Effects on Coffee of Two Levels of Fertilizer and Frequency of Their Application

Abstract

Experimental work was conducted at the Adjuntas Substation to determine the effect of frequency of application of two fertilizer levels on coffee grown both in full sunlight (unshaded) and under partial shade, the latter provided by trees of Inga vera Wild., planted 24 feet apart. The partial shade was estimated at 40 percent. The two formulations, 100-75-200 and 200-75-400 pounds per acre of nitrogen, phosphorus and potassium, respectively, were applied in one, two, four, and six applications per acre per year, and later evaluated. The combined statistical analysis of five experimental crops of coffee grown in full sunlight revealed that higher yields were obtained from the 200-75-400-pound formulation when applied in one, two, and six applications per acre per year than from the 100-75-200-pound formulation when applied in one or six applications. Higher yields were obtained from the 100-75-200-pound formulation when applied in two applications instead of one. No significant differences were found among the other treatments tested. The combined statistical analysis of five experimental crops of coffee grown under partial shade showed that higher yields were obtained from the 200-75-400-pound formulation when applied in four applications per acre per year than when the 100-75-200 formulation was applied in one application only. Hiere were no significant differences among the other treatments tested. The results make it advisable to use the 200-75-400-pound formulation of nitrogen, phosphorus and potassium, respectively, per acre per year, applied in two applications, when the coffee is grown in full sunlight under conditions typical of the Coffee Region. The 100-75-200-pound formulation applied to shaded coffee in two applications per acre per year apparently gives similar good results.