Grass Brachiaria Research Articles

PHYTOSOCIOLOGICAL SURVEY IN PASTURE AREAS IMPLANTED WITH GRASSES OF THE GENUS BRACHIARIA IN DIFFERENT RELIEFS

The agricultural sector is essential to the Brazilian economy, contributing 26% of gross revenue in 2021 and 24.8% in 2022. Brazil, the world's largest beef producer, depends on pastures as the main source of feed for its cattle, with Brachiaria grass playing a significant role. role. Inadequate management of these areas often leads to degradation, characterized by the proliferation of weeds, which require intervention. The study was carried out with the objective of carrying out a phytosociological survey in pasture areas at different altitudes to evaluate the floristic composition and identify the forage potential or harmful characteristics of the species present. Phytosociological surveys were carried out in pastures at IFES – Campus Santa Teresa, ES, in two areas with distinct topographic features (hills and plains). The species were identified and classified as palatable, toxic or unpalatable. Sampling occurred during the dry (winter) and rainy (summer) seasons, and species were quantified according to frequency, density and abundance. A total of 47 species distributed in 14 families were identified. The Fabaceae family was the most prevalent, followed by Amaranthaceae and Malvaceae. Alysicarpus vaginalis (IVI 49.06) was dominant in the hillside area (Area A), while Cyperus rotundus (IVI 115.25) stood out in the plain area (Area B). The similarity index between the areas was 26.42%. The study highlighted the diversity of species in Brachiaria pastures, emphasizing the need for targeted management to control unpalatable and toxic plants and, at the same time, optimize forage potential. The low similarity between the areas suggests distinct ecological dynamics.

Comparison Between Vetiver and Brachiaria Grass in Erosion Control in Tropical Climate

Comparison Between Vetiver and Brachiaria Grass in Erosion Control in Tropical Climate

Incidence of Photosensitization in Husbandry Animals: A Meta-Study on the Effects of Feed Diversity and Feed Choice

As this is a meta-study, we examined whether plant species diversity in the feed and the possibility of feed choice would influence the number of cases of photosensitization in farm animals. We evaluated 110 scientific references which described 172 cases of photosensitization worldwide, mainly in husbandry animals between 1926 and 2022. More than 50% of the cases occurred in South America and Australia. Among the animal species, sheep and cattle were statistically overrepresented. A total of 35 organisms were revealed to be phototoxic: 24 herbs, 2 grasses, 7 woody species, and 2 kinds of fungi. Animals developed mainly secondary photosensitization due to fresh feed (71.8%) of normal quality (88.1%), indicating that the phototoxic agents are from liver-toxic plants such as the grass Brachiaria and the herb Froelichia. Horses fell ill chiefly with primary photosensitization due to directly acting phototoxic agents of plant species such as the herbs Medicago and Pastinaca, both in fresh and conserved feed. Goats manage to avoid phototoxic plants under both high and low feed diversity if they still have free choice between plant species. High feed diversity reduced the incidence 2.4-fold, while enabled selection possibility even reduced it 7.5-fold. Since the lack of choice between forage plants was revealed to be the main cause of photosensitization, this knowledge could be used to prevent the disease in livestock.

The supply of phosphate fertilizers affects the uptake of macronutrients and the productivity of Brachiaria cultivars during the establishment period

Phosphate fertilizer is necessary in Brachiaria species to boost fodder yield and nitrogen uptake. Know Plant response the phosphate guides nutrient dosing for optimal growth. The goal was to assess how phosphorus (P) dose affected forage production and macronutrient uptake in forage plants during the establishment period. The experimental design was in a 9 × 2 factorial scheme. Nine forage plants of the genus Brachiaria were evaluated: B. decumbens cv. Basilisk, B. humidícola cv. BRS Tupi, B. humidícola, B. ruziziensis, B. brizantha cvs. Marandu, BRS Piatã, Xaraés, BRS Paiaguás and hybrid (B. brizantha × B. ruziziensis) cv. BRS Ipyporã, two doses of P: 6 and 72 mg/dm−3 of P. At the lowest dose of P, the most productive forages were Paiaguás and ruziziensis. In contrast, at the highest dose of P, the forages ruziziensis, Basilisk, Piatã, Paiaguás and Xaraés were the most productive. When compared to the use of 6 mg/dm−3 P, dose of 72 mg/dm−3 P generated an increase in forage production of 803%. The greater forage production provided by the higher P content in the soil is reflected in greater uptakes of macronutrients by forages, following the decreasing order of N > K > Mg > Ca > S = P. The highest efficiencies to produce 1 g of dry matter (DM) at doses of 6 and 72 mg/dm−3 of P were observed in the Paiaguás and humidicola, respectively. In soils with more readily available phosphorus, macronutrient conversion into plant material is more effective. As a result, grasses of the genus Brachiaria generate more DM with less mineral content.

