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The soil seed bank is key to plant succession. However, agricultural activities have had a great impact on the vegetation and its composition. The aim was to determine the soil seed bank in different grazing agroecosystems in the central part of Veracruz state, Mexico. Richness, abundance, diversity, equity, dominance and similarity of the species were quantified and compared among four agroecosystems (silvopastoral, pasture-trees, traditional grazing, and Acahual or secondary vegetation) in Veracruz, Mexico during the year 2017. Samples were collected. of soil at two depths (0-5, > 5-10 cm). A statistical difference was found in the seed bank (P < 0.05) in silvopastoral at both depths, 0-5 (H’ = 2.13) and 5-10 (H’ = 1.86). Equity and dominance were higher for this agroecosystem (0.86) and for Acahual (0.58) with statistical differences (P < 0.05). No statistical differences were found at sites between depths (P > 0.05). Similarity was greater than 50% at all sites and increased with soil depth. The evidence suggests that the greatest diversity of the seed bank was in silvopastoral from 0 to 5 cm deep. The seed bank has potential for the restoration of vegetation, mainly herbaceous, and can promote the development of shrubs and trees, despite the management of cattle ranching sites.

Water deficit during the dry season is one of the main factors affecting the productivity and quality of pastures. The present work aims at evaluating the effects of water deficit on the morphological and productive characteristics of Urochloa brizantha cultivars grown in Quartzarenic Neosol. The experiment was conducted in a greenhouse under a completely randomized design with a 4×2 factorial arrangement, with four cultivars (Marandu, MG4, MG13 Braúna and MG5 Vitória), two water availability conditions (50% or 100% of field capacity) and six repetitions. Structural, morphogenic and productive variables were evaluated 15, 25 and 35 days after the beginning of treatment application. For all productive characteristics evaluated during 35 days of water stress, it was observed that a 50% reduction in water availability significantly (P

Abstract The objective of this work was to evaluate inoculation response to Azospirillum baldaniorum strain Sp245 in 14 Urochloa cultivars. The evaluated cultivars were: Marandú, Xaraés, Paiaguás, Piatã, Basilisk, B140, Comum, Tupi, H47, Llanero, Ruziziensis, Ipyporã, Mulato, and Convert HD364. Three experiments were conducted to measure root traits: two using soil and one a sterile substrate. Compared with the control, a single application of A. baldaniorum Sp245 increases dry matter accumulation and number of roots in cultivars Marandú, Llanero, Ruziziensis, and Convert HD364. However, after inoculation, cultivars Xaraés and Ipyporã show some root traits with lower values.

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT Vast areas of the Brazilian Amazon have been deforested for the expansion of livestock and the agricultural frontier, which has resulted in soil exhaustion. It is therefore urgent to reduce deforestation and encourage sustainable land use to promote social and economic development in the region. The aim of this study was to evaluate the impact of different land use systems (an agroforestry system, cassava cultivation, non-degraded pasture, native forest) on the chemical properties of the soil (0-40 cm) in the mesoregion of the Juruá Valley, in the state of Acre, Brazil. Principal component analysis showed the soil in the forested area (reference) has greater values for P, Ca2+, Mg2+, K+, Na+, sum of bases, and cation exchange capacity; while hierarchical cluster analysis suggested little dissimilarity to the soil in the agroforestry system, and high dissimilarity to the soil in the areas of cassava cultivation and pasture. The results therefore support agroforestry as the most sustainable land use system, compared to cassava cultivation or pasture.

Eggplant (Solanum melongena L.) is one of the vegetables that has gained prominence in production in recent years due to the demand for foods with nutraceutical properties. However, few studies have been developed evaluating the effects of the use of organic residues in the fertilization of this crop, with the potential to both increase its productivity and reduce environmental impacts. Thus, this work aimed to evaluate the effect of organic fertilization with cattle manure and pasture on the productivity of eggplant cv. Cica. The experimental design adopted was in randomized blocks, with 4 treatments and 5 replications. The treatments consisted of 4 types of fertilization: T1, without fertilization (control); T2, bovine manure (20 t ha-1); T3, incorporated mulcher (8 t ha-1); and T4, mineral fertilization. There was a significant effect (p

