Broccoli Cultivation Under Different Sources and Rates of Specialty Phosphorus Fertilizers in the Brazilian Cerrado

This study aimed to evaluate the agronomic performance and yield of broccoli grown under different sources and rates of specialty phosphorus (P) fertilizers in Uberaba, Minas Gerais, Brazil. The experiment was conducted in a randomized block design arranged in a split-plot scheme, testing three P sources: (1) conventional monoammonium phosphate (CMP); (2) polymer-coated monoammonium phosphate (PCMP); and (3) organomineral fertilizer (Org). Four application rates were evaluated: 0 (no P applied), 50% (200 kg ha⁻¹ of P₂O₅), 75% (300 kg ha⁻¹ of P₂O₅), and 100% (400 kg ha⁻¹ of P₂O₅) of the recommended phosphorus rate for broccoli, with four replications. The parameters assessed included plant nutritional status, soil fertility at harvest, number of leaves (NL), fresh head weight (FHW), dry head weight (DHW), and broccoli yield (YLD). In the first growing cycle, broccoli showed the highest NL (24), FHW (1.05 kg plant⁻¹), DHW (0.27 kg plant⁻¹), and YLD (18.81 Mg ha⁻¹) values when PCMP was applied, which was 5, 25, 8 and 23% higher than Org and 20, 25, 14 and 34% higher than CMP. In the second cycle, broccoli showed higher values of NL (23), FHW (1.85 kg plant⁻¹), DHW (0.26 kg plant⁻¹), and YLD (33.01 Mg ha⁻¹) where Org was applied, which was 4, 15, 8 and 5% higher than CMP and 2, 24, 4 and 14% higher than PCMP, respectively. All the variables evaluated showed the highest values at the 100% dose. Broccoli yield in the same area was 124%, 153%, and 115% higher in the second cycle compared to the first for CMP, PCMP, and Org, respectively. The greatest residual effect on soil fertility was observed in the area treated with the Org.