Flávio Henrique Silveira Rabêlo

Perdas fermentativas e estabilidade aeróbia de silagens de cana-de-açúcar tratadas com cal virgem e cloreto de sódio

Esta pesquisa foi realizada com o objetivo de determinar o efeito da inclusao de cal virgem e cloreto de sodio sobre as perdas fermentativas e a estabilidade aerobia de silagens de cana-de-acucar. O delineamento experimental utilizado foi o totalmente ao acaso em esquema de parcelas subdivididas com quatro repeticoes, de modo que os aditivos foram avaliados nas parcelas (silagem sem aditivo; silagens contendo 0,5; 1,0 e 2,0% de cloreto de sodio; e silagens contendo 0,5; 1,0 e 1,5% de cal virgem na materia natural) e os tempos de exposicao ao oxigenio nas subparcelas. Apos 75 dias da ensilagem, os silos foram abertos para determinacao dos teores de materia seca (MS) e da perda de MS por efluente e gases e afericao da temperatura e do pH da silagem. A inclusao de cal nas silagens, independentemente da dose utilizada, proporcionou maior teor de MS e menor perda de MS. As menores temperaturas foram observadas nas silagens tratadas com cloreto de sodio. Os aditivos utilizados, sobretudo o cloreto de sodio, foram eficientes em manter a estabilidade aerobia da silagem de cana.

Perdas fermentativas e estabilidade aeróbia de silagens de milho inoculadas com bactérias ácido-láticas em diferentes estádios de maturidade

The aim of this work was to evaluate the inoculation of lactic acid bacterial in corn silages produced in different development stages on the fermentative losses and aerobic stability. The experimental design was completely randomized in factorial scheme 3x5 evaluating two commercial inoculants (Silobac® and Maize All®) and a control treatment (silage untreated) in five maturity stages with four replicates. The application of Silobac® and Maize All® decreased the dry matter losses during the fermentative process in 1.78 and 1.75 percentage points when compared to control silage (7.95%). The silages produced with 2/3 of milk line and black layer presented lower dry matter losses due mainly to the lower effluent production. The higher aerobic stability was observed in a silage produced with corn plants in the black layer stage and inoculated with Maize All®, where there was lower aerobic stability than other silages inoculated with the same product due to increase of moisture of the silages. The inoculants used in this work are efficient in decrease the dry matter losses during the fermentative process, however, there is higher concentration of nutrients in this silages resulting in lower stability after the opening of the silos. Silages produced with higher dry matter content present higher dry matter losses, as well as more stability during the aerobic exposure.

Composição química e digestibilidade in vitro da massa seca de cana-de-açúcar acrescida de ureia em diferentes tempos de estocagem

The objective of this research was to evaluate the chemical composition and in vitro dry mass (DM) digestibility of sugar cane with urea, maintained in the shade and sun, at different storage times. The utilized design was the completely randomized in a factorial scheme 6x2, that is, six storage times after the mixing (0; 2; 4; 6; 12 and 24 hours) and two storage location (shade and sun), with three replicates. The sugarcane utilized presented 12 months of development and was disintegrated for application of mixture (nine parts of urea for one of ammonium sulfate) to 1.0kg/100.0kg of fresh sugarcane. The samples taken with 12 hours of storage indicated that was an increase in the content of DM and crude protein (CP) of sugar cane compared to the moment of the mixture (307.6 vs. 294.2g/kg of DM and 115.2 vs. 99.3 g/kg of DM, respectively), and the smaller content of neutral detergent fiber (NDF) was observed around of 12 hours of storage (465.0g/kg of DM). The coefficients of in vitro dry mass digestibility (IVDMD) ranged of 0.558 to 0.612 in the times 0 and 12 hours, respectively. The length of storage changes the chemical composition of sugar cane plus urea. The storage location changes the dry mass content and pH values.

ALTERAÇÕES NOS ATRIBUTOS QUÍMICOS DO SOLO PELO USO E MANEJO EM LATOSSOLO NA AMAZÔNIA

The proper soil use and management are essential for a sustainable production, thus the pursuit for systems that minimize damages to the environment and improve soil fertility is continuous. The objective of this study was to evaluate changes in soil fertility by the use and management of an Oxisol (Latossolo Vermelho-amarelo, SiBCS) in the Amazon biome. The soil uses and management systems evaluated were native forest, native pasture, minimum tillage system and conventional tillage system. The chemical atributes of the soil layers 0.00-0.10, 0.10-0.20, 0.20-0.30 and 0.30-0.40 m were evaluated. The soil pH (CaCl2) and the contents of organic matter, available phosphorus and exchangeable potassium, calcium, magnesium and aluminum were evaluated and the saturation by Al, effective cation exchange capacity and soil potential were determined. The highest pH values were found in the native pasture area, and the highest exchangeable aluminum contents were found in the layers 0.00-0.10 and 0.10-0.20 m of the conventional tillage system. The highest phosphorus availability was found in the layer 0.00-0.10 m of the native forest area. The highest potassium availability was found in the minimum tillage system. The lowest calcium and magnesium values were found in the layers 0.00-0.10 and 0.10-0.20 m of the conventional tillage system. The highest soil organic matter content was found in the layer 0.00-0.10 m of the native forest area. The nutrient availability for plants decreases in soils managed using the conventional tillage system. Soil uses and management systems of little soil disturbance are recommended to minimize environmental degradation in the Amazon biome.

