Corn and grass integrated system fertilized with multiple nutrients source.

Providing an adequate nutrients supply is important for high yields in crop-livestock integrated systems (CLIS). This research aims to evaluate K sources fertilizer's effect on corn Piata grass yield and nutritional status in the CLFIS. A two-growing season field experiment was carried out in a Typic Hapludox. The CLFIS was sown with corn together with Piata grass. Treatments comprised two K sources: polyhalite (14%-K2O, 19%-S, 3.6%-Mg, and 12.1%-Ca), and KCl (60% K2O) and five ratios of polyhalite: KCl (0:100%; 12.5:87.5%; 50:50%; 87.5:12.5%; 100%) and a control. The treatments were applied in the sowing and topdressing fertilization of corn. Piata grass used residual soil fertilization for growth. The best results of corn dry matter yield and Piata grass were obtained with polyhalite ratios. These values were significantly (p<0.05) higher than the best yield obtained in control (without fertilization). The treatments were also efficient in increasing S in soil and exporting K, Mg, and S by corn. This study showed polyhalite as an alternative source of K, Ca, Mg, and S and can meet the nutritional requirements of annual crops and pastures in a CLIFS.