Marandu Grass Research Articles

Enhancing the quality of haylage from tropical grasses with xylanase enzyme

ABSTRACT The objective was to evaluate the effect of adding xylanase on the aerobic stability, chemical composition, fermentative, and microbiological parameters of tropical grasses preserved as haylage. A completely randomised experimental design with a 4 × 2 factorial scheme was used, involving four cultivars of haylage grasses (Andropogon gayanus cv. Planaltina, Panicum maximum cv. Mombasa, Panicum maximum cv. Massai, and Brachiaria brizantha cv. Marandu) with and without xylanase enzyme. There was no interaction between xylanase and cultivar in pH values at haylage opening. Aerobic stability remained intact during 120 h of air exposure. Cultivar significantly affected lactic and propionic acid content, with greater fermentation in Mombasa grass and higher butyric acid in Massai grass. Differences (P < 0.001) in DM content were noted, with Andropogon, Massai and Marandu grasses showing greatest values. Andropogon grass, with and without xylanase, had the highest (P < 0.05) crude protein content. Marandu grass haylage had the lowest neutral detergent fibre (P < 0.05) and acid detergent fibre (P < 0.001) content. Andropogon grass haylage with xylanase had lower (P < 0.001) yeast amounts. Therefore, the xylanase enzyme dose (1.8 g kg−1 DM) did not significantly alter the chemical composition, fermentative parameters, or aerobic stability of the haylage samples across different tropical grass cultivars.

Optimal fertilization of Marandu grass with gelatin industry sludge

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.

Soybean molasses can be used as a substitute for corn in grazing beef cattle supplements during the rainy season.

Soybean molasses (SBMO) is a byproduct derived from the production of soy protein concentrate, obtained through solubilization in water and alcohol. The utilization of SBMO as an animal feed ingredient shows promising potential, primarily due to its low cost and as a potential energy concentrate. This study aimed to assess the intake, digestibility, ruminal parameters (pH and ruminal ammonia - NH3), nitrogen retention (NR) and microbial protein synthesis in grazing beef cattle supplemented with SBMO as a substitute for corn during the rainy season. Five Nellore (10-month-old) bulls with an average initial weight of 246 ± 11.2kg were utilized in a 5 × 5 Latin square design. The animals were housed in five paddocks, each consisting of 0.34ha of Marandu grass (Urochloa brizantha). Five isonitrogenous protein-energy supplements (300g crude protein [CP]/kg supplement) were formulated, with SBMO replacing corn at varying levels (0, 0.25, 0.50, 0.75, or 1.00g-1g). The supplements were provided daily at a quantity of 2.0kg-1 animal. The inclusion of SBMO at any level of corn substitution did not significantly affect the intake of pasture dry matter or total dry matter (P > 0.10). Likewise, the intake of CP and, consequently, the ruminal concentration of NH3 did not differ among the SBMO levels. Increasing the inclusion of SBMO did not have a significant impact on NR (P > 0.10), indicating that animals receiving supplements containing 100% SBMO as a substitute for corn may perform similarly to animals receiving supplements with 100% corn (0% SBMO). Soybean molasses represents a viable alternative energy source for grazing beef cattle during the rainy season and can entirely replace corn without adversely affecting animal nutritional performance.

A new perennial forage module coupled with the ECOSMOS terrestrial ecosystem model: Calibration and evaluation for Urochloa (syn. Brachiaria) brizantha

