RESUMO

The objective of our study was to evaluate the effect of the use of legume (Arachis pintoi) or nitrogen fertilization on animal performance, characteristics of carcass and meat, and fatty acids profile of crossbred steers on Megathyrsus maximus cv. Aruana pasture, overseeded with temperate grasses. The experimental design was completely randomized, with three treatments and three replicates. The experiment was carried out from June to October (127 d). The treatments were: Low-N: 100 kg of N/ha; Medium-N: 200 kg of N/ha; and Legume: Arachis pintoi + 100 kg of N/ha. The pasture with higher nitrogen fertilization (N200) showed a more significant forage mass yield. The mixed grass with legumes presented a higher concentration of saturated fatty acids and saturated:unsaturated ratio in the meat. However, the grass pastures resulted in a higher content of unsaturated fatty acids in the meat. The other pasture variables, and characteristics of carcass and meat were not influenced by the treatments. The increase in nitrogen fertilization, from 100 to 200 kg/ha, and Arachis pintoi mixed with Aruana grass pasture overseeded with black oat and ryegrass does not affect the daily weight gain and the carcass and meat characteristics of the steers. The grass-legume mixture decreases the total concentration of unsaturated fatty acids in meat without influencing the concentration of polyunsaturated fatty acids.(AU)

Assuntos

RESUMO

Integrating warm-climate forage legumes into grass monocultures has received significant research attention during the past 70 years, but widespread adoption by end users has been elusive. The objectives of this review are to provide historical context regarding legume use in warm-climate grasslands; synthesize the current literature addressing contributions to grassland ecosystem services of warm-climate, grass-only vs. legume-grass mixed swards; and consider how to achieve more widespread adoption of legume technology in warm climates. For this review, warm-climate grasslands are considered those in areas between latitudes 30° N and 30° S, where C4 perennial grasses dominate. The literature suggests measurable advantages in animal performance, soil carbon accumulation, and nutrient cycling of legume-grass mixtures are most likely when grass-only swards receive little or no N fertilizer. Advantages are less or may disappear when mixtures are compared with grasses receiving high N fertilizer rates. In contrast, amelioration of greenhouse gas emissions is often most pronounced for mixtures when compared with grass-only swards receiving high rates of N, because of the magnitude of N fertilizer effects on emissions. Going forward, there is need to focus on selecting for, and thoroughly documenting legume persistence, achieving low-risk and affordable legume establishment methods, assessing compatibility of legumes in mixture with grasses prior to legume cultivar release, emphasizing adoption of both legume species and optimal management practices, and recognizing scientists must assume a larger and more intentional role in encouraging adoption by end-users of research innovations, in addition to our traditional role in technology and product development.(AU)

Assuntos

RESUMO

Maintenance of mixed grass-legume pastures for stand longevity and improved animal utilization is a challenge in warm-season climates. The goal of this study was to assess grazing management on stand persistence, forage intake, and N balance of beef heifers grazing mixed pastures of Brachiaria brizantha and Arachis pintoi. A 2-yr experiment was carried out in Brazil, where four grazing management were assessed: rest period interrupted at 90%, 95%, and 100% of light interception (LI) and a fixed rest period of 42 d (90LI, 95LI, 100LI, and 42D, respectively). The LI were taken at 50 points at ground level and at 5 points above the canopy for each paddock using a canopy analyzer. For all treatments, the postgrazing stubble height was 15 cm. Botanical composition and canopy structure characteristics such as canopy height, forage mass, and vertical distribution of the morphological composition were evaluated pre- and post-grazing. Forage chemical composition, intake, and microbial synthesis were also determined. A randomized complete block design was used, considering the season of the year as a repeated measure over time. Grazing management and season were considered fixed, while block and year were considered random effects. In the summer, legume mass accounted for 19% of the canopy at 100LI, which was less than other treatments (a mean of 30%). The 100LI treatment had a greater grass stem mass compared with other treatments. In terms of vertical distribution for 100LI, 38.6% of the stem mass was above the stubble height, greater than the 5.7% for other treatments. The canopy structure limited NDF intake (P = 0.007) at 100LI (1.02% of BW/d), whereas 42D, 90LI, and 95LI treatments had NDF intake close to 1.2% of BW/d. The intake of digestible OM (P = 0.007) and the ratio of CP/digestible OM (P < 0.001) were less at 100LI in relation to the other treatments. The production of microbial N (P < 0.001) and efficiency of microbial synthesis (P = 0.023) were greater at 95LI and 90LI, followed by 42D and less at 100LI. Overall, the range from 90% to 95% of LI is the recommendation to interrupt the rest period, since this strategy enhanced community stability, forage intake, and nutritional value of the diet. Under on-farm conditions, brachiaria grass and forage peanut pastures should be managed at a range height of 24 to 30 cm.

