Efeito de parcelamento da fertirrigação com N E K E salinidade do solo no crescimento inicial de cultivares de cafeeiro

Abstract

Irrigated coffee production has expanded because of the excellent results of techniques such as fertigation. It can provide rapid initial growth; however, the salinity of excessive nutrient solution can limit plant growth and cause plant mortality. N and K are mainly used in covering layers and their recommended doses are 4 gplant-1 month-1. This study aimed to assess the initial growth of 'catuaí' and 'catucaí' coffee plants and soil salinity resulting from fertigation with N (urea) and K (KCl) according to the indicated doses and fractionated every 2, 4, 6 and 8 weeks. The experiment was carried out in a greenhouse of UFLA/DEG, Lavras-MG, Brazil, where 13-l vases were irrigated under soil water tensions between 20 and 30 kpa during 24 weeks. The following were evaluated: CE fertilizer solution and CE soil solution, plant height and shoot diameter after 8-week cycles. Results indicated that the used fertilizer dose was excessive, causing plant death after 2 cycles, except for the control. These varieties resisted soil salinity (CEea = 1.2 ds m-1). Despite the CE of the applied fertilizer solution be high, the results were higher than those of similar studies with NaCl solution to lower salinity levels.