Paulo Sérgio Rabello de Oliveira

Valor nutricional e características estruturais de gramíneas tropicais sob adubação nitrogenada

EnglishThe experiment was carried out in the expe- rimental farm of Unioeste, Marechal Candido Rondon, PR, Brasil, with the objective of evaluate the effects of increasing N doses under structural features and chemical composition of three tropi- cal forage grasses. The experimental design used was of randomized blocks in factorial scheme 3x4, with three tropical forages (Panicum maximum cvs. tanzânia and mombaca, and Brachiaria sp. cv. mulato) and four doses of N (0; 40; 80 and 160 kg/ha) taking urea as N sources. Were evaluated: canopy height leaf/stem ratio, diameter and height of pseudoculm, and contents of crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and mineral matter (MM). There was effect of N doses on canopy height and height of pseudoculm that showed quadratic behavior. The leaf/stem ratio responded negatively to N doses, while the diameter of pseudoculm was influenced only by forages. For CP content was found significance of interaction of factors, being that in dose of 80 kg/ha of N the Tanzania grass was higher than the other. The contents of NDF responded of form quadratic to N doses, while the contents of ADF were influenced only by forages. portuguesO experimento foi conduzido na Fazenda Ex- perimental da Unioeste, Marechal Cândido Rondon, PR, Brasil, com o objetivo de avaliar os efeitos de doses crescentes de N sobre caracteristicas estruturais e composicao quimica de tres gramineas forrageiras tropicais. O delineamento experimen- tal utilizado foi o em blocos casualizados em es- quema fatorial 3 x 4, com tres forrageiras tropicais (Panicum maximum cvs. tanzânia e mombaca, e Brachiaria sp. cv. mulato) e quatro doses de N (0; 40; 80 e 160 kg/ha) tendo como fonte a ureia. Foram avaliados: a altura do dossel, a relacao folha/colmo, a proporcao de folhas e de colmos na forragem produzida, o diâmetro e a altura do pseudocolmo, e os teores de proteina bruta (PB), fibra em detergente neutro (FDN), fibra em deter- gente acido (FDA) e materia mineral (MM). Houve efeito das doses de N sobre a altura do dossel e sobre a altura do pseudocolmo, que apresentaram comportamento quadratico. A relacao folha/colmo respondeu de forma negativa as doses de N, enquanto o diâmetro do pseudocolmo foi influen- ciado apenas pelas forrageiras. Para o teor de PB foi constatada significância da interacao dos fatores, de forma que na dose de 80 kg/ha de N o capim tanzânia foi superior aos demais. Os teores de FDN responderam de forma quadratica as doses de N, enquanto os teores de FDA foram influenciados apenas pelas forrageiras.

Características produtivas, estruturais e bromatológicas dos capins Tifton 85 e Piatã e do feijão-guandu cv. Super N, em cultivo singular ou em associação

This trial aimed at evaluating characteristics as: production, structural and nutritional requirements of Tifton 85 and Piata grasses and pigeonpea in single or intercropped tillage, with and without nitrogen application. The experimental plot in randomized blocks with plots subdivided through time, with 7 treatments in the main plots and three periods of evaluation on subplots with four replications. The studied treatments were: Cajanus cajan cv. Super N (pigeonpea), Brachiaria brizantha cv. single Piata without application of nitrogen (N); B. brizantha cv. Piata in association with pigeonpea; B. brizantha cv. single Piata with application of N (150kg ha-1); Cynodon sp. Tifton 85 in a single crop without application of N; Tifton 85 in association with pigeonpea and Tifton 85 plus an application of N (150kg ha-1) and three cycles of evaluations. The association of Tifton 85 and Piata grasses with pigeonpea provided forage production like nitrogen fertilizer and increase crude protein content and a reduction on neutral detergent fiber contents. Tifton grass was less tolerant to shading from pigeonpea.

Production of tifton 85 hay overseeded with white oats or ryegrass

The objective of this experiment was to estimate the curve of dehydration, chemical composition and in vitro dry matter digestibility (IVDMD) and crude protein digestibility (IVCPD) of tifton 85 hay, produced single or overseeded with ryegrass or white oat IPR 126. The experimental design was in randomized blocks, in a 3 × 10 factorial arrangement, with three cropping systems and ten evaluation times (0, 4, 8, 24, 28, 32, 48, 52 and 56 and 71 hours after harvest) during the dehydration process. For chemical composition and in vitro DM and CP digestibility, the experimental design was in randomized blocks with three cropping systems and three evaluation times (before cutting, before baling and 100 days after of storage). It was found that tifton 85 intercropped with white oat kept its higher nutritional value after storage, with 19.78% crude protein and 70.03% of in vitro dry matter digestibility. The participation of white oat in tifton 85 area was 57.04% and for ryegrass, it was 38.52%, but the dry matter yield of single tifton 85 was higher than other intercrops. Thus, it is recommended an oversowing of winter annual species on Tifton 85, without moisture restriction, because of the benefits obtained in the hay nutritional value.