Pixels to pasture: Using machine learning and multispectral remote sensing to predict biomass and nutrient quality in tropical grasslands

The livestock sector in rural Colombia is critical for employment and food security but is heavily affected by climate and its change. There is a need for solutions to address key challenges arising from vulnerabilities that impact the productivity and sustainability of forages and the livestock sector. Increasing the yields of forage crops can improve the availability and affordability of livestock products while also easing the pressure on land resources. This study aims to develop remote sensing-based approaches for forage monitoring and biomass prediction in Colombia to support decision-making towards increased productivity, competitiveness and reduction of environmental impacts. Ten locations were sampled between 2018 and 2021 across climatically distinct areas in Colombia, comprising five farms in Patía in Cauca department, four farms in Antioquia department, and one research farm at Palmira in Valle de Cauca department. Ash content (Ash), crude protein (CP %), dry matter content (DM g/m2) and in-vitro digestibility (IVD %) were measured from Kikuyu and Brachiaria grasses during the field sampling campaigns. Multispectral bands from coincident Planetscope acquisitions along with various derived vegetation indices (VIs) were used as predictors in the model development. For each site and forage parameter, the importance of specific predictors varied, with the NIR band and Red-Green ratio generally performing best. To determine the optimum models, the effects of using a 1) averaging kernel, 2) feature selection approaches, 3) various regression algorithms and 4) meta learners (simple ensembling and stacks) were explored. Algorithms belonging to classes of commonly used models; Decision Trees, Support Vector Machines, Neural Networks, distance-based methods, and linear approaches were tested. The performance evaluation based on unseen test data revealed that CP and DM prediction performed moderately well for all three sites (R2 0.52–0.75, RMSE 1.7–2 % and R2 0.47–0.65, RMSE 182–112 g/m2 respectively). The best performing models varied by site and response variable, with Regularized Random Forest, Partial Least Squares, Random Forests, Bagged Multivariate Adaptive Regression and Bayesian Regularized Neural Networks being the top performing algorithms and Random Forest Stack being the best performing meta learner. The workflow and thorough analysis of performance affecting factors presented in this study can benefit timely grassland monitoring and biomass prediction at the local level and help contribute to the sustainable management of tropical grasslands in Colombia.

The effects of microalgae use as a biofertilizer on soil and plant before and after its anaerobic (co-)digestion with food waste

The increase in food waste generation has resulted in significant challenges for its sustainable management. Anaerobic digestion coupled with microalgae-based ponds for digestate treatment can be used as a low-cost eco-friendly technology approach. In this case, microalgal biomass harvested from the ponds may be valorized into bioenergy (biogas) and soil conditioner and/or biofertilizers. The aim of the present study was to evaluate the microalgal biomass produced from a food waste digestate treatment ponds as agricultural fertilizer. For this purpose, microalgal biomass was tested before and after anaerobic digestion and co-digestion with food waste, exploring its potential for valorization. The inorganic fertilizer urea and soil with no fertilization were also used as treatments. The experimental design consisted of applying the treatments in pots cultivated with hybrid grass Brachiaria cv. Sabiá and distributed in randomized blocks in a controlled greenhouse. Microalgal biomass was mainly composed by Scenedesmus sp.. The assessed parameters showed comparable results on plant growth (i.e. number of tillers, fresh and dry matter and Chlorophyll content index) for fresh and digested microalgal biomass and inorganic fertilizer. Furthermore, it was observed that fresh microalgae provided the highest Phosphorus content in the leaf (21 %). Additionally, there were increases of 9 % in Nitrogen and 12 % in organic matter in the soil after applying digested microalgae compared to the control group without any fertilization. Finally, experimental data obtained suggests that microalgae-based biofertilizer holds the potential to replace inorganic fertilizer as a nutrient source. Moreover, it contributes to the valorization of by-products from organic waste treatment.