Assuntos

RESUMO

The effect of level of P, K, B,Cu and Zn was measured in a small plot experiment with jaragua grass plus perenial soybean pasture. The experimental design was a randomized block with two replications. where the treatments were combined in an incomplete factorial using a modified central composite design. At seeding time, it was used a diferential fertilization, applying only 20kg of P2O5/ha in the rows of the grass. While, in the rows of the the legume P, K, B, Cu and Zn fertilizations were applied according to the level combinations. In the mixture, the legume. and the grass+ legume yields were increased up to the aplication of about 70kg of K2O/ha after each harvest, and linearly with the levels of phosphorous applied at the seeding time. Grass yield decreased linearly as phosphorus levels increased in the legume row, showing that as the establishment speed of the legume is stimulated by P fertilization the one of the grass, fertlized with a low level of P in its lines, is impaired.

O experimento foi conduzido em parcelas, objetivando estudar o efeito de doses de P, K e micronutrientes (B, Cu e Zn) na consorciação do capim-jaraguá (Hyparrhenia rufa (Nees) Stapf.) e soja-perene (Neonotonia wightii Lanckey cv. Tinaroo). O delineamento experimental foi o de blocos ao acaso, em esquema fatorial incompleto, arranjado segundo o método do ponto central modificado, com duas repetições. Na semeadura utilizou-se adubação diferenciada, aplicando-se 20kg de P2O5 por hectare nas linhas do jaraguá. Nas linhas da leguminosa, foram aplicados fósforo, potássio e micronutrientes em diferentes doses. Como efeito médio dos quatro anos experimentais, as doses de P resultaram em aumentos lineares nas quantidades de matéria seca e nos teores de proteína bruta da soja-perene e da mistura e nos teores de nitrogênio e fósforo da leguminosa. Ao mesmo tempo reduziram linearmente a quantidade de matéria seca e de proteína bruta do capim-jaraguá e os teores de magénsio e boro da leguminosa. Os teores de K da soja-perene elevaram-se até a dose de 96kg de P2O5/ha. As doses de potássio incrementaram linearmente a quantidade de proteína bruta da leguminosa e da mistura, e aumentaram o teor de N da soja-perene, reduzindo seus teores de Ca, Mg e B. As produções de matéria seca da soja-perene e da mistura aumentaram até a dose de 70kg de K2O/há e os teores de K na leguminosa até 111kg de K2O/

RESUMO

The effect of level of P, K, B,Cu and Zn was measured in a small plot experiment with jaragua grass plus perenial soybean pasture. The experimental design was a randomized block with two replications. where the treatments were combined in an incomplete factorial using a modified central composite design. At seeding time, it was used a diferential fertilization, applying only 20kg of P2O5/ha in the rows of the grass. While, in the rows of the the legume P, K, B, Cu and Zn fertilizations were applied according to the level combinations. In the mixture, the legume. and the grass+ legume yields were increased up to the aplication of about 70kg of K2O/ha after each harvest, and linearly with the levels of phosphorous applied at the seeding time. Grass yield decreased linearly as phosphorus levels increased in the legume row, showing that as the establishment speed of the legume is stimulated by P fertilization the one of the grass, fertlized with a low level of P in its lines, is impaired.