Pastures represent the main land use type in Brazil and are used for livestock production and maintenance of land ownership. Most pasture areas exhibit signs of degradation related to inadequate management, which affects pasture biomass production. Terrestrial ecosystem models are effective tools for evaluating the economic and ecological returns associated with distinct management scenarios. In this paper, a new forage module implemented in the ECOSystem MOdel Simulator (ECOSMOS) is formulated, and ECOSMOS-Forage model calibration and evaluation results were obtained for estimating tropical forage growth under continuous and rotational stocking methods subject to grazing or cutting regimes. A set of equations to simulate the daily carbon allocation, growth, senescence, and morphological characteristics of Urochloa (syn. Brachiaria) brizantha cvs. Marandu and Piatã were proposed. Biophysical and physiological parameters, including the solar radiation balance, soil water content, evapotranspiration and carbon assimilation, were calibrated and evaluated with one micrometeorological experiment. Additionally, two sets of parameters were calibrated for Marandu grass growth under continuous and rotational stocking. Based on the Marandu parameterization, a third set of parameters, thereby adjusting a few parameters, was derived for the Piatã grass under rotational stocking. The ECOSMOS-Forage model could successfully capture the energy, carbon and water fluxes and biomass dynamics during growth cycles. The net radiation, evapotranspiration and gross primary production were simulated with agreement index (d) values of 0.97, 0.89, and 0.95, respectively, during the calibration phase and 0.98, 0.90, and 0.93, respectively, during the evaluation phase. Regarding model application to simulate forage growth under rotational stocking, the model could estimate aboveground, leaf and stem dry matter accumulation levels with d values ranging from 0.91 to 0.98. Although forage growth is relatively difficult to simulate, compared with annual crops, the results suggested that the model could provide high potential for simulating tropical perennial forage grasses.

SYSTEM DEFENSE OF FORAGE SPECIES SUBMITTED TO LOW TEMPERATURES

This work aims to evaluate the enzymatic system defense of forages exposed to low temperatures. The forage plants alfalfa, sorghum, black oat, marandu grass, pearl millet, mombasa grass, and Bermuda grass were subjected to temperatures of 0.2; -0.9; -1.8; -2.7; -4.1; -4.6 and -6.2 oC for 1 h in a growth chamber in a completely randomized design with six replicates for each species. From the crude leaf extracts were evaluated the enzymes ascorbate peroxidase (APX), catalase (CAT), and superoxide dismutase (SOD) activities. Regression analyses compared the treatments. The biochemical responses of forage species to cold stress are different. The enzymes APX and SOD would play an important role in the response to oxidative stress in the forage species black oat and mombasa grass. In marandu grass and sorghum, SOD was the main cell protector. Pearl millet had a positive stimulus in CAT production, Bermudagrass increases the protein content and SOD activity, and alfalfa increases the protein content and APX activity.

Nitrogenated Fertilization In Pasture Brachiaria Brizantha Cv. Marandu Via Organic Compounds

The objective was to evaluate the quantitative and qualitative effect of fertilization of Brachiaria brizantha cv. Marandu using nitrogen from liquid cattle manure and organomineral fertilizer. The experiment was developed in a pasture already established and soil analysis of this area was made for the necessary corrections. The experimental design was randomized blocks in a 4 x 2 factorial scheme. The treatments consisted of control with 0 kg/ha of N, 3 treatments with application of bovine liquid manure and 3 treatments with organomineral fertilizer in the dosages of 60, 120 and 180 kg/ha of N. Three cuts were made in Marandu grass when the pasture reached 30 cm in height, leaving a residue of 15 cm, the production of DM, leaf production, stem, CP, NDF and ADF were evaluated. At the end of the experiment, the cost of fertilizing with manure and organomineral fertilizer was done. To compare the averages obtained and the morphological components of each sample, the Tukey test at 5% significance was used, with the aid of the SISVAR statistical program. With the highest nitrogen levels of organomineral fertilizer and the bovine liquid manure, a higher CP content was obtained, reaching 9.30; 7.78 and 7.90% in the first cut, with organo 180, 120 and manure 180 respectively. Fertilizations with manure 60 and 180, organomineral 120 and 180 showed the lowest values for NDF in the first cut, the ADF only showed a significant difference in the second cut with organo 60, manure 120 and 60 with the highest values. Organomineral fertilizer in different doses provided higher production, but at a higher cost. Fertilization improved the quality of the forage.

Improved Production of Marandu Palisade Grass (Brachiaria brizantha) with Mixed Gelatin Sludge Fertilization

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.

