CORN YIELD AS AFFECT BY NITROGEN FERTILIZATION ASSOCIATED WITH ACID WHEY

Abstract

Milk whey is an abundant residue that can be used for soil application, with particular interest in the N and K concentrations. This work aimed to evaluate soil chemical properties and corn yield in response to the combination of acid whey and N-urea topdressing doses. The experiment was carried out in Frutal/MG - Brazil, in a Haplustox. The experimental design was a randomized block with six replicates, and the treatments resulted from the factorial combination of five doses of N-urea (0, 45, 90, 135 and 180 kg ha(-1) N) in topdressing, with (62.500 L ha(-1)) or without whey. The use of whey increased the available P and the exchangeable K+ and Na+ in soil and there was vertical mobility of P, K+, and Na+ until 40-60 cm layer with the application of whey. The mineral N increased due to N fertilization, but not due to the application of whey. The whey in a dose that provided 50 kg ha(-1) N, increased the yield of maize in 938 kg ha(-1), which was not achieved with 180 kg ha(-1) N-urea in topdressing.