O experimento foi conduzido em parcelas, objetivando estudar o efeito de doses de P, K e micronutrientes (B, Cu e Zn) na consorciação do capim-jaraguá (Hyparrhenia rufa (Nees) Stapf.) e soja-perene (Neonotonia wightii Lanckey cv. Tinaroo). O delineamento experimental foi o de blocos ao acaso, em esquema fatorial incompleto, arranjado segundo o método do ponto central modificado, com duas repetições. Na semeadura utilizou-se adubação diferenciada, aplicando-se 20kg de P2O5 por hectare nas linhas do jaraguá. Nas linhas da leguminosa, foram aplicados fósforo, potássio e micronutrientes em diferentes doses. Como efeito médio dos quatro anos experimentais, as doses de P resultaram em aumentos lineares nas quantidades de matéria seca e nos teores de proteína bruta da soja-perene e da mistura e nos teores de nitrogênio e fósforo da leguminosa. Ao mesmo tempo reduziram linearmente a quantidade de matéria seca e de proteína bruta do capim-jaraguá e os teores de magénsio e boro da leguminosa. Os teores de K da soja-perene elevaram-se até a dose de 96kg de P2O5/ha. As doses de potássio incrementaram linearmente a quantidade de proteína bruta da leguminosa e da mistura, e aumentaram o teor de N da soja-perene, reduzindo seus teores de Ca, Mg e B. As produções de matéria seca da soja-perene e da mistura aumentaram até a dose de 70kg de K2O/há e os teores de K na leguminosa até 111kg de K2O/

RESUMO

A field experiment to study the effects of phosphorus and gypsum sources in a mixed pasture was carried out at the Animal Husbandry Experimental Station located in Colina, State of São Paulo, Brazil. The pasture had pangolagrass mixed with siratro, perennial soybean and centro. The soil was a Dark Red Latosol (Oxisol). A factorial experiment was used, with phosphorus sources x gypsum (5x2), with the ten treatments assigned in a randomized complete block design, with four replications. Phosphorus sources were: no phosphorus fertilization (Control), triple superphosphate (44% P2O5), Araxa rock phosphate (28% P2O5), Alvorada rock phosphate (28% P2O5), and Patos rock phosphate (18% P2O5). Gypsum was the by product of the fertilizer industry and contained 15% S. Thirteen harvests were done in the four years of experimentation. The results evidenced that: a) triple superphosphate had a beneficial effect on the legumes dry matter yield m the first year whereas the other sources had such effect on the fourth year; b) gypsum application significantly increased S percentage in the legumes (first year), proportion of the legumes in the pasture (second year), and legumes dry matter yield (fourth year); c) phosphate application significantly increased P percentage in the grass in all experimental years; d) legumes proportion in the pasture was higher in phosphate fertilized plots than in th

Em experimento instalado numa pastagem consorciada de capim-pangola com siratro, soja-perene e centrosema, formada há cerca de 4 anos, em um Latossolo Vermelho-Escuro fase arenosa (LEa) da Estação Experimental de Zootecnia de Colina, estudaram-se os efeitos de fontes de fósforo e do gesso sobre produção e teores de nutrientes nas forrageiras. Utilizou-se um fatorial 5x2 (fontes de fósforo x gesso), com dez tratamentos dispostos em blocos ao acaso, com quatro repetições. As fontes de fósforo foram: sem adubação fosfatada (testemunha), superfosfato triplo, fosfato de Araxá, fosfato de Alvorada e fosfato de Patos. Foram realizados 13 cortes de avaliação, durante quatro anos. Os resultados mostraram que: a) há um efeito significativo do superfosfato triplo sobre a produção de matéria seca das leguminosas no primeiro ano e das demais fontes de fósforo no quarto ano; b) o gesso promove aumento significativo do teor de enxofre nas leguminosas no primeiro ano, aumento da porcentagem de leguminosas na mistura no segundo ano, bem como aumento nas suas produções no quarto ano; c) ocorrem aumentos significativos do teor de fósforo na gramínea, em todos os quatro anos, pela aplicação dos adubos fosfatados; d) a partir do segundo ano a porcentagem de leguminosas na mistura, nos tratamentos com aplicação de fósforo é maior que na testemunha.