Effect of chemical or organic fertilizers in mining remnant substrate on forage production and marandu grass morphogenesis

Mining drives economic development, but it frequently alters the fertility of remaining soil or substrates. Increasing organic matter in these substrates has been a critical factor for the successful recovery and establishment of plants. In this study, the development of ‘Marandu’ Urochloa brizantha in a Cambisol substrate, a remnant of bauxite mining, was assessed in the municipality of Poços de Caldas-MG, in response to chemical and organic fertilizers derived from vermicomposting of residues from the production of shimeji mushrooms. An experiment was conducted in a greenhouse, where six treatments, namely: conventional fertilizers (FertConv; FertConv + micro and Cal) and exclusively with the use of vermicompost (20, 40 and 60 t ha-1) were evaluated in a completely randomized design in four replications. Fertilization with vermicompost resulted in significant increases in nutrients. Stem and leaf elongation rates, leaf appearance rate, phyllochron, tiller density and dry matter were influenced by both organic and conventional fertilization. However, the greatest benefits were observed with the application of vermicompost. After 90 days of growth, using conventional fertilization, there were no significant increases in the mentioned variables. The use of vermicompost is effective in improving the fertility conditions of the post-mining substrate, with significant impacts on the development of ‘Marandu’ grass, a fact that can contribute to the recovery of areas impacted by mining. Chemical fertilization based only on chemical fertilizers did not result in increases in TAlC, TAlF, TApF, DPP and DM until 90 days of initial growth of ‘Marandu’ grass.

Effects of Using Different Concentrate Supplementation Levels in Diets of Lambs Fed Tropical Aruana (Megathyrsus maximus) or Marandu (Brachiaria brizantha) Grass: Performance, Digestibility, and Costs of Production

In Brazil, grazing is the main or only source of food for livestock. The appropriate combination of supplementation with concentrate in a lamb’s diet on pasture is an alternative that can be explored to use natural resources to produce quality meat. The aim of the current study was to evaluate the effects of different supplementation levels (0%, 1.5%, and 3% of BW) on the intake, performance, and production costs of lambs grazing on Aruana (Megathyrsus maximus) and Marandu (Brachiaria brizantha) grasses. Thirty-six non-castrated male Suffolk lambs (22.54 ± 2.72 kg) were used. The lambs were evaluated for nutrient intake and digestibility, such as dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and consumption in relation to body weight (% BW), in addition to the average daily gain (ADG), body condition score (BCS), and hot carcass weight (HCW), as well as the rising production cost of each system. The dry matter of the green leaf blades was influenced by the pasture type (p &lt; 0.05), producing 1503.6 vs. 2977.4 kg/ha of Aruana and Marandu grasses, respectively. The concentrate supplementation level influenced the type of pasture (p &lt; 0.05). A higher consumption of DM, CP, NDF, and organic matter was registered for the supplemented animals (p &lt; 0.05) and on Aruana grass. The intake in relation to body weight was significantly influenced by the concentrate levels (p &lt; 0.05). The empty body weight and HCW were significantly influenced by the supplementation levels (p &lt; 0.05). The ADG and feed conversion (FC; kg DM/ADG) were influenced by the supplementation levels and type of pasture. The BCSs differed between the concentrate levels (p &lt; 0.05). The supplementation improved dry matter digestibility. The ADG and FC were superior in the supplemented animals, with an advantage for those grazing on Aruana grass. The slaughter ADG was also higher in the supplemented animals. The lambs’ pasture comprising Aruana grass with 1.5% BW of concentrate supplementation showed improved production and economic results.

