Critical nutrient range and evaluation of nutritional status in coffee plantations of Minas Gerais

The critical nutrient range and the nutritional state of coffee (Coffea arabica) plantations, characterized by low, intermediate and high productivity, in four areas in Minas Gerais, Brazil, were studied during 1996/97-1998/99. Some 312 leaf samplesfrom 168 farms were collected during two consecutive years, one of which was characterized by high or low productivity based on the biennial cycle of the coffee trees. The macronutrient (N, P and K) and micronutrient (Cu, Fe, Zn, Mn and B) contents of the leaves were analysed. The critical nutrient range for the years of low and high productivity, and for each area was calculated based on the results obtained for farms of high productivity (more than 1800 kg/ha of green coffee averaged over the two consecutive years). The nutritional state of the plantations was categorized either as deficient, appropriate or excessive. The critical nutrient status did not vary between years and areas. Nutritional problems in relation to micronutrients were predominant.