RESUMO

A field experiment to study the effects of phosphorus and gypsum sources in a mixed pasture was carried out at the Animal Husbandry Experimental Station located in Colina, State of São Paulo, Brazil. The pasture had pangolagrass mixed with siratro, perennial soybean and centro. The soil was a Dark Red Latosol (Oxisol). A factorial experiment was used, with phosphorus sources x gypsum (5x2), with the ten treatments assigned in a randomized complete block design, with four replications. Phosphorus sources were: no phosphorus fertilization (Control), triple superphosphate (44% P2O5), Araxa rock phosphate (28% P2O5), Alvorada rock phosphate (28% P2O5), and Patos rock phosphate (18% P2O5). Gypsum was the by product of the fertilizer industry and contained 15% S. Thirteen harvests were done in the four years of experimentation. The results evidenced that: a) triple superphosphate had a beneficial effect on the legumes dry matter yield m the first year whereas the other sources had such effect on the fourth year; b) gypsum application significantly increased S percentage in the legumes (first year), proportion of the legumes in the pasture (second year), and legumes dry matter yield (fourth year); c) phosphate application significantly increased P percentage in the grass in all experimental years; d) legumes proportion in the pasture was higher in phosphate fertilized plots than in th

Em experimento instalado numa pastagem consorciada de capim-pangola com siratro, soja-perene e centrosema, formada há cerca de 4 anos, em um Latossolo Vermelho-Escuro fase arenosa (LEa) da Estação Experimental de Zootecnia de Colina, estudaram-se os efeitos de fontes de fósforo e do gesso sobre produção e teores de nutrientes nas forrageiras. Utilizou-se um fatorial 5x2 (fontes de fósforo x gesso), com dez tratamentos dispostos em blocos ao acaso, com quatro repetições. As fontes de fósforo foram: sem adubação fosfatada (testemunha), superfosfato triplo, fosfato de Araxá, fosfato de Alvorada e fosfato de Patos. Foram realizados 13 cortes de avaliação, durante quatro anos. Os resultados mostraram que: a) há um efeito significativo do superfosfato triplo sobre a produção de matéria seca das leguminosas no primeiro ano e das demais fontes de fósforo no quarto ano; b) o gesso promove aumento significativo do teor de enxofre nas leguminosas no primeiro ano, aumento da porcentagem de leguminosas na mistura no segundo ano, bem como aumento nas suas produções no quarto ano; c) ocorrem aumentos significativos do teor de fósforo na gramínea, em todos os quatro anos, pela aplicação dos adubos fosfatados; d) a partir do segundo ano a porcentagem de leguminosas na mistura, nos tratamentos com aplicação de fósforo é maior que na testemunha.

RESUMO

This field experiment studied the effect of levels of P, K, and Mo in a mixed guineagrass plus siratro pasture. The experimental design was in Complete Randomized Block with two replications and the treatments were combined in a incomplete factorial using a modified central composite design. At seeding time it was used a diferential fertilization, applying only 20 kg of P205/ha in the rows of the grass and, in the rows of the legume the P, K and Mo fertilizations were according to the level combinations. The grass was also studied as single culture, fertilized with levels of N. In the mixture, the grass, the legume and the grass + legume yields were increased with the application of about 120 kg of P205/ha and 70 kg K/ha, being the response to Mo different for each component and equal to the application of 196, 274, and 225 g of molybdemum per ha. No limiting siratro productions occurred when the soil K was arround 60 ppm and the forrage K concentrations were 1,40% in the dry matter (65C) which correspondend to an applicaction of 50 kg K2O/ha harvest. Considering a four year mean the dry matter yield of the mixture was equivalent to a fertilization of 120 kg N/ha in the grass alone.

