant height (110.63 cm), tiller count (488 m -2 ), spike length (11.58 cm), spikelets per spike (20.00), grains per spike (49), 1000-grain weight (39.73 g), biological yield (12,729-12,764 kg/ha), total dry matter (1921.7 g m -2 ), grain yield (4980-4996 kg/ha), number of normal spikes (483 m -2 ), and leaf area index (5.13m/m), particularly at phosphorus levels of 90-100 kg P ha -1 .Although Gold-16 and FSD-2008 demonstrated lower grain carbohydrate content, FSD-2008 also displayed decreased grain moisture content, while Borlaug-16 had the lowest leaf area index.Johar-16 recorded the highest harvest index (40.03%),while Ujala-16 had the maximum number of sterile spikes (24 m -2 ), protein content (14.22%), carbohydrate content (55.10%), and seed moisture content (13.38%).The leaf area Pol.J. Environ.Stud.Vol.XX, No. X (XXXX), 1-13 duration in Galaxy-13 and Johar-16 reached approximately 213 m days per m, with crop growth rates of 18.46 g m -2 day -1 and net assimilation rates of 9.78 g m -2 day -1 .Although phosphorus application significantly increased grain yield, it also reduced grain protein content due to a dilution effect.This research highlighted the importance of phosphorus management for enhancing wheat performance, especially under climate-induced stress, and identified cultivars capable of sustaining productivity in drought-prone conditions.Results showed that Galaxy-13 is a highly promising cultivar for semiarid environments and provides actionable insights for improving sustainable wheat growth, yield, and quality through targeted phosphorus application, which may aid in cultivar selection in regions vulnerable to drought stress.