Mathematical models for predicting protodioscin in tropical forage grasses

Protodioscin is a saponin present in grasses that can lead to losses in animal production. Our hypothesis was that mathematical models can accurately and precisely predict the protodioscin concentration in tropical grasses. We evaluated the ability of four mathematical models to describe the protodioscin concentration in Brachiaria and Panicum cultivars with different regrowth periods. Six cultivars of Panicum: Aruana, Massai, Mombaça, Tanzânia, Tamani, and Zuri; and five of Brachiaria-grass: Marandu, Paiaguás, Piatã, Xaraés and Basilisk. Protodioscin concentration evaluations were carried out at 51, 84, 110, and 111 days of age. Linear, Quadratic, Exponential, and Logarithmic models were evaluated, and the adequacy of the models was verified. The models were compared for accuracy and precision by pairwise mean squared error analysis and the delta Akaike information criterion. The models did not differ from each other in terms of accuracy and precision. The exponential model showed a high ability to explain the observed variability between protodioscin concentration and plant age for Brachiaria grasses. Panicum grasses have constant protodioscin concentration. Mathematical models are capable of predicting the protodioscin concentration in grasses of the genus Brachiaria based on plant age. We recommend Exponential model to predict the concentration of protodioscin in Brachiaria grasses.

A Modified Climate‐Smart Push‐Pull Technology for the Management of Fall Armyworm (Spodoptera frugiperda) in the Semiarid Lands of Kenya

Successful use of push‐pull technology in the control of fall armyworm (Spodoptera frugiperda Smith) in maize has been limited to areas that receive optimal rainfall as opposed to the semiarid areas. This study sought to determine the viability of a modified push‐pull technology designed for drier areas. The technology involved the use of the drought‐tolerant Brachiaria grass as a potential replacer of Napier grass as a pull crop, alongside drought‐tolerant green‐leaf Desmodium (Desmodium intortum) and edible legumes as push crops. The study was conducted in Mbeere South Subcounty in Embu County, Kenya. The experiments were laid out in split plots arranged in a randomized complete block design with three replications. The main plots contained Napier and Brachiaria grasses as comparative pull crops while the subplots tested the performance of the drought‐tolerant green‐leaf Desmodium and edible legumes (cowpea, pigeon pea, and green gram) as push crops. A maize monocrop was used as the negative control. The pest dynamics were determined using the area under damage/pest curve (AUDPC). The highest pest incidence was observed in the maize monocrop treatments with AUDPC range of 64–65.5 as compared to the intercrop treatments with AUDPC range of 45–56. The AUDPC for damage severity ranged from 24 to 24.5 in the maize monocrop treatments and 15.5 to 18.7 in the intercrop treatments. These findings implied that the drought‐tolerant green‐leaf Desmodium and the edible legumes can be adopted as effective push crops in the modified push‐pull technology. Brachiaria and Napier grasses portrayed similar suitability as pull crops implying that the two can be used interchangeably as pull crops based on farmers’ preference. This study confirmed the viability of the modified climate‐smart push‐pull technology in the management of fall armyworm in dryland areas.

Morphological and molecular characterization of the rust fungus, Phakopsora apoda causing leaf rust on Brachiaria grass in Rwanda

