Pesquisa Agropecuária Tropical (Aug 2010)

BIOMASS DECOMPOSITION AND NUTRIENT RELEASE OF BRACHIARIA AND GUINEA GRASS UNDER BRAZILIAN SAVANNAH CONDITIONS DECOMPOSIÇÃO DA BIOMASSA E LIBERAÇÃO DE NUTRIENTES DOS CAPINS BRAQUIÁRIA E MOMBAÇA, EM CONDIÇÕES DE CERRADO

  • Tatiely Gomes Bernardes,
  • Pedro Marques da Silveira,
  • Marcos Antônio Machado Mesquita,
  • Renata Alves de Aguiar,
  • Glaucia Machado Mesquita

DOI
https://doi.org/10.5216/pat.v40i3.5584
Journal volume & issue
Vol. 40, no. 3

Abstract

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<p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="pt-BR" align="JUSTIFY"><span style="color: #000000;"><span><span style="font-size: x-small;"><span style="font-size: x-small;"><span style="font-size: small;">The objective of this research was to evaluate the accumulation and release of nutrients from the dry biomass of brachiaria (</span></span><span style="font-size: x-small;"><span style="font-size: small;"><em>Brachiaria brizantha</em></span></span><span style="font-size: x-small;"><span style="font-size: small;">) and guinea grass (</span></span><span style="font-size: x-small;"><span style="font-size: small;"><em>Panicum maximum</em></span></span><span style="font-size: x-small;"><span style="font-size: small;">) used as cover crops in a no-tillage system, under </span></span><span style="font-size: small;">Brazilian savannah</span><span style="font-size: x-small;"><span style="font-size: small;"> conditions. The experiment was carried out at Embrapa Arroz e Feij&atilde;o (Fazenda Capivara), in Santo Ant&ocirc;nio de Goi&aacute;s, Goi&aacute;s State, Brazil, in a dystrophic Red Oxisol. A randomized block design, with four repetitions, in a split plot scheme in time, was adopted. At the flowering stage, plants were cut and kept on the soil, and the productivity of dry biomass, and nutrient accumulation, decomposition and liberation were evaluated at 0, 15, 30, 45, 60, and 75 days. The biomass yield was 16,643 kg ha</span></span><span style="font-size: x-small;"><sup><span style="font-size: small;">-1</span></sup></span><span style="font-size: x-small;"><span style="font-size: small;">, for brachiaria, and 18,244 kg ha</span></span><span style="font-size: x-small;"><sup><span style="font-size: small;">-1</span></sup></span><span style="font-size: x-small;"><span style="font-size: small;">, for guinea grass. For both cover crops, N was the most accumulated nutrient. Among the macronutrients, K showed the highest release rate (70% and 59%, respectively for guinea grass and brachiaria).</span></span></span></span></span></p> <p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="pt-BR" align="JUSTIFY"><span style="color: #000000;"><span><span style="font-size: x-small;"><span style="font-size: small;"><span lang="en-US">KEY-WORDS: </span></span><span style="font-size: small;"><span lang="en-US"><em>Brachiaria brizantha</em></span></span><span style="font-size: small;"><span lang="en-US">;</span></span><span style="font-size: small;"><span lang="en-US"><em> Panicum maximum</em></span></span><span style="font-size: small;"><span lang="en-US">; decomposition rate; macronutrients accumulation; no-</span></span><span style="font-size: x-small;"><span style="font-size: small;"><span lang="en-US">tillage system.</span></span></span></span></span></span></p> <p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="pt-BR" align="JUSTIFY"><span style="color: #000000;"><span><span style="font-size: small;">O objetivo deste trabalho foi avaliar o ac&uacute;mulo e a libera&ccedil;&atilde;o de macronutrientes da biomassa seca, da braqui&aacute;ria (<em>Brachiaria brizantha</em>) e do capim momba&ccedil;a (<em>Panicum maximum</em>), utilizados como cobertura de solo, no sistema plantio direto, em condi&ccedil;&otilde;es da regi&atilde;o do Cerrado. O experimento foi conduzido na Embrapa Arroz e Feij&atilde;o (Fazenda Capivara), em Santo Ant&ocirc;nio de Goi&aacute;s, GO, em Latossolo Vermelho distr&oacute;fico. O delineamento experimental foi de blocos ao acaso, com quatro repeti&ccedil;&otilde;es, em esquema de parcelas subdivididas no tempo. Na fase de florescimento, as plantas foram cortadas e mantidas sobre o solo, sendo avaliados a produtividade da biomassa seca, ac&uacute;mulo de nutrientes e a decomposi&ccedil;&atilde;o e libera&ccedil;&atilde;o destes, no per&iacute;odo de 0, 15, 30, 45, 60 e 75 dias. O capim braqui&aacute;ria apresentou produtividade de biomassa de 16.643 kg ha<sup>-1</sup> e o momba&ccedil;a de 18.244 kg ha<sup>-1</sup>. O N foi o nutriente de maior ac&uacute;mulo nas duas plantas de cobertura. Dentre os macronutrientes analisados, o K apresentou a maior taxa de libera&ccedil;&atilde;o (70% e 59%, respectivamente, para o momba&ccedil;a e braqui&aacute;ria).</span></span></span></p> <p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="pt-BR" align="JUSTIFY"><span style="color: #000000;"><span><span style="font-size: small;">PALAVRAS-CHAVE: <em>Brachiaria brizantha</em>;<em> Panicum maximum</em>; taxa de decomposi&ccedil;&atilde;o; acumula&ccedil;&atilde;o de macronutriente; semeadura direta.</span></span></span></p>

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