THE EFFECTS OF NITROGEN FERTILIZATION AND TIME OF CUTTING IN FIRST GROWTH IN BRACHIARIA BRIZANTHA ON YIELD, CRUDE PROTEIN CONTENT AND IN VITRO DIGESTIBILITY

The effects on dry Datter yield, crude protein content and in vitro digestibility of four different levels of nitrogen fertilizer application on almost pure Brachiaria brizantha were studied in two consecutive years. The levels were 0, 62.5, 125.0 and 187.5 kg N/ha, applied as ammonium sulphate. The results for the two years were significantly different for all parameters. Increased dry matter yield in response to increased N level was significant by the 1st harvest- year 1, but not until the 3rd harvest- year 2. Fertilizer N was rapidly taken up by the plants giving a maximum difference of 10 % at first harvest in both years. In vitro organic matter digestibility tended to increase from 1st to 3rd harvest in the first, but not the second year. Key words: N fertilizer, Brachiaria, yield, protein content, digestibility Under monsoonal conditions, reliable pasture production is limited to the periods of rain. In Tanzania (Morogoro region) pasture production is mainly based on natural bush savanna-grassland, and nitrogen deficiency is a typical condition. According to Madallali (1974), Brachiaria brizantha is one of the most promising species in Tanzania. At the university farm, a well maintained stand was available for research with the objectives of studying the response to nitrogen fertilization applied before th