O experimento foi conduzido em parcelas, objetivando estudar o efeito de níveis de P, K e Mo na consorciação do capim-colonião e siratro. O delineamento experimental foi de blocos completos ao acaso, com esquema fatorial incompleto, sendo os tratamentos arranjados segundo o método do ponto central modificado, com duas repetições. Na semeadura utilizou-se adubação diferenciada, aplicando-se 20 kg de P2O5/ha nas linhas de colonião e, nas linhas da leguminosa, adubação fosfatada, potássica e com molibdênio em diferentes níveis conforme o tratamento. Estudou-se também, o efeito de níveis de N na gramínea exclusiva, com vistas a determinar-se a equivalência da leguminosa com esse tipo de adubação. A gramínea, a leguminosa e a mistura, tiveram suas produções de matéria seca aumentadas com a aplicação de até cerca de 120 kg de P2O5/ha, e de 70 kg de K2O/ha, sendo a resposta ao Mo diferenciada e respectivamente até 196, 274 e 225 de molibdênio por hectare, O nível de K, adequado á produção eficaz do siratro, foi em torno de 60 ppm de K no solo e de 1,40% de K na matéria seca-a 65C da planta, correspondendo a uma aplicação de cerca de 50 kg de K2O/ha/corte.Considerando-se a média de 4 anos, a produção de matéria seca da mistura correspondeu a uma adubação com cerca de 120 kg de N por hectare na gramínea exclusiva.

RESUMO

This field experiment studied the effect of levels of P, K, and Mo in a mixed guineagrass plus siratro pasture. The experimental design was in Complete Randomized Block with two replications and the treatments were combined in a incomplete factorial using a modified central composite design. At seeding time it was used a diferential fertilization, applying only 20 kg of P205/ha in the rows of the grass and, in the rows of the legume the P, K and Mo fertilizations were according to the level combinations. The grass was also studied as single culture, fertilized with levels of N. In the mixture, the grass, the legume and the grass + legume yields were increased with the application of about 120 kg of P205/ha and 70 kg K/ha, being the response to Mo different for each component and equal to the application of 196, 274, and 225 g of molybdemum per ha. No limiting siratro productions occurred when the soil K was arround 60 ppm and the forrage K concentrations were 1,40% in the dry matter (65C) which correspondend to an applicaction of 50 kg K2O/ha harvest. Considering a four year mean the dry matter yield of the mixture was equivalent to a fertilization of 120 kg N/ha in the grass alone.

O experimento foi conduzido em parcelas, objetivando estudar o efeito de níveis de P, K e Mo na consorciação do capim-colonião e siratro. O delineamento experimental foi de blocos completos ao acaso, com esquema fatorial incompleto, sendo os tratamentos arranjados segundo o método do ponto central modificado, com duas repetições. Na semeadura utilizou-se adubação diferenciada, aplicando-se 20 kg de P2O5/ha nas linhas de colonião e, nas linhas da leguminosa, adubação fosfatada, potássica e com molibdênio em diferentes níveis conforme o tratamento. Estudou-se também, o efeito de níveis de N na gramínea exclusiva, com vistas a determinar-se a equivalência da leguminosa com esse tipo de adubação. A gramínea, a leguminosa e a mistura, tiveram suas produções de matéria seca aumentadas com a aplicação de até cerca de 120 kg de P2O5/ha, e de 70 kg de K2O/ha, sendo a resposta ao Mo diferenciada e respectivamente até 196, 274 e 225 de molibdênio por hectare, O nível de K, adequado á produção eficaz do siratro, foi em torno de 60 ppm de K no solo e de 1,40% de K na matéria seca-a 65C da planta, correspondendo a uma aplicação de cerca de 50 kg de K2O/ha/corte.Considerando-se a média de 4 anos, a produção de matéria seca da mistura correspondeu a uma adubação com cerca de 120 kg de N por hectare na gramínea exclusiva.