Optimizing Wheat Production: Effects of Alginate Oligosaccharide under Limited Nitrogen Fertilization

This study investigated the effect of alginate oligosaccharide (Algo) on wheat yield and nitrogen fertilizer optimization over two winter seasons (2020-21 and 2021-22). Algo, an environmentally friendly biostimulant, was applied as a foliar spray during the vegetative growth phase at four different concentrations, in conjunction with three nitrogen application rates-100%, 83%, and 65% of the recommended levels. The results demonstrated that the application of Algo, in combination with nitrogen fertilization, significantly enhanced various agronomic traits, including plant height, spike length, number of spikelets per spike, and the protein and carbohydrate content of wheat grains. Notably, the combination of nitrogen fertilization at 83% and 65% of the recommended rate with a foliar application of 25 mg L^–1 Algo led to increases in grain yield of approximately 17% and 10%, respectively, compared to the control group receiving 100% nitrogen without Algo. These findings suggest that the application of 25 mg L^–1 Algo in conjunction with 83% of the recommended nitrogen rate is the most effective treatment. This approach not only reduces nitrogen input but also achieves optimal performance across all measured parameters.