Fertilizer requirements of coffee grown on Catalina clay in Puerto Rico

Abstract

The results obtained in two coffee fertilizer tests performed with the Puerto Rican variety of Coffea arabica on "Catalina Clay" are presented, statistically analyzed, and discussed. Nitrogen and phosphoric acid applications seem to be of greater importance as regards market-coffee production of the above variety in the soil type used, than are the applications of potash, which had no significant effects on the yields. These results are in sharp contrast with the results obtained by McClelland, who found potash applications to be essential and phosphoric acid applications to be not essential for maximum coffee production in Puerto Rico. It should be noted that McClelland's experiments were carried out on other soil types, which were probably not in condition to provide the coffee trees with their potash requirements.