Response of black bean (<i>Phaseolus vulgaris</i> L.) to phosphorus fertilization in acidic and alkaline soils in Haiti

Haiti experiences one of the lowest yields of black bean (Phaseolus vulgaris) in the world (660 Kg/ha), although is the most consumed among all kind of beans. This is primarily due to poor soil and agronomic management, improper balance of soil nutrients, and limited fertilizer applications, which can lead to malnutrition, ecosystem degradation, and food insecurity, common to developing countries. Phosphorous (P) remains one of the major limitations for black bean production in both lowland and upland areas of Haiti. Included in nucleic acids, P plays a large role in plant reproduction and grain production. When soil does not have enough P available, it impacts plant growth and enhances micronutrient deficiencies, which will affect the physiological maturity. To evaluate black bean growth and yield, a pot study was conducted with two different soils (Kenscoff, acidic and Cabaret, alkaline) in Haiti using a completely randomized block design, replicated four times with four P rates (0, 44, 55, and 66 Kg/ha). Black bean in the alkaline soil achieved its highest yield when 55 Kg/ha was applied, and the acidic soil reached its optimum yield with the application of 44 Kg/ha. High amount of fertilizer is needed to meet the crop requirements, particularly when soil test P is low, especially when P can be potentially fixed by Fe or Al (acidic soil) or by Ca (alkaline soil). This study contributes to the first step in optimizing black bean production through better interpretation and nutrient recommendation of soil tests for Haitian soils.