The bulk density values indicative of compaction in clayey soils correspond to a wide range of values (1.30-1.47 Mg m-3), due to the diverse types of soil management. Our hypothesis is that if we consider bulk density values within similar management groups (those that fall to the ground and those that do not fall), the values will be more accurate within each management group. Our objective in this work was to analyze using the concepts of (Yates & Cochran, 1938; Whitehead, 2002) what is a suitable statistical way of grouping these results to reach a consensus regarding a tested hypothesis, the greatest number of density values surveyed between 1977 and 2021, considered for the study of compaction in clayey Oxisols under different managements, to verify whether our hypothesis will be confirmed. We selected 1,521 studies with bulk densities in the literature, corresponding to 44 years (1977 and 2021), which were analyzed by a statistical technique that integrates the results of two or more independent studies on the same subject and combines them into a summary measure (portion forestry). From the data collected in the literature, it was possible to separate two groups of bulk density and management in clayey soils indicative of compaction: the managements that perform little or no manipulation of the soil, such as pasture and no-tillage, densities between 1.41-1.45 Mg.m-3 (average 1.43 Mg m-3), and for the others, such as conventional plowing and minimum tillage, soil densities between 1.31-1.38 Mg.m-3 (average 1.35 Mg m-3). Finally, we conclude that compaction must be analyzed considering the texture and type of soil management.

In southern Brazil, together with Argentina and Uruguay, is located the Pampa Biome. The fungal diversity present in this place can be affected by soil exploitation, which end up, consequently, influencing other biological communities. The objective of this study was to compare the fungal diversity in different land use areas in the Pampa Biome. For that, soil collections were carried out in the city of Pantano Grande, located in Rio Grande do Sul. Three different land use areas were sampled: native, pasture and forestry areas. Soil fungi were isolated using the decimal dilution technique. Identification occurred through observations of macro and microscopic characteristics. Through statistics methods, the diversity of fungi was analyzed and the fungal community was compared between the sampled areas. A total of 265 individuals distributed in nine taxonomic types were isolated. The three areas had four taxa in common (Aspergillus niger, Aspergillus sp., Trichoderma sp. and Fusarium sp.), while the areas used for pasture were the only ones to present exclusivity in the presence of a taxon (Verticillium sp.). With this, it was possible to conclude that the areas used for pasture have the highest fungal biodiversity among the studied areas; however, statistically, the fungal richness between the different types of land use did not present differences. [ABSTRACT FROM AUTHOR]

Grasslands in southern Brazil have inherent characteristics favorable to forage production for domestic herbivores, which can be impaired or enhanced by management. The aim of this study was to evaluate the influence of management on plant characteristics, comparing commonly used techniques. The experimental design was bifactorial, the first factor consisting of four managements: burning, oversowing with annual winter forages, mowing and absence of interference, and the second factor was the time elapsed between management and evaluation. The experiment was conducted under field conditions, in a complete randomized block design with four replications. The LAI (leaf area index), dry mass production and crude protein content of the pasture were evaluated. Pasture management with oversowing showed higher LAI growth rate, as well as higher pasture dry mass production than the other treatments. There was no effect of the different managements on the crude protein content of the pasture, but of the time, with the highest value on the 53rd day. The results suggest that the adoption of management with oversowing of annual winter forages should be emphasized for the productive improvement of native grasslands in southern Brazil.

ABSTRACT: Listeriosis is an infectious disease caused by bacteria of the genus Listeria, the neurological form being more common in ruminants. There are many reports of listeriosis in small ruminants in the region that includes Brazil, Argentina and Uruguay. However, these diagnoses were mainly based on histological lesions in the central nervous system (CNS) without the isolation and characterization of the involved Listeria strains. The aim of this study was to report sheep and goats listeriosis cases from 2016 to 2021 in northwestern Uruguay. The diagnosis was made according to lesions observed at histopathology, plus Listeria isolation in CNS, identifying it at specie and serotype level. Nine animals (n=9) of three outbreaks and five sporadic cases of listeriosis were studied. Sheep was the species with more cases in relation to goats, and adults were the category most affected. Cases occurred in spring and less frequently in winter. All presented neurological clinical signs and the lesions in the CNS were consistent with suppurative meningoencephalitis and micro-abscesses in the brainstem. