The Effect of Different Fertility Levels on Yields of Intensively Managed Coffee in Puerto Rico

Abstract

The effect of three levels each of nitrogen, phosphoric acid, and potash, on yields of intensively managed coffee grown in Alonso clay at Castañer were determined. Yields averaging in excess of 15 hundredweights of market coffee per acre were obtained over 3 successive years, compared to an Islandwide average of about 150 pounds. A marked response to the application of 150 pounds of nitrogen per acre occurred during all 3 years, with a strong indication of a response to an additional 150 pounds of nitrogen during the 2 years of normal rainfall. A strong response to the application of 150 pounds of potash per acre occurred during the first year, a response to the 300-pound application the second year, and to the 150- and 300-pound levels the third year. There was no significant response to phosphorus in any year.