Capim marandu sob diferimento em monocultivo e sistema silvipastoril: composição bromatológica e mineral

Abstract This study aimed to evaluate the chemical and mineral characteristics of Marandu grass under stockpiling in monoculture (MC) and a silvopastoral system (SPS) with 12- (SPS12) and 18-m (SPS18) spacing between tree rows. The experimental design consisted of randomized blocks, in which each system was allocated individually. Each treatment was formed in the center of each plot in a 3 × 4 factorial arrangement consisting of three systems (MC and SPS12 and SPS18 between the tree rows) and four stockpiling periods (60, 90, 120, and 150 days), totaling 12 treatments with three replications. No interaction effect was observed between the factors (p&gt;0.05) for crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), phosphorus (P), potassium (K), calcium (Ca), or magnesium (Mg). The CP content decreased with increasing stockpiling days but met the suggested requirement for ruminants up to 75 days. The NDF and ADF concentrations increased, while P and K contents decreased with increasing stockpiling days. Magnesium and Ca concentrations did not differ with stockpiling days. However, a difference was observed only for Mg relative to the evaluated systems, which was higher in MC and SPS12, differing from SPS18. The spacing adopted in the SPS of 12 and 18 m does not negatively influence the nutritional value of the forage plant. The 75-day stockpiling period from March favored the concentration of macronutrients and CP content in Marandu grass in both MC and SPS.

Modelos matemáticos para ajustes na quantificação da volatilização de amônia do fertilizante ureia aplicado em pastagens tropicais

ABSTRACT: In Brazil, urea is the most used nitrogen (N) fertilizer to improve forage production. However, their excessive use can cause environmental impacts through N losses, such as ammonia (NH3) volatilization. Therefore, the current study adjusted and estimated the NH3 volatilization from urea applied on tropical pastures in three rainfall conditions using mathematical models. Data were collected from Marandu grass (Brachiaria brizantha) fertilized with 50 kg N ha-1 during wet, intermediate, and dry conditions. Ammonia volatilization was measured in five semi-open chambers for 21 days. The linear, quadratic, exponential, Gompertz, Groot, and Richards models were tested for fitting and estimating the NH3 volatilization. The Gompertz, Groot, and Richards models generated predictions similar to the observed data, with a high determination coefficient, indicating a better fit of these equations to data, with precision and accuracy. However, the Groot model was selected due to the lowest root mean square error of prediction (0.29 % total N lost as NH3). The greatest N loss as NH3 volatilization occurred in the wet, followed by intermediate and dry conditions (20.2, 17.0, and 11.3 % total N lost as NH3, respectively). Therefore, nitrogen losses as NH3 volatilization after application of 50 kg N ha-1, as urea source, are altered according to the weather conditions, reaching 20% of N added in the wet rainfall period. The Groot model is recommended for fitting and estimating the NH3 volatilization from urea applied on Marandu grass pastures in the wet and dry rainfall conditions.

Marandu grass under deferment in monoculture and silvopastoral system: chemical and mineral composition

Resumo O objetivo deste trabalho foi avaliar as características bromatológicas e minerais do capim Marandu sob diferimento em monocultivo (MC) e em sistema silvipastoril (SSP) com 12 (SSP12) e 18 m (SSP18). O delineamento experimental foi em blocos ao acaso, onde cada sistema foi alocado individualmente. No centro de cada parcela formou-se cada tratamento em fatorial de 3 × 4, composto por três sistemas (MC e SSP12 e SSP18 entre as fileiras das árvores) e quatro períodos de diferimento (60, 90, 120 e 150 dias), perfazendo doze tratamentos com três repetições. Não houve efeito de interação entre os fatores (p&gt;0,05) para proteína bruta (PB), fibra em detergente ácido (FDA), fibra em detergente neutro (FDN), fósforo (P), potássio (K), cálcio (Ca) e magnésio ( Mg). O teor de PB diminuiu com o incremento nos dias de diferimento, mas até os 75 dias atendeu a demanda sugerida para ruminantes. As concentrações de FDN e FDA aumentaram, enquanto os teores de P e K diminuíram com o incremento nos dias de diferimento. A concentração de Mg e Ca não diferiu com os dias de diferimento. No entanto, em relação aos sistemas avaliados houve diferença apenas para Mg, que foi maior em MC e SPS12, diferindo de SPS18. O espaçamento adotado no SSP de 12 e 18m não influencia negativamente o valor nutricional da planta forrageira. O período de diferimento de 75 dias a partir de março favoreceu a concentração de macronutrientes e o teor de PB no capim marandu tanto em MC quanto nos SSP.

