Acácio Bezerra de Mira

Resumo A ensilagem de gramíneas tropicais apresenta desafios relacionados ao baixo teor de matéria seca, à limitada disponibilidade de carboidratos solúveis e à elevada fração fibrosa, fatores que podem comprometer o processo fermentativo e o valor nutritivo do volumoso conservado. Nesse contexto, a utilização de coprodutos agroindustriais constitui alternativa promissora para otimizar a qualidade de silagens produzidas com gramíneas tropicais. Objetivou-se avaliar o efeito da inclusão de amêndoa de cupuaçu (Theobroma grandiflorum) sobre a composição bromatológica e o perfil fermentativo da silagem de capim Marandu (Urochloa brizantha). Foram testados cinco níveis de inclusão (0, 6, 12, 18 e 24 % da massa verde), com seis repetições, totalizando 30 minisilos, avaliados após 75 dias de fermentação. Determinaram-se o pH e os teores de matéria seca (MS), proteína bruta (PB), extrato etéreo (EE), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), lignina e frações proteicas indigestíveis. A inclusão de amêndoa de cupuaçu elevou os teores de MS, PB e EE, e reduziu FDA e proteína indigestível em detergente ácido, indicando melhoria no valor nutritivo e potencial de digestibilidade. Os valores de pH mantiveram-se dentro da faixa recomendada, caracterizando adequada fermentação. A inclusão de até 20 % de amêndoa de cupuaçu favorece a qualidade bromatológica e o processo fermentativo da silagem de capim Marandu, configurando estratégia sustentável para sistemas de produção animal em regiões tropicais.

The ensiling of tropical grasses presents challenges related to their low dry matter content, limited availability of soluble carbohydrates, and high fiber fraction, factors that can compromise the fermentation process and the nutritional value of the conserved forage. In this context, the use of agro-industrial co-products is a promising alternative to enhance the quality of silages produced with tropical grasses. This study aimed to evaluate the effect of including cupuaçu almond (Theobroma grandiflorum) on the chemical composition and fermentation profile of Marandu grass (Urochloa brizantha) silage. Five inclusion levels (0, 6, 12, 18, and 24 % of fresh mass) were tested, with six replicates, totaling 30 minisilos, evaluated after 75 days of fermentation. The pH and the contents of dry matter (DM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, and indigestible protein fractions were determined. The inclusion of cupuaçu almond increased DM, CP and EE contents, and reduced ADF and acid-detergent indigestible protein, indicating improved nutritional value and potential digestibility. The pH values remained within the recommended range, indicating adequate fermentation. Inclusion of up to 20 % cupuaçu almond improves the chemical composition and fermentation process of Marandu grass silage, representing a sustainable strategy for animal production systems in tropical regions.

New apps have changed the traditional way of learning and teaching; they are also applied as a quickly executed and effective method in agriculture. Soil-app is a web application with a friendly click-point interface built through packages lodged in R software. The app is an advanced model of an open-source platform to support teaching and learning activities in soil analyses and fertilizer recommendations. Soil-app includes soil test interpretation, soil amendment calculations (lime and gypsum), the fertilizer rate for the most important crops in Brazil, an NPK blend calculator, and NPK blend evaluation. It also includes experimental statistical analysis as applied to soil science. Soil-app is a user-friendly and high-performance tool, garnering fast adoption by both students and professionals. It is available for network use through the following link: http://www.genetica.esalq.usp.br/alogamas/R.html

To support rural extension activities for family farming in the western Amazon, we evaluated the production of Mombasa grass (Panicum maximum Jacq) as a function of phosphorus sources (single superphosphate and calcined bone meal) and rates (100, 200, and 400 kg ha-1 P2O5). The experimental design was a randomized complete block, in a 2x3+1 factorial scheme. The use of calcined bone meal yielded a dry matter (1.73 t ha-1 cutting-1) and a plant height (55 cm) higher than the control (1.03 t ha-1 cutting-1 and 35 cm, respectively). How­ever, the values were lower than those obtained with single superphosphate (3.19 t ha-1 DM and 91 cm in height). Regarding the dry matter production in the experimental period (202 days, five cuttings), the calcined bone meal promoted 54% of the production obtained with the use of single superphosphate.

Maintenance of crop residues over soil surface under conservational systems limits incorporation of nitrogen fertilizers into the soil. Application of urea over crop residues enhance N-NH3 volatilization losses, justifying the usage of urease inhibitors or N sources less susceptible to volatilization under such conditions. This study aimed to evaluate volatilization losses from N sources applied over sugarcane straw. A field trial was carried out in a sugarcane field in Iracemapolis, Sao Paulo on a Typic Kandiudox in June 2014. We used a complete block experimental design, with seven treatments and four replications. Treatments included Control [CO], ammonium nitrate [AN], NS30TM (ammonium nitrate-75% and ammonium sulfate-25% fused mixture) [NS30TM], ammonium nitrate plus ammonium sulfate (ammonium nitrate-75% and ammonium sulfate-25% physical mixture) [AN-AS], urea [UR], urea treated with 0.4% Cu and 0.15% B [UR-CuB], urea treated with 530 mg kg-1 of NBPT [UR-NBPT]. Treatments were applied at rate of 100 kg ha-1 N (except CO). Volatilization losses were quantified up to 30 days after fertilization (DAF). Maximum N-NH3 occurred 16 DAF for UR and UR-CuB and 20 DAF for UR-NBPT. Accumulated N-NH3 losses ranged from 20% (UR), 17% (UR-CuB), and 14% (UR-NBPT) of applied N; non-amidic sources showed losses lower than 1%. Adding urease inhibitor to urea shows potential in reducing volatilization losses even under application over large amounts of straw