Doses de nitrogênio como determinantes na dinâmica populacional de perfilhos e acúmulo de forragem do capim-elefante anão cv. brs kurumi

Abstract

ABSTRACT

One of the factors related to the productive deficit of livestock on pasture is the low fertility of Brazilian soils, with emphasis on the low availability of Nitrogen (N). Given the need to apply fertilizers, especially Nitrogen as a form of intensification, this can promote substantial efficiency in the flow of biomass. In the literature, it is possible to find several studies relating the productive characteristics of elephant grass accord- ing to the need for nitrogen, since the genus Pennisetum perpureum Schum. is con- solidated as one of the most used in Brazil. N stimulates basilar tillering, which is na important aspect of elephant grass genotypes for cutting management. Finding na optimal balance of N utilization is important for a condition that promotes better tiller- ing dynamics. Thus, the objective of this work was to evaluate changes in the demo- graphic pattern of forage accumulation in dwarf elephant grass cv. BRS Kurumi sub- mitted to nitrogen fertilization splitting. It was carried out in a pasture area of the Sheep and Forage sector of CECA/UFAL. The treatments consisted of fractioning the fertilization with nitrogen of 300kg/ha applied in one, two, four and six doses, in the form of urea. For tillering demographic patterns, two clumps were randomly selected in each plot and identified with rings. Forage masses were estimated by collecting two samples from representative locations. The experimental data were analyzed according to regression, with 10% probability, by the t test. There was a positive line- ar effect (P<0.0000) in relation to the variables Tap P and TMP. Regarding the varia- bles TSP (P<0.0000) and DPP (P<0.0615) there was a negative linear effect, improv- ing density only after the sixth dose of N. The AF, LF E R/C showed a significantly positive linear response (P<0.0001) to the greater fractionation of fertilization, while the accumulation of CV obtained a negative linear response (P>0.0001) to the split- ting of N. the dwarf elephant grass BRS. cv. Kurumi showed better tillering dynamics when subjected to nitrogen fertilization in six applications of 50kg N/ha. Keywords: Penissetum perpureum schum. Tiller dynamics. Nitrogen fertilization. Ecophysiology.