Brachiaria grass is one of the major forages that plays a key role in push pull technology. Different diseases including leaf rust caused by rust fungus, Phakopsora apoda have recently become an important challenge resulting in yield loss of Brachiaria grass in different countries including Rwanda. The objective of this study was to provide morphological and molecular characteristics of Phakopsora apoda causing Brachiaria leaf rust. Spores isolated from rusted Brachiaria leaves collected in five districts of Rwanda were analyzed. Samples were put in paper bags and left at room temperature for two days. Thereafter, spores were removed using brushes and put in eppendorf tubes, stored at 4oC in darkness for further characterization. For morphological characteristics, colour and measurements of spores were recorded using Optika B-350 microscope with installed camera and calibrated micrometer. Multigene analysis using rust specific primers and large subunit (LSU) of nuclear ribosomal RNA was performed for molecular characterization. The results indicated that the colour of spores was yellowish or brownish while the shape was ellipsoidal or circular with average measurements of 25.1µm and 16.8µm for length and width respectively. Primers amplified the size of DNA between 1291bp and 1381bp and the size between 874bp to 882bp for rust specific primers and LSU respectively. The identity of the sequence was 96% with e-value of 0, sequence coverage of 60% for rust primer and the sequence identity was 94.97% to 95.37%, sequence coverage of 99% to 100% and e-value of 0 for LSU primer. All sequences recovered from five isolates of leaf rust matched to the genebank accession number MG461668.1 for both rust specific and LSU sequences. The results of this study provide useful information to develop effective options for leaf rust disease management in Rwanda. Key words: Internal transcribed spacer, large subunit, nuclear ribosomal RNA, Phakopsora apoda, sequence, spore.

First report and biological characteristics of Heterorhabditis amazonensis in the state of Paraná, Brazil.

Entomopathogenic nematodes (EPNs) from Heterorhabditidae and Steinernematidae families are extensively used to control insect pests. In Brazil, however, relatively few studies have identified and characterized these entomopathogens. The objective of this study was to identify and characterize an EPN isolate obtained from soil samples collected in the state of Paraná, Brazil. An isolate (UEL 08) of Heterorhabditis was detected in a soil sample collected from a pasture area cultivated with Brachiaria grass in Londrina, state of Paraná, Brazil (23°34'311''S, 050°58'298''W), using the insect-baiting technique with Galleria mellonella larvae as hosts. The nematode was identified through morphometric studies and molecular analyses based on amplification of the rDNA ITS region. Although we identified certain morphometric differences compared with the original description, the molecular data indicated that the ITS sequence obtained for the UEL 08 isolate is identical to the reference sequence of H. amazonensis (DQ665222) and presented 100% similarity. Thus, the findings of our morphological and molecular studies confirmed that the isolated nematode is H. amazonensis, which is the first time this species has been registered in Paraná. Study of the biological characteristics of H. amazonensis (UEL 08) revealed that the isolate has two distinct life cycles - one short (216 h) and the other long (288 h) - and produces two generations in both cycles. We observed that H. amazonensis (UEL 8) was pathogenic and virulent to the three evaluated hosts, although with different virulence against these hosts. The larvae of G. mellonella and Alphitobius diaperinus were more susceptible than adult Dichelops (Diacereus) melacanthus, with 100%, 85%, and 46% mortality, respectively. Furthermore, an in vivo production assay revealed a mean daily yield of 3.4 × 103 infective juveniles/g host larvae.

Adaptation Trail of Brachiaria Grass Varieties in West and Kellem Wollega Zones of Oromia, Ethiopia

The experiment was carried out to identify better adaptable, forage yielding and quality of the tested variety/ies in study area

Weed Management Practices on Growth, Yield and Economics of Kharif Grain Sorghum

In the Kharif grain sorghum growing areas of Karnataka, the sorghum production suffers greatly due to weed problem, which offers limitations to crop. It was found that weed infestation become unmanageable throughout the growing period by the traditional methods of interculturing and manual weeding due to continuous and heavy rains during entire vegetative and early reproductive stages of Kharif sorghum. Hence, integration of herbicides with some cultural operations and use of pre-emergence, post-emergence herbicides in combination with mechanical methods can prove to be more successful. A field experiment entitled “Weed management in kharif grain sorghum” was conducted during Kharif 2019 at ARS, Hagari in deep black soil with neutral reaction (pH 7.50), organic carbon (5.5 g kg-1), available nitrogen (248.00 kg ha-1), available phosphorus (36.75 kg ha-1) and available potassium (312.00 kg ha-1). An experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. There were fourteen treatments comprising of weed management practices. The dominant weeds observed in the experimental fields were among grasses Brachiaria reptans, while in broad leaved weeds, Amaranthus viridis and among sedges, Cyperus rotundus. Significantly lower population of grasses, sedges, and broad leaved weeds, weed dry weight, weed index (%) and higher weed control efficiency throughout the crop growth period was noticed in sequential pre-emergence application of atrazine 50 WP @ 0.50 kg a.i. ha-1 as PE fb 2,4-D Na Salt 80 WP @ 0.75 kg a.i. ha-1 as PoE at 25 DAS except weed free treatment. Atrazine 50 WP @ 0.50 kg a.i. ha-1 as PE fb 2,4-D Na Salt 80 WP @ 0.75 kg a.i. ha-1 as PoE at 25 DAS recorded significantly higher plant height, dry matter accumulation, leaf area, test weight, grain yield, straw yield, harvest index, gross return, net return and benefit cost ratio (160.8 cm, 183.4 gplant-1, 24.1 dm2 plant-1, 30.53 g, 4195 kg ha-1, 9891 kg ha-1, 29.80 %, Rs. 1,03,675ha-1, Rs. 71,636 ha-1and 3.24, respectively) except weed free and it was on par with atrazine 50 WP @ 0.50 kg a.i. ha-1 as PE fb IC at 25 DAS and HW at 25 DAS and IC at 40 DAS.