Produção de forragem, características estruturais e eficiência de utilização do nitrogênio em forrageiras tropicais sob adubação nitrogenada

This study aimed to evaluate the effects of increasing doses of nitrogen on the morphogenesis, structural and productive grass Panicum maximum cvs. Mombaca and Tanzania, and Brachiaria sp. Mulato. The experiment was conducted under field conditions. The experimental design was randomized blocks in a 3x4 factorial design with three forages ( Panicum maximum cvs. Tanzania and Mombaca and Brachiaria sp. cv. Mulato), four N rates (0, 40, 80 and 160 kg ha-1) with three replications. Were evaluated the following parameters: fresh matter production (FMP), dry matter production (DMP), plant height, percentage of dry matter, leaves per tiller, dry matter accumulation rate (DMAR) and nitrogen use efficiency (NUE). Grasses Mombasa and Tanzania showed similar results, and both were superior to Mulato grass for the production of fresh and dry matter. The three species responded to nitrogen application, with an increase in FMP, DMP, DMAR, height and number of tillers. The maximum efficiency in use of N was obtained with a dose of 120 kg ha-1.

Produção e composição químico-bromatológica da aveia preta fertilizada com doses crescentes de dejeto líquido suíno

O trabalho teve como objetivo avaliar o efeito da aplicacao de doses crescentes de dejeto liquido suino sobre a producao e composicao quimico-bromatologica da parte aerea da aveia preta. O experimento foi conduzido em sistema de plantio direto sob o delineamento em blocos casualizados com quatro repeticoes e os tratamentos constituidos pela aplicacao de 0; 10; 20; 30; 40 e 50 m3 ha-1 de dejeto liquido suino. Foram determinados a producao de MS da parte aerea, a relacao folha:colmo e os teores de proteina bruta (PB), fibra em detergente acido (FDA), fibra em detergente neutro (FDN), materia mineral (MM), materia orgânica (MO), nitrogenio (N), fosforo (P), potassio (K), calcio (Ca), magnesio (Mg), cobre (Cu), zinco (Zn), manganes (Mn) e ferro (Fe). A aplicacao de dejeto liquido suino nao promoveu efeitos significativos sobre a producao de MS e teores de FDN, MM e MO, mas promoveu aumento linear da relacao folha:colmo e do teor de PB e reducao linear no teor de FDA. Quanto aos minerais, as doses de dejeto liquido suino promoveram aumento linear nos teores de N, P, K, Ca e Zn, sem efeitos sobre os demais minerais estudados. A utilizacao de dejeto liquido suino na fertilizacao da cultura da aveia ate a dose de 50 m3 ha-1 nao aumenta a producao de forragem mas eleva o valor nutricional.

Crescimento de Stylosanthes cv. Campo Grande em diferentes níveis de densidade de um Latossolo Vermelho

O Stylosanthes spp. cv. Campo Grande e uma leguminosa recomendada para a recuperacao de areas de pastagens degradadas, entretanto sao escassas as informacoes sobre seu desenvolvimento em solos compactados. Assim, objetivou-se com o presente trabalho avaliar o desenvolvimento do Stylosanthes cv. Campo Grande em diferentes niveis de densidade de um Latossolo Vermelho eutroferrico (LVef). O experimento foi desenvolvido no periodo entre setembro de 2007 e marco de 2008, em cultivo protegido. O delineamento experimental utilizado foi inteiramente casualizado. Os tratamentos consistiram de cinco niveis de compactacao do solo em sub-superficie (1,0; 1,2; 1,4; 1,6 e 1,8 Mg m-3) com quatro repeticoes. As unidades experimentais foram compostas por vasos montados a partir de aneis de PVC sobrepostos. No solo estudado (LVef) o maximo crescimento do Stylosanthes cv. Campo Grande ocorre com a densidade de solo em torno de 1,27 Mg m-3; e densidades de solo acima de 1,00 Mg m-3 limitam o desenvolvimento radicular desta leguminosa.

Produção de biomassa de cultivares de aveia sob diferentes manejos de corte

In the crop -livestock integration system , improper oat management can result in low biomass yield. This study aimed to evaluate the effect of cutting management systems on the biomass yield of five oat cultivars with potential use in the crop-livestock integration system. A completely randomized blocks design with four replications, in a split-plot scheme, was used. The plots were represented by the oat cultivars Preta Comum, IAPAR 61, IPR 126, FAPA 2, and FUNDACEP FAPA 43. The Preta Comum cultivar features a short cycle, while the others have a long one . The sub-plots were represented by the following cutting systems: one single cut in the flowering stage, one cut in the vegetative and other in the flowering stage, two cuts in the vegetative and other in the flowering stage, and three cuts in the vegetative and other in the flowering stage. The long cycle cultivars (IAPAR 61, IPR 126, FAPA 2, and FUNDACEP FAPA 43) reached high forage yield, without affecting the subsequent fodder yield for soil covering, pointing out its ability to be used in crop-livestock systems. The management systems with three cuts in the vegetative stage maximizes the forage yield, however, concerning fodder yield, the best results were obtained by using up to two cuts in the vegetative stage, or a single one in the flowering stage.

