Influence of long-term application of N, P and K to coffee on some micronutrient contents

Analyses of soil samples collected from a long-term fertilizer trial receiving graded amount of N, P subíndice 2 O subíndice 5 and K subíndice 2 O ranging from 0-0-0 to 495-374-495 kg/ha. over a period of years revealed that continuous application of fertilizers brought down the soil pH significantly with concomitant increases in available Fe and Mn. Extractable Zn and Cu were not appreciably affected, possibly due to the presence of higher content of organic matter resulting in the complexation of these elements. Plant analyses indicated that leaf Mn increased considerably due to continuous manuring; no perceptible variations were noticed in leaf Fe and Cu. Leaf Zn gradually decreased with increasing doses of fertilizers