Maize-Brachiaria grass intercropping: A meta-analysis of major productivity drivers in Brazil

Context or problemIncreasing crop intensification while enhancing soil conservation is an important aspect of global food security. Intercropping (syn. interseeding) between cash crops and tropical forages improves soil cover, prevents soil erosion, and enhances land use via crop and livestock integration. In Brazil, intercropping between maize (Zea mays L.) and Brachiaria grass (Urochloa spp.) is the most commonly adopted system, with opportunities for expansion across tropical and subtropical landscapes worldwide. Nonetheless, there is little consensus on the effects of intercropping on the performance of each individual crop species. Objective or research questionA meta-analysis was conducted to quantify the effect of intercropping on maize grain yield and Brachiaria grass biomass production and to understand the impact of environmental and management factors on intercropping performance. MethodsA literature search was conducted to retrieve peer-reviewed studies carried out on this intercropping system under field conditions. Manuscripts were scrutinized and included in this meta-analysis when they met the following criteria: i) data on maize grain yield and Brachiaria grass biomass under intercropping were reported, ii) inclusion of a control treatment (monocropping) for at least one species, and iii) field trials with at least three randomized replications. Our database included 429 data points extracted from 56 published manuscripts from all regions of Brazil. ResultsRelative to monocropping, intercropping reduced maize grain yield (−5.6 %) and Brachiaria grass biomass production (−64 %) in all scenarios. The intercropped maize grain yield was less affected under the following conditions: i) in the subtropical climate zone (−3.6 %), ii) sowing the intercrop early in the season (−5.8 %), iii) applying monocot-selective postemergence herbicides (−4.4 %), iv) relay temporal arrangement (−2.8 %), and v) with N and P fertilization rates above 150 and 35 kg ha-1, respectively. In relative terms, Brachiaria grass performance was more affected by i) intercropping adoption, with a reduced biomass penalty under a tropical climate (−63.9 %), ii) late sowing time for the intercrop (−59.5 %), iii) application of N fertilizer at a rate above 50 kg ha-1 (−70.5 %), and iv) non-use of postemergence herbicides (−21.9 %). ConclusionMaize-Brachiaria grass intercropping was an effective alternative to produce residue (no-till system adoption) or forage (crop-livestock integrated system adoption) with reduced maize grain yield penalties, diversifying cropping systems in Brazil. Implications or significanceDespite the production penalties for both crop species, considering different relative values, specific management practices and climate conditions could minimize yield penalties. Scenarios favoring maize yields may be preferred for intercropping systems focused on improving soil quality; in contrast, Brachiaria grass biomass may benefit the integration of crop-livestock systems focused on ensuring forage production.

Effects of Organic Fertilization on Growth Response of Brachiaria (Mulato II) in Lushoto, Tanzania