Grãos secos de destilaria em suplementos para bovinos a pasto

Abstract The objective was to evaluate the inclusion of increasing levels of DDG on nutrient intake and digestibility and ruminal fermentation in cattle kept on pasture. Five castrated male steers, fitted with a ruminal cannula, weighing 450±50kg, 18 months old, kept on Marandu grass pasture were used; and distributed in a 5x5 Latin square. DDG was included in the supplements in the following proportions: 0, 100, 150, 200 and 300 g/kg DM. The data were analyzed and subjected to analysis of variance, at a significance level of 5%, being evaluated by simple polynomial regression. The total availability of pasture and green matter presented averages of 2.0 Ton/ha and 1.3 Ton/ha, respectively, allowing selectivity by animals. The consumption of pasture (P=0.032), MS (P=0.041), MO (P=0.022), and PB (P=0.035) showed quadratic behavior with the inclusion of DDG in the supplements, where the highest consumption for both corresponded to the supplements with 100 and 200g/kg inclusion. The digestibility of NDF (P=0.001) and OM (P=0.046) also suffered a quadratic effect (P&lt;0.05), noting that at levels above 200g/kg it can be reduced. N-consumed also suffered a quadratic effect (P=0.032) with an increase in the inclusion of 100, 200 and 300g/kg of DDG, being linked to the protein fraction of DDG. The levels of Isovalerate (P=0.0001), AGCR (P=0.004) and CH4 production (P=0.022) decreased linearly, indicating a decrease in the energy levels of the animals. Therefore, levels between 150 and 200g/kg of DDG are recommended in supplements for cattle kept on pasture.

Fermentation quality and nutritional value of marandu grass silage with dehydrated banana peel

The objective of this study was to evaluate the fermentation profile and nutritional value of Marandu grass silage (Urochloa brizantha (Hoschst.Ex. A. Rich) R. D. Webster cv. Marandu Syn. Brachiaria brizantha (Hochst. Ex A. Rich) Stapf cv. Marandu} with different levels of inclusion of dehydrated banana peel. The experiment was conducted in a completely randomized design with marandu grass with five levels of dehydrated banana peel (0, 10, 20, 30 and 40% of natural matter) with eight replicates. The data collected were submitted to analysis of variance and, when the "F" test was significant, the inclusion levels of the pre-dried banana peel were analyzed utilizing orthogonal polynomials and linear and quadratic regression models. The mean values of N-NH3 were adjusted to the linear regression model (p &lt; 0.01), while the pH values had the lowest value of 4.3 with the inclusion of 15% of banana peel. The mean values of the gas loss (PG, P = 0.01) and the dry matter recovery (RMS; P = 0.01) were adjusted to the quadratic regression model, with a minimum point of 16.15% for losses and 21% as the maximum point for dry matter recovery. The rate of degradation potential degradability of the dry matter (SD; P = 0.74) did not vary with the inclusion of the banana peel. The potential degradability standardized at 2, 5 and 8% was adjusted to the regressive linear regression model (p &lt; 0.01), and for each percentage point of inclusion of the banana peel, there was a reduction of 0.23, 0.14 and 0.10%, respectively. The inclusion of 10 to 20% dehydrated banana peel in the marandu grass silage improves the fermentation profile and the nutritional value of the silage

Chitosan associated with technical cashew nut shell liquid in supplements for grazing beef steers: nitrogen balance and rumen metabolism

