NPK fertilization for high tree density coffee plantations

The NPK fertilization for high tree density coffee plantations, on an area basis, has been overestimated because it is derived from the recommendation for the traditional coffee blocks, on a tree basis. This research aimed at evaluating the NPK fertilization effects on two high tree density coffee plantations, one with the Mundo Novo variety e other with the Catuaí variety, under comercial production. Two 1/2(4 x 4 x 4) factorial experiments were conducted in coffee plantations under full production, in Santo Antônio and Samambaia farms, both at Mococa, State of São Paulo, Brazil. In the first farm, the coffee variety was Mundo Novo and the spacing was of 2.0 x 1.0 m. In the second case, the variety was Catuaí and the spacing was 1.5 x 1.0 m. The rates of nutrients applied were the following: nitrogen - 100, 200, 300 and 400 kg. ha-1 of N as urea; phosphorus - 0, 30, 60 and 90 kg. ha-1 of P2O5 as triple superphosphate; and, 0, 80, 160 and 240 kg. ha-1 of K2O as potassium chloride. The fertilization was split into four applications during the rainy season, starting in 1989. Four harvests were recorded for each location, from 1991 to 1994. At the Santo Antônio farm, the application of N reduced yields, which is unusual. In this case the initial soil sampling detect medium contents of P and high contents of K. The N leaf content was high for samples taken in 1992 and 1993. In the experiment at the Samambaia farm there was a significant effect of P fertilization, which is also unexpected. The results point to the need to fertilize coffee plantations taking into account the P and K contents of the soil and N contents of leaves. The results allow to conclude that coffee fertilization using standard NPK formulas, in higt tree density systems, can depress production when there is excess shade. Fertilizer needs should be determined taking into consideration soil analysis for P and K leaf analysis for N, and prescribing amounts to be applied on an area basis.

coffee tree; nitrogen; phosphorus; soil analysis; leaf analysis