The smallholder livestock keepers in Tanzania, like any other country in sub-Saharan Africa, depend heavily on the natural pastures that lack quality and nutrients for livestock. Efforts to establish pasture with Bracharia grass in most parts of sub-Saharan Africa to supplement the deficiency are inevitable. This study aimed to investigate the effects of farmyard manure fertilisation on the performance of Brachiaria grass (Mullato II) at Ubiri Village, Lushoto District, Tanzania. The study used two treatments, i.e., the number of harvest and fertility improvement options, whereby Randomised Complete Block Design (RCBD) with three replications were used. Data was collected on plant tiller number per bunch, tiller height (m), biomass (tha-1) and leaf area indices per treatment in replications. R software version 3.5.0 was employed to analyse the gathered data sets. We compared the mean difference using the standard error of the mean. The result indicated that tiller height, number of tillers, biomass yield and leaf area index, of the hybrid Brachiaria grass had increased significantly (P<0.05) by 59, 48, 68%, and 76 %, respectively, in the second Harvest (i.e., 22 weeks). It was revealed further that manure fertilisation showed positive effects on the growth response of the grass. The study recommended that the integration of farmyard manure should be promoted in Tanzania and elsewhere in sub-Saharan Africa. Moreover, a study should be conducted to investigate the effects of farmyard manure fertilisation on the nutritional value of Brachiaria grass in the area studied

PSIX-22 Performance, Digestibility, and Blood Parameters in Pregnant Beef Cows Fed Total Mixed Ration Silages

Abstract The aim of this study was to investigate the effects of two total mixed ration (TMR) silages (low and high rumen undegradable protein; RUP) on digestibility, blood parameters, and performance in pregnant beef cows. Thirty-three mid-gestation (~130 d of gestation) Tabapua beef cows were randomly assigned to 1 of 2 treatments: 1) a TMR silage containing Brachiaria grass, soybean hulls, urea, and mineral mix (low RUP; n = 16) or 2) a TMR silage containing Brachiaria grass, DDG, and mineral mix (high RUP; n = 17). The concentration of A1 fraction was, on average, 12.9% and 34.0% of N in low and high RUP silages, respectively. A preservative with a blend of organic acids, surfactants, and activated propionates was applied in both silages. Pressed bag silos were used to conserve silages for 7 wk. Cows were housed in individual pens for 100 d. During a 4-d digestion period (at 50 d of housing), fecal samples were collected for measurement of nutrient digestibility using undigested neutral detergent fiber as a marker. Blood parameters were collected at the last day of housing. Statistical analysis of experimental data was performed using the GLM procedure of SAS 9.4. Diet, calf sex (male or female), and interactions between these factors were considered fixed effects. No differences were obtained for initial BW. High RUP diet showed greater final BW (P = 0.0004) and ADG (P = 0.0003). Cows fed high RUP gained 50 g/d, while cows fed low RUP diet lost 445 g/d. Dry matter intake was greater by 23% (P < 0.0001) in cows consuming high RUP silage. Dry matter, CP, and NDF digestibility did not differ between treatments. Regarding blood parameters, no differences were observed for glucose at 0 h and 4 h post-feeding. Plasma urea at 0 h post-feeding was greater in cows fed low RUP silage (P = 0.0003). However, no differences were observed for plasma urea at 4 h post-feeding. The plasma concentrations of non-esterified fatty acids (P = 0.017) and beta-hydroxy-butyric acid (P = 0.002) were greater in cows consuming low RUP diet. Overall, feeding pregnant cows during mid-gestation with TMR silage containing high RUP promotes greater performance.

Effect of Growing Crops and Rice Soil on Growth, Regeneration and Yield of Grass Brachiaria humidicola Grown in Central Vietnam

Effect of Growing Crops and Rice Soil on Growth, Regeneration and Yield of Grass Brachiaria humidicola Grown in Central Vietnam

Powder and agglomerated free-choice minerals for grazing cattle: animal responses and chemical and physical alterations of the mineral mixture

