Joadil Gonçalves de Abreu

Novas tecnologias são necessárias, para otimizar o fertilizante nitrogenado aplicado nas forrageiras tropicais e uma delas é a combinação com microrganismos promotores de crescimento como o A. brasilense (Azospirillum brasilense). Assim, objetivou-se avaliar a associação de A. brasilense a fontes de fertilizantes nitrogenados na produção acumulada de lâmina foliar (LF), acúmulo de macronutrientes no tecido foliar e a eficiência de uso do nitrogênio (EUN) no capim marandu (Urochloa brizantha cv Marandu). Para isso, foi instalado um experimento a campo no bioma Amazônia Meridional num delineamento experimental em blocos casualizados no esquema fatorial 2x3, sendo com e sem A. brasilense e duas fontes de nitrogênio (ureia comum; ureia revestida) e um nível do fator adubação sem a aplicação de nitrogênio, com 4 repetições. A cada ciclo de crescimento foram aplicadas 40kg de N ha-1 e uma dose de 300mL ha-1 do inoculante, via foliar, A. brasilense, estirpes CNPSo 2083 e 2084, com garantia de 2.0 x 1011. A aplicação foliar de A. brasilense associada à adubação nitrogenada promove aumento médio de 17% na produção de lâmina foliar (LF), no acúmulo de Ca da parte aérea e maior EUN no ambiente amazônico. A ureia revestida proporciona aumento médio de 27 e 91% na LF em relação à ureia comum e sem ureia, respectivamente, aumento na absorção de N, Ca e de Mg, quando inoculadas e de N, P, Ca, Mg e S quando não inoculadas. Independente da inoculação a ureia revestida teve maior EUN do que a ureia comum.

This study determined optimal fertilization levels for Marandu grass (Urochloa brizantha cv. Marandu) as a forage using sludge from the gelatin industry. The experiment was performed in a greenhouse with five treatments: three rates of gelatin sludge application (0, 200, and 300 m3 ha-1), an organo-mineral (100 m3 ha-1 + mineral: 60 mg dm-3 N), and pure mineral fertilizer (100 mg dm-3 N) with six replicates. Plant and stem height, number of tillers, leaves, leaves/tiller, chlorophyll index, dry mass (leaves, roots, and residue), crude protein, neutral and acid detergent fiber, macronutrient, and micronutrient concentrations were measured. Plant and stem height, number of tillers, leaves, and biomass production increased linearly as gelatin sludge dosage increased. There was a linear increase in crude protein with reduction in neutral detergent fiber and acid detergent fiber with increasing gelatin sludge fertilization. Gelatin sludge dosage did not affect the contents of P, Mg, S, Cu, and Fe. Only Mn had a positive linear response to gelatin sludge with reduction at the highest rate. The 300 m3 ha-1 dosage of gelatin sludge increased biomass production and chlorophyll index. In contrast, the organo-mineral fertilizer promoted higher crude protein and lower neutral detergent fiber concentrations in grass. The gelatin sludge dosage of 300 m3 ha-1 improved the nutritive value of Marandu grass compared to mineral fertilizer. Gelatin sludge is a promising pasture amendment for growing Marandu grass as it recycles industrial animal waste for a more integrated livestock-cropping system.

Gelatin industry residues are increasingly used as fertilizer and soil conditioner. However, correct residue dosage is critical for grass development and minimizing environmental impacts. This randomized block design study determined adequate dosage of mixed gelatin sludge (MGS) for Marandu grass production in wet/dry seasons in Brazil. Five MGS levels (0–200% of required nitrogen) were compared to mineral fertilizer. Agronomic/productivity characteristics, bromatological composition, macro/micronutrient composition of leaves, and soil chemical attributes were evaluated. Agronomic/productivity characteristics were influenced by MGS dose in both dry/rainy seasons, except for leaf blade pseudostem ratio and percentage of leaves/pseudostem. Bromatological composition was influenced by MGS doses in dry/rainy seasons except for dry/mineral material quantities. Marandu leaf tissue chemical composition was significantly influenced by MGS dose, except for potassium, boron, and iron. Chemical composition of four soil layers between 0 and 50 cm influenced MGS dose, except for pH, organic matter, magnesium, copper, manganese, and zinc. GMS dose for Marandu production should be 200% of nitrogen requirement. MGS application increased productivity/quality of Marandu grass. Macronutrients (nitrogen, phosphorus) and micronutrients (calcium, magnesium, sulfur, copper, and zinc) increased in Marandu grass and in the soil (calcium, sulfur, and sodium). The increased sodium level was not limiting.