IPR 126 white oat forage potential under free growth, cutting and grazing at two management heights

The experiment was carried out to evaluate the structural characteristics, biomass accumulation, chemical composition and in vitro digestibility of dry matter and crude protein of white oat (Avena sativa L. IPR 126) under different management systems. Grazing, cut at two heights (15 and 20 cm) and free growth were all evaluated in three periods (July, August and September) with a 28-day average interval between evaluations. In the free growth system, samples at 15 and 20 cm were also taken at the intervals chosen for cutting and grazing. The experimental design was in randomized blocks with three replications, arranged in a 3 × 2 factorial split plot design over time; systems of management and heights were the factors of plots, and time was taken as subplot. There was higher straw production under free growth, but, with decreased chemical quality from the first to the second period and from the second to the third one, with 236.4, 172.5, and 91.4 g/kg crude protein values, respectively. Regarding cutting and grazing systems, they showed structural changes in tillering, which was favored by the cut, but with some reduction in the periods. Nutritional quality values were close to cutting and grazing with high crude protein content (216.6 g/kg), adequate neutral detergent fiber (535.4 g/kg) content and high in vitro digestibility of dry matter (826.3 g/kg). Management heights promoted few changes in the characteristics evaluated. After the third period, cutting and grazing systems showed no suitable residual straw for ground covering and set a summer crop under no-tillage system, with 738.39 kg/ha of residual dry matter on average.

Use of conditioners in the production of Tifton 85 grass hay

ABSTRACT - The objectives of this study were to estimate the curve of dehydration, bromatological compositionand occurrence of fungi in Tifton 85 grass, submitted to four methods of dehydration. The curves of dehydration werestudied in a completely randomized design with a 4 × 11 factorial scheme with four drying systems (1 conditioning + 1turn-over; 2 conditionings + 1 turn-over; no conditioning + 1 turn-over and no conditioning + 2 turn-overs) and 11sampling times (0, 3, 15, 18, 21, 24, 39, 42, 45 and 47 hours after the cutting), with six replicates. For the bromatologicalcomposition and fungi occurrence, the experimental design was completely randomized in a 4 × 3 factorial scheme withthe four drying methods of Tifton 85 grass and three periods of evaluation (before the cutting, at the time of the balingand 30 days after storage) with six replicates. It was found that after the first hour after cutting and at the end of theperiod of dehydration, Tifton 85 plants that were treated with conditioners showed higher levels of dry matter. Storedhay that was treated with conditioners presented higher levels of acid detergent insoluble protein. Until baling, the dryingmethods did not alter the crude protein content of hay; however, after storage, the hay submitted only to turn-over showedcrude protein content higher (13.90%) than those submitted to conditioners (9.94%). There was an increase in theoccurrence of fungi after storage, but the application of conditioners and one turn-over resulted in lower CUF/g, comparedwith other treatments, enhancing the effect of conditioners on accelerating the dehydration rate and obtaining betterhay storage conditions.Key Words: conservation, crude protein, dehydration, storage fungus

Use of a conditioning unit at the haymaking of Tifton 85 overseeded with Avena sativa or Lolium multiflorum

White oat and ryegrass were overseeded on Tifton 85 pastures for evaluation of dry matter yield (DMY), leaf:stem ratio (L:S), dehydration curves and nutritional value of forages. Dry matter intake and L:S ratio were analyzed using a completely randomized blocks design with five forage growth conditions (single Tifton 85 and intercropped with white oat or ryegrass, and white oat or ryegrass intercropped with Tifton 85), whereas for drying curves, ten dehydration times were tested (0, 4, 8, 24, 28, 32, 48, 52, 56 and 71 hours after harvest) by a 5 × 10 split-plot arrangement (growth conditions of forages as main plot and dehydration times as sub-plots). The nutritive value data were analyzed in a 3 × 3 split-plot trial with single Tifton 85, Tifton 85 - Oat and Tifton 85-Ryegrass as main plots and the three sampling times (before harvesting, at baling and 100 days after storage) as sub-plots. Oat and ryegrass showed higher L:S ratio, while the intercrops of Tifton 85 - Oat and Tifton 85 - Ryegrass presented lower DMY, but higher crude protein concentration and in vitro DM digestibility than single Tifton. Neutral and acid detergent fiber concentrations were higher for single Tifton 85. Ryegrass and white oat, overseeded on Tifton 85 pasture, improved the nutritional value of the hay produced; however, in a 100-day storage period, there was a reduction in in vitro dry matter digestibility and crude protein concentrations.