ABSTRACT The aim of this study was to evaluate the inclusion of the chitosan (CHI) and technical cashew nutshell liquid (CNSLT) on nitrogen metabolism and ruminal fermentation on pasture system. Five steers (5 × 5 Latin square); kept of Marandu grass and supplemented daily by up to 0.4% BW. The experimental diets were: CON (mineral supplement); PRO (protein supplement); CHI supplementation; CNSLT supplementation and CC (CHI + CNSLT supplementation). Animals supplemented with CNSLT showed a reduction of pasture intake. The combination CC increased the intake of supplement. Steers supplemented with the combination of CNSLT, and CHI showed a higher supplement intake. The ruminal pH for the animals that received the combination of CNSLT and CHI, showed the lowest values. CHI decreased rumen acetate concentration, and increased propionate. Animals fed CC had a higher concentration of short-chain fatty acids (SCFA) and a reduced value for purines. CNSLT increased the excretion of total purines, microbial nitrogen synthesis and crude protein. Animals that received CC showed higher urinary excretion of N compared to the other treatments. The CHI + CNSLT proved to be favourable, with a higher total concentration of SCFA and positive effect on nitrogen balance.

Changes in the skin characteristics of Nellore steers during the rearing phase in hot climate pasture supplemented with protein sources

We hypothesized that the protein source in supplements and the insolation and ambient temperature changes in different seasons could cause changes in the skin of Nellore steers during the rearing phase on warm-climate pasture. The objective of this study was to evaluate the effects of replacing true protein (soybean meal) with NPN (extruded urea) in the supplement on the skin characteristics of steers grazing on Marandu grass pastures. Thirty-six Nellore steers with an average initial weight of 250.0 kg and 15 months of age were used. Skin biopsies were performed at three different times: summer, autumn, and winter. The protein source has effects on the length of the glandular portion, number of follicles, and gland area in steers during the rearing phase at different seasons of the year. In the summer, the skin presented a higher compact structure, while in the autumn and winter, the skin presented a sparser arrangement. Skin from steers that received soybean meal in supplement had a more significant number of follicles in the summer and a smaller area and length of sweat glands. The dermis thickness of steers supplemented with soybean meal was greater than that of urea supplemented. The epidermis thickness and dermis of the steers' skin were greater at the autumn (April). Sweat gland depth was greater in autumn (April) and winter (July) than in summer (December). The protein source in the supplement alters the skin characteristics by increasing of dermis thickness of Nellore steers during the growth phase. The insolation and ambient temperature changes in different seasons alter the skin structure by increasing the epidermis and dermis thickness, sweat glands depth, and glands area of the skin of steers during the growth phase.

Fuzzy Logic and Artificial Neural Network Perceptron Multi-Layer and Radial Basis in Estimating Marandu Grass Yield in Integrated Systems

ABSTRACT The integrated crop-livestock-forest (ICLF) system integrates different components of animal husbandry. The implementation of this system aims at sustainability, seeking to exploit the area as much as possible, in addition to reducing the impact on the physical, chemical, and biological properties of the soil. With technological advances and numerous variables, fuzzy logic, and artificial neural networks (ANNs) have been used for data classification and estimation. This study aims to estimate the Marandu grass yield in integrated systems using the input, volume of rainfall, and experimental period. A performance of approximately 0.077 was observed for the mean square error (MSE), and the radial basis in estimation (RBR) network had an error of 0.255%, which is much lower than that of the multi-layer perceptron (MLP) network and methodology based on fuzzy logic, with errors of 2.713 and 10.840%, respectively, between the obtained and expected output. This indicates that the quality of the grass was better with one or three eucalyptus lines in the ICLF system and demonstrates the application efficiency of the model with a tool for forecasting the Marandu grass yield in the studied soil and climate conditions.

Technical note: Evaluation of an alternative automatic heating-stirring system in the determination of in vitro ruminal dry matter digestibility of forages using the Tilley and Terry method

