Nutrient extraction by forage sorghum varieties irrigated with saline fish farming effluent

The use of water with high levels of salts may cause nutritional imbalance and reduction in crop productivity. In this context, the objective of the work was to evaluate the nutrient extraction of three varieties of forage sorghum cultivated under different irrigation slopes with saline effluent from pisciculture. The experiment was conducted under field conditions, and the treatments came from a 3x4 factorial scheme, with three varieties of forage sorghum (Volumax, F305 and Sudan) and four leaching fractions (0; 5; 10 and 15%), arranged in subdivided plots with four blocks. The plots were composed by the leaching fractions and the subplots by the varieties. At 93 days after planting, 10 plants were collected to determine dry matter production and N, P, K, Ca, Mg, Na, Fe, Cu, Zn, and Mn contents. The total extracted and the distribution of nutrients in the plant were evaluated. The F305 variety extracted intermediate amounts of nutrients in relation to the others, being the Sudao variety the one that presented the greatest extraction. The use of leaching fraction influences the amount of nutrients extracted, altering their distribution in the different parts of the forage sorghum plant.