Phosphate Glass-Based Controlled-Release Fertilizers Improve Wheat Growth, Yield and Grain Nutritional Quality Under Field Conditions

The controlled release fertilizers, such as phosphate glass fertilizers (GF), constitute the future of the chemical fertilizers industry. This study focuses on the evaluation of agronomic potential of three phosphate glass formulations, GF1, GF2 and GF3, presenting different compositions of macro- and micronutrients and which were produced as controlled release fertilizers to be applied for wheat crop. We investigated the effect of the three formulations of GF on wheat growth, yield, photosynthesis and grain quality as well as soil mineral status. A field experiment was performed using eight treatments: control, conventional chemical fertilizers (NPK) and three GF compositions (GF1, GF2, and GF3) with or without chemical nitrogen (N) supplementation. The results revealed that the application of different fertilizers had no evident effect on soil pH and electrical conductivity (EC) except for GF2 and GF2 + N treatments which presented a slight decline in soil pH and a great increase in soil EC compared to NPK treatment. Furthermore, soil supplemented with the different GF formulas showed an improvement on its mineral nutrient concentrations, especially GF1 and GF2 compositions. In addition, the application of the GF formulas mainly improved growth, yield and photosynthetic parameters compared to the NPK treatment, especially with N supplementation. The greatest improvement values (up to 186%) were recorded for wheat biomass accumulation in plants treated with GF2 and GF3 formulations. The application of GF showed a positive effect on grain mineral, sugar and protein contents with the distinction of GF3 for mineral content (ca. 13% increase), GF1 for sugars content (ca. 7% increase) and GF2 for protein content (ca. 126% increase) compared to the control. Our findings highlight the important agronomic potential of the selected glass fertilizers particularly in improving yield and grain quality which makes them potential fertilizers for the agriculture sustainability in the future.