Resumo

COSTA, N. de L. et al. Chemical composition and nutrients extraction of Trachypogon plumosus under fertilization and regrowth ages. Arch. zootec. [online]. 2013, vol.62, n.238, pp.227-238. ISSN 1885-4494.  https://dx.doi.org/10.4321/S0004-05922013000200008.

In pasture management, the availability of soil nutrients, and use of adequate rest periods, consistent with the grass morphological and physiological characteristics, are important factors for obtaining high quality forage and, consequently, satisfactory levels of animal production. To evaluate the effects of soil fertility correction (control, liming, fertilization and liming + fertilization) and regrowth ages (28, 42, 56, 70 and 84 days) on chemical composition and nutrient extraction of Trachypogon plumosus in the Roraima's savannas. The nitrogen, phosphorus, calcium, magnesium and potassium contents were inversely proportional to regrowth ages, while cell wall components increased consistently with regrowth ages. The highest N and K contents were recorded with fertilization or liming + fertilization, while control or liming alone provided higher P, Ca and Mg contents. Regrowth ages promoted quadratics effects on nutrients extraction and maximum values were estimated at 67.8 (26.71 kg ha^-1 of N), 63.4 (2.82 kg ha^-1 of P), 62.9 (5.17 kg ha^-1 of Ca), 68.4 (3.32 kg ha^-1 de Mg) and 66.0 days (12.71 kg ha^-1 of K). The nutrient extraction by the grass followed the decreasing order: N > K > Ca > Mg > P. Fertilization and liming + fertilization improved nutrients extraction and forage quality with lower fiber contents.

Palavras-chave : Acid detergent fiber; Calcium; Magnesium; Neutral detergent fiber; Nitrogen; Phosphorus; Potassium.

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