Phosphorus (P) is an essential nutrient for snap bean growth, directly influencing root development, plant health, and overall yield. However, P bioavailability is often limited by soil fixation, particularly in highly acidic and alkaline environments. In the Hastings region, soil pH can drop to 4.7 during the growing season, leading to substantial P immobilization due to high concentrations of extractable aluminum (1,300–2,000 lbs/acre) and iron (250–600 lbs/acre). These metals readily react with P, forming insoluble complexes that restrict plant uptake. Chemically, one pound of aluminum can fix up to 2.6 pounds of phosphorus pentoxide, significantly reducing P availability for crop growth. Conversely, in the Homestead region, where soil pH reaches 8.4, P fixation occurs primarily through reactions with calcium, with one pound of calcium binding approximately 1.2 pounds of phosphorus pentoxide, further limiting P solubility. Conventional P fertilization typically relies on a single pre-plant application, which does not align with the plant’s continuous nutrient demands throughout the growing season. Moreover, prolonged soil-P interaction exacerbates fixation losses, further reducing bioavailable P. This study investigates the effectiveness of split P applications as a strategy to mitigate fixation and improve nutrient uptake efficiency. By minimizing phosphorus’s contact time with reactive metals, split applications—through multiple dry granular P applications or fertigation—help sustain adequate P concentrations in plant tissue. Preliminary results indicate that split applications significantly enhance P uptake and use efficiency, leading to higher snap bean yields compared to conventional single-dose treatments. These findings suggest that split P applications offer a more effective and sustainable approach to optimizing phosphorus management in snap bean and other vegetable production.