Gelatin industry residues are increasingly used as fertilizer and soil conditioner. However, correct residue dosage is critical for grass development and minimizing environmental impacts. This randomized block design study determined adequate dosage of Mixed Gelatin Sludge (MGS) for Marandu grass production in wet/dry seasons in Brazil. Five MGS levels (0%–200% of required nitrogen) were compared to mineral fertilizer. Agronomic/productivity characteristics, bromatological composition, macro/micro-nutrient composition of leaves, and soil chemical attributes were evaluated. Agronomic/productivity characteristics were influenced by MGS dose in both dry/rainy seasons, except for leaf blade pseudostem ratio and percentage of leaves/pseudostem. Bromatological composition was influenced by MGS doses in dry/rainy seasons except for dry/mineral material quantities. Marandu leaf tissue chemical composition was significantly influenced by MGS dose, except for potassium, boron, and iron. Chemical composition of four soil layers between 0–50 cm influenced GMS dose, except for pH, organic matter, magnesium, copper, manganese, and zinc. GMS dose for Marandu production should be 200% of nitrogen (N) requirement. GMS application increased productivity/quality of Marandu grass. Macronutrients (N, phosphorus) and micronutrients (Ca, Mg, S, Cu, and Zn) increased in Marandu grass and in the soil (Ca, S, and Na). Increased sodium (Na) level was not limiting.

The aim of this study was to evaluate the agronomic performance of sorghum grown in different combinations of row spacing and plant density, as well as possible interferences on silage quality. No other study dedicated to identifying the interference of plant spatial arrangement on the cultivation of silage material has been developed in the productive context of the Amazon Biome, making it necessary to understand the behavior of the studied factors. The treatments were arranged in a split-plot scheme: the plots corresponded to three row spacings (0.45 m, 0.60 m, and 0.75 m) and subplots at four densities (105,000, 120,000, 135,000, and 150,000 plants ha⁻¹). The agronomic and productivity characteristics of sorghum and the fermentative and bromatological characteristics of forage and silage were evaluated. The sorghum plants showed an increase in plant height and green and dry mass yield when using higher densities (p < 0.05). For the culm diameter variable, an isolated effect of the factors was observed, with reduced diameter when grown closer to inter-row spacing or using higher plant densities. No effect of the factors was found (p > 0.05) for morphological plant components. In silage, wider spacing promoted higher dry matter content. Regarding crude protein in the silage, higher percentages were obtained at closer spacing and higher plant density. The sorghum growing in dense conditions is indicated, given the positive performance in productivity and bromatological composition.

This study aimed to evaluate the fermentation pattern and dry-matter losses in corn (Zea mays L.) silage intercropped with Urochloa brizantha cv. Marandu and Megathyrsus maximus cv. Mombasa grasses in different sowing modalities through crop–livestock integration. The experimental design was in randomized blocks, which were arranged in a 2 × 5 factorial scheme with four repetitions. The first factor consisted of the grass cultivars Marandu and Mombasa. The second factor was the sowing modalities of grasses intercropped with corn: (1) simultaneous row sowing and inter-row corn sowing (no fertilizer); (2) simultaneous row sowing and inter-row corn sowing (with fertilizer); (3) simultaneous sowing with double grass row in the corn inter-row; (4) delayed sowing inter-row at 7 days after corn emergence; and (5) delayed sowing inter-row at 14 days after corn emergence. The forage buffer capacity (BC), silage pH and ammoniacal nitrogen (NH₃-N) content, forage (FORDM) and silage dry-matter (SILDM) percentages, gas losses (GL), effluent losses (EL), and dry-matter recovery (DMR) parameters on the ensilage were evaluated. Only forage BC, silage NH₃-N, and silage DMR variables differed (p < 0.05) from the control silage (monocropped corn) when the integration was carried out. The grass cultivar factors and sowing modalities for BC and NH₃-N variables had an effect. The intercropping of corn and Marandu grass or Mombasa grass, in any grass sowing modality, did not affect the quality of the silage.