Nutrition of conilon coffee under fertilization of nitrogen and molybdenum

Abstract

Nitrogen (N) is the most applied nutrient in Coffea canephora crop. However, the absorption of N, especially in the form of nitrate, does not guarantee its effective use in the synthesis of biomolecules. The reduction of nitrate in the cytosol is often limited by the deficiency of molybdenum (Mo). This study, conducted during two coffee production cycles under field conditions, aimed to evaluate the effects of applying Mo on the nutrition of Conilon coffee subjected to doses of N. The experimental design used was in randomized blocks, in a 2 x 5 factorial scheme, the first factor being the absence and presence of molybdic fertilization and the second factor, N doses (300, 500, 700, 900 and 1,100 kg ha−1 year−1). Increasing doses of N promoted a linear increase in S, and within certain limits, increased the concentrations of N-NH4 +, P, K and Ca in coffee leaves; while there was a decrease in the levels of Mg and Mo. The sodium molybdate fertilizer applied to the soil was efficient in supplying Mo to the coffee. Although the Conilon maintains basal levels of nitrate in the leaves, molybdic fertilization prevented the excessive accumulation of NO3 - in plants submitted to N doses above 515 kg ha−1. In the second year, the highest concentrations of N-NH4 +, P, K and Ca were achieved with doses of N between 698 and 967 kg ha−1, which provided yield greater than 145 bags ha−1.