ABSTRACTThe aim was to evaluate the animal response and the chemical and physical changes of free-choice mineral mixtures fed to grazing cattle. Growing beef cattle were fed either powder (POW) or agglomerated (AGL) mineral mixtures in three different experiments (Exp.), carried out in pastures of Brachiaria grass. In Exp. 1 and 2, the mineral mixtures were disposed in unsheltered troughs (POWun vs. AGLun), being delivered once (D0, Exp.1) or twice (D0 and D8, Exp. 2), throughout 14-day periods. In Exp. 3, POWun and AGLun were additionally compared to POW in sheltered troughs (POWshe), and the mineral mixtures were disposed in D0, throughout 21-day periods. Non-consumed supplement was removed and sampled on D14 (Exp. 1 and 2) or D21 (Exp. 3). Evaluations included average daily body weight gain (ADG), daily disappearance of the supplement (DSD), penetration force of the supplement mass, faecal chemical composition and serum levels of Ca, P and Mg. In Exp. 1, no effects were observed on ADG and faecal mineral concentrations, however, changes in mineral concentrations and a 40% reduction in Na concentration in the supplement were observed, compared to the initial concentration. AGLun had a lower penetration force. In Exp. 2, there were no effects on DSD and faecal mineral concentrations. POWun showed a smaller reduction in Na content compared to AGLun, and AGLun showed lower penetration force. In Exp. 3, the treatments did not affect ADG, but there was a trend towards higher DSD and serum phosphorus (P) concentration for AGLun (p = 0.08). Higher faecal Na concentration was observed for AGLun and higher Na concentration occurred in non-consumed mixture of POWshe. Mineral supplements offered in uncovered troughs showed altered chemical and physical characteristics, with possible effects on supplement intake. However, the general changes are unlikely to alter animal performance.

Characterization of new endophytic bacterial strains isolated from brachiaria grass

Characterization of new endophytic bacterial strains isolated from brachiaria grass

Environmental and agronomic assessment of soil conditioners produced from bauxite residue and oil palm wastes

Soil conditioner is class of products used to enhance physics, physicochemical or soil biological activities, being able to recover disturbed or nutritional unbalanced soils. The formulation of a soil conditioner composed by bauxite residue (BR), and organic oil palm wastes, as raw materials, was recently proposed as an innovative strategy for the Brazilian acid soils amendment. Here we show the results of soil conditioner amended soil leaching tests and agronomical performance. The soil conditioners were formulated by BR mixed with decomposed POC (palm oil compost) and non-decomposed POMW (palm oil mill waste) oil palm wastes, in the proportion of 25% BR + 75% POC (T1) and 50% BR + 50% POMW (T2), in addition to the treatment with 100% POMW without BR (T3) and limestone at a dose calculated to raise soil pH to 6.0 (T4). Except for T4, all conditioners were applied to the soil at doses of 40, 80, and 120 t ha−1 for leaching tests. The experimental plots were composed of polyvinyl chloride columns, filled with 5 kg of soil, with bottles adapted with hoses at the bottom to facilitate drainage of the leachate. After leaching tests, the respective columns were used as pots for the cultivation of Brachiaria grass, stage with addition of a control composed by undisturbed soil (T5). The pH of the leachates had changes, but the use of BR associated with POMW was similar to the use of limestone. Of the 65 chemical elements evaluated, only nine were identified in the leachate, being most of them considered as plant nutrients. As for soil pH, limestone was slightly higher (6.6) than treatments that had BR (5.5). Brachiaria grass cultivated in the soil amended with conditioners showed similar results of limestone treated soil for the parameters of plant development and showed fertility improvement.

THE ALLELOPATHIC EFFECT OF SORGHUM AND ITS LINKS TO THE EXTRACT COMPOSITION AND THE SORGOLEONE

The use of sorghum on the no-tillage system has contributed to weed control but has generated problems infuture soybean development. The objective of this work was to extract and quantify sorghum root exudate ofthree genotypes to determine the sorgoleone content, the chromatographic profile, and the relative toxicity of the root extracts through the evaluation of germination parameters in soybean (Glycine max), brachiaria grass (Brachiaria decumbens) and beggarticks (Bidens subalternans) seeds under laboratory conditions.Considering the average root density, BRS 716 presented 50% more numbers of hairs per mm² than the othertwo sorghum genotypes. Sorgoleone was found predominantly in the three evaluated sorghum extracts, andthe chromatographic profile detected five other compounds for the BR 007, CMSXS 206 B, and 6 BRS 716compounds. There was a difference between the dry mass of roots, dry mass of extract, and sorgoleone content among the three genotypes, with BRS 716 having the highest ratio of sorgoleone per dry mass of roots, followed by BR 007 B, and CMSXS 206 B. The BR 007 B extract was the one that reduced germination and the germination speed index (GSI) of soybean and hairy beggarticks, followed by BRS 716 and CMSXS 206B. The results showed that sorgoleone is a potent inhibitor of plant germination, but the allelopathic actionmay be linked to the composition of each extract and not specifically to the sorgoleone.