This study evaluated an alternative heating-stirring system in the determination of in vitro ruminal digestibility of dry matter (IVRDMD) of forages using the Tilley and Terry (TT) method. For this purpose, the IVRDMD of three forage species (Marandu, Tifton 85, and Mombasa) was determined by incubating 500 mg of each dried and ground (1 mm) forage in 50-mL rumen inoculum during 48h, followed by quantification of the incubation residue. Two heating-stirring systems were used: i) heating in a water bath at 39°C with manual stirring every two hours (i.e., traditional system); and ii) heating in an oven with controlled temperature at 39°C and automatic agitation (44 rpm; alternative system); there was no effect of the interaction between the heating-stirring system and the type of forage (p = 0.829) on the IVRDMD of forages. The type of heating-stirring system (p = 0.422) did not affect the IVRDMD of forages. Nevertheless, the IVRDMD values of Marandu grass (system i = 598.7 g kg-1 vs system ii = 599.4 g kg-1) were greater (p &lt; 0.001) than Tifton 85 (system i = 392.1 vs g kg-1 vs system ii = 370.7 g kg-1) and Mombasa (system i = 397.4 g kg-1; system ii = 369.7 g kg-1) grasses. In conclusion, the obtained data indicate that the alternative heating-stirring system produces similar results to those obtained using the traditionally heating-stirring system during the determination of the IVRDMD of forages.

Combining Fully Acidulated Phosphates with Phosphate-Solubilizing Microorganisms for Urochloa brizantha Fertilization

Aimed to evaluate the productive, morphological and nutritional characteristics, in addition to the accumulation of nutrients in the aerial part of Urochloa brizantha cv. Marandu subjected to phosphorus chemical sources and its interaction with phosphate-solubilizing inoculant. The experiment was developed in Colorado do Oeste, RO, Brazil, being adopted a randomized block design with three replications. The treatments consisted of different phosphate fertilizer doses associated or not with phosphate-solubilizing microorganisms (PSM): 0% P; 50% P; 100% P; 50% P + 250 mL ha-1 PSM; 50% P + 500 mL ha-1 PSM; 50% P + 750 mL ha-1 PSM; and 50% P + 1000 mL ha-1 PSM. Triple superphosphate was used as a chemical fertilizer, and fertilization with chemical fertilizer and PSM occurred on November 19th, 2021. The results for the morphological characteristics and yields of Marandu grass showed significant differences. The different arrangements and phosphate doses influenced the green matter yield and dry matter yield, both using the 50% P + 1000 mL ha-1 PSM presented higher yields (3,642.75 kg ha-1 and 1,049.10 kg ha-1, respectively). Higher crop growth rate results in green matter were also found when employing a combination of 50% P + 500 mL ha-1 PSM and 50% P + 1000 mL ha-1 PSM. Dry matter had a significant effect on the bromatological composition, with higher results observed when using 50% P alone (34.55%). Regarding the accumulation of nutrients in the aerial part, the highest P accumulation in Marandu grass was observed when utilizing 100% P, resulting in an accumulation of 15.4 kg P ha-1. Inoculation with PSM for fertilization of U. brizantha cv. Marandu grass does not have adverse effects on the increase in P availability to the plant, resulting in adequate yield and crop development associated with the productive potential of the area.

Soybean performance in succession to the intercropping of corn with marandu grass and pigeonpea in an integrated agricultural production system

Integrated agricultural production systems have been improved with the introduction of Urochloa grasses aiming at obtaining straw for a no-tillage system (NTS) and the increase of legumes, which promote physicochemical improvements in soils and guarantee intensification and sustainability of production. This study aimed to evaluate the agronomic traits and yield of soybean in succession to the intercropping of corn with marandu grass and/or pigeonpea in five populations of plants harvested for silage production. The experiment was carried out in the Cerrado region of Selvíria, MS, Brazil, during the 2016/17 and 2017/18 agricultural years, in an Oxisol. The experimental design consisted of randomized blocks, with four replications. The treatments were arranged in a 2×5 factorial scheme, consisting of off-season corn intercropped with pigeonpea (Cajanus cajan (L.) Millsp.) and off-season corn intercropped with marandu grass (Urochloa brizantha) and pigeonpea, in addition to five sowing densities (0, 6, 12, 18, and 24 seeds m-1). Soybean was planted in succession aiming to evaluate the effect of remaining straw on crop performance. Soybean grown in succession to the triple intercropping of corn with marandu and pigeon pea shows increased productivity.