YIELD DRY MATTER AND CONTENT OF CRUDE PROTEIN IN THREE TROPICAL GRASSES AT DIFFERENT LEVELS OF NITROGEN

Abstract

The present study was carried out in the Department of Animal Science of the University of Lavras, State of Minas Gerais, Brazil, in a dusky red latosol. The experiment started on 11/15/1990 and was completed on 05/29/1991. Its objective was to evaluate the yield and content of crude protein of transvala grass (Digitaria decumbens Stent cv Transvala), swazi grass (Digitaria swazilandensis Stent) and coastcross (Cynodon dactylon (L.) Pers. var. dactylon, Harlan, cv Coastal x Cynodon nlemfuensis Vanderyst var. robustus, Calyton & Harlan) grass under four different levels of nitrogen (0, 100, 200 and 400 kg/ha) as ammonium sulphate. The experimental design was randomized complete blocks with 6 replications. The treatments were distributed in split-split-plots design with the different grasses in main plots, nitrogen levels in split-plots and harvests in split-split-plots. Under those conditions the results showed that: 1) The application of nitrogen fertilizer increased the production of dry matter and crude protein; 2) Independently of the application of N, the coastcross grass was the one which presented the best performance in terms of yield and content crude protein of the grasses studied; 3) The swazi grass was slightly superior to the transavala grass in terms of yield and content crude protein.

KEY-WORDS: Nitrogen; fertilization; crude protein; dry matter; protein yield.