Effect of nitrogen and sulfur combinations on spring wheat (Triticum aestivum) growth, yield, and soil nutrient availability in a greenhouse experiment

Effective management of nitrogen (N) and sulfur (S) is crucial for maximizing spring wheat productivity, as both nutrients play key roles in improving growth, yield attributes, grain protein content, and soil fertility. Despite their importance, determining the optimal application rates of N and S for enhanced wheat performance remains a challenge. This study was conducted as a pot experiment under controlled greenhouse conditions, with 12 treatments replicated three times and carried out over 85 days. The treatments included a control (0N + 0S), nitrogen-only treatments (40N + 0S, 80N + 0S, 120N + 0S), sulfur-only treatments (30S, 60S), and combined N and S treatments (40N + 30S, 80N + 30S, 120N + 30S, 40N + 60S, 80N + 60S, 120N + 60S). The results revealed that the application of 120N + 60S significantly improved key growth parameters such as plant height, grains per spike, spike density (spike/m²), and 1000-grain weight. This treatment also resulted in higher grain nitrogen content, N uptake, and protein levels, confirming its superiority over other treatments. Additionally, post-harvest soil analysis indicated increased mineral N and available S levels, while showing a slight decrease in pH and an increase in electrical conductivity (EC). In conclusion, the 120N + 60S combination was identified as the most effective treatment for maximizing wheat yield, improving grain quality, and enhancing soil nutrient availability. However, it is recommended that future studies validate these findings under field conditions, across different soil types and climates, to ensure broader applicability of 120N + 60S as a best practice for wheat cultivation.