Nutritional and Bread-Making Quality of Wheat as Influenced by Mineral Fertilization in a Compost-Amended Regosol soil

This experiment was conducted to assess the effect of different levels of nitrogen (N), phosphorus (P) and potassium (K) fertilization on growth, grain yield, nutritional and bread-making quality of wheat in a compost-amended regosol soil. Wheat cultivar Minaminokaori was grown in containers containing a mixture of regosol and aerobic compost (2:1 v/v). This study comprised a non-fertilized control (F1) and six levels of NPK fertilizers: F2 (80 kg N + 40 kg P2O5 +40 kg K2O ha-1), F3 (110 kg N + 60 kg P2O5 + 55 kg K2O ha-1), F4 (140 kg N + 80 kg P2O5 + 70 kg K2O ha-1), F5 (170 kg N + 100 kg P2O5 + 85 kg K2O ha-1), F6 (200 kg N + 120 kg P2O5 + 100 kg K2O ha-1) and F7 (230 kg N + 140 kg P2O5 + 115 K2O kg ha-1). A significant improvement in agronomic performance, grain nutritional and bread-making quality of wheat was observed with the F6 treatment, it increased the grain yield (151.6%), crude protein (65.3%), water-soluble pentosan (40.5%), and dry gluten (4-fold) compared to the control. The F6 treatment also increased grain total N, P, K, Mg, Ca, Zn and inorganic phosphorus contents by 65.2, 33.6, 8.9, 19.7, 165.9, 26.1 and 80.0%, respectively, compared to control. However, it slightly increased grain phytate P content. The results from this study suggest that agronomic performance, grain yield, nutritional and bread-making quality of wheat can be improved with an appropriate dose of NPK in a compost-amended regosol soil.