What is the best fertilizer for Marandu and Xaraes palisadegrass production in the short term

espanolRESUMEN Existen varios fertilizantes disponibles comercialmente para aumentar el rendimiento de los pastos, generando dudas sobre cual debe ser escogido para la fertilizacion, especialmente con respecto a la eficiencia y los costos de operacion a corto plazo. El objetivo de este trabajo fue investigar el efecto de los fertilizantes simples y compuestos sobre la produccion, la composicion quimica y los parametros economicos en una empalizada de Marandu y Xaraes a corto plazo. Se evaluaron los fertilizantes urea, Super N, 08-28-16, 30-00-20 y 20-10-10 en tres cortes de la pradera. La tasa global de macolla, produccion de materia seca, contenido de proteina cruda, nutrientes digestibles totales y energia digestible de empalizada Marandu aumento con la aplicacion de fertilizantes nitrogenados, mientras que la fibra detergente neutra (NDF), fibra detergente acida y contenido de hemicelulosa disminuyeron. La fertilizacion con Super N resulto en una mayor eficiencia por el aumento de produccion por kilogramo de fertilizante aplicado y por unidad de reales (R

ORGANIC MATTER PRODUCTION AND CHEMICAL COMPOSITION OF COVER CROPS FERTILIZED WITH NPK

) invertidos por hectarea. En la pradera de Xaraes el numero de tallos aumento y disminuyo el contenido de NDF con la aplicacion de 20-10-10. La fertilizacion en la empalizada de Marandu con Super N fue mas eficiente desde el punto de vista economico y productivo que la fertilizacion con urea. Comparando ambas gramineas, Xaraes fue mas exigente en fosforo y potasio que Marandu. EnglishABSTRACT Several fertilizers with different efficiency and price are commercially available to increase the yield of pastures, generating doubts about which should be chosen for fertilization, especially regarding short term operation returns. Our objective was to investigate the effect of simple and compound fertilizers on the production, chemical composition and economic parameters of Marandu and Xaraes palisade grass in the short term. The fertilizers Urea, Super N, 08-28-16, 30-00-20 and 20-10-10 were evaluated in three cuts of the pasture. The overall rate of tiller occurrence, dry matter production, crude protein content, total digestible nutrients and digestible energy of Marandu palisade grass increased with the supply of nitrogenous fertilizers, while neutral detergent fiber (NDF), acid detergent fiber and hemicellulose content decreased. Fertilization using Super N resulted in higher production of mass per kilogram of fertilizer applied and per unit of real (R

Carbon and carbon dioxide accumulation by marandu grass under nitrogen fertilization and irrigation

) invested per hectare. The number of tillers of Xaraes palisade grass increased and NDF content decreased with the application of 20-10-10. Fertilization of Marandu palisade grass with Super N is more efficient from the economic and productive point of view than fertilization with urea. Comparing the grasses, Xaraes is more demanding in phosphorus and potassium than Marandu.

ESTABILIDADE AERÓBIA DE CANA-DE-AÇÚCAR IN NATURA HIDROLISADA COM CAL VIRGEM

Univ Jose Rosario Vellano, Inst Ciencias Agr, Rodovia MG 179 Km 0 Campus Univ, BR-37130000 Alfenas, MG, Brazil

Características morfofisiológicas da Brachiaria brizantha cv. Marandu em resposta a adubação fosfatada

Nitrogen (N) is the most limiting nutrient for growth of forage grasses, especially in conditions of low water availability. Therefore, it is important to evaluate the effect of N fertilization and irrigation on the accumulation of carbon (C) and carbon dioxide (CO2) by marandu grass in the Cerrado Paulista, in the rainy and dry seasons. Experiments were conducted to evaluate N fertilization in each season, with and without irrigation. Five N rates were used (0, 50, 100, 150 and 200 kg ha-1 per cutting), using urea as N source, totaling 0, 300, 600, 900 and 1200 kg ha-1 in the rainy season and 0, 100, 200, 300 and 400 kg ha-1 in the dry season. The experiments were arranged in a split-plot randomized block design. There was no significant interaction (p > 0.05) between N and time of fertilization in the irrigated experiment. However, N promoted a quadratic effect in organic matter production (OMP), accumulation of C and CO2 by marandu grass, while there was no influence of the seasons. In the non-irrigated experiment, the interaction between N rates and seasons was significant (p < 0.05) only for the rainy season. Organic matter production and C and CO2 accumulation was greater in the rainy season than in the dry season. Irrigation provided increases of approximately 20% in C and CO2 accumulation. The use of N and irrigation increases the accumulation of C and CO2 by marandu grass, and this increase is higher during the rainy season.