FERTILIZATION OF YOUNG ARABICA COFFEE PLA NTATIONS IN CAMEROON

Mineral fertilization trials were carried out in young Arabica coffee plantations in Cameroon to determine the effect of applying different chemical elements on young plant growth. At Foumbot, on a fertile soil of recent volcanic origin, applying nitrogen had a favourable effect on the growth of young coffee trees and on yields. Applying potassium or magnesium can adversely affect the growth and productivity of young coffee trees. Phosphorus or calcium applications had no effect. The m ost effective treatment was to apply at least 400 kg of ammonia sulpha te per hectare over the first five years. At Santa, on a highly desatu rated soil, only nitrogen had a favourable effect on the growth of you ng coffee bushes. Potassium applications reduced the proportion of fru its affected by coffee berry disease and increased yields. Nitrogen ca nnot have a favourable effect on yields unless tree potassium nutritio n is improved. The most effective fertilizer formula corresponded to a n application of one to two units of potash for one unit of nitrogen.