Efficiency of phosphate fertilizers containing growth promoters in plant fertilization

Optimizing water and nutrient absorption in plants can be achieved through a practical strategy: the combination of plant growth promoters (PGPs) with phosphate fertilizers. This synergistic approach holds promise for enhancing agricultural productivity and sustainability. The objectives of this work were to produce new phosphate fertilizers containing PGPs and to evaluate the efficiency in promoting the growth of the roots and shoots and increased phosphorus (P) uptake of plants. The fertilizers produced contained reactive natural phosphate rock from Morocco and PGPs indole-3-butyric acid, humic substances or Trichoderma afroharzianum, and a control fertilizer, without adding PGPs. The agronomic efficiency of this fertilizers were evaluated in two contrasting soils. The additional treatment with the monoammonium phosphate was included. The experimental unit consisted of rhyzobox containing 350 cm3 of soil, where a soybean plant was grown. Thirty days after sowing, the root length, average root diameter, root tips, and fine roots were measured using WinRHIZO software. The dry matter and P content of the roots and shoots were determined. PGPs have a great potential to increase the efficiency of P absorption by plants and the photosynthetic rate, and have a great potential to increase phosphorus use efficiency. The effects of PGPs were observed in the architecture of the root system, leaf area, and increased P content by plants. In sandy soil, the application of phosphate rock containing humic substances, Trichoderma afroharzianum, and indole-3-butyric increases the total phosphorus uptake by 26.5%, 16.3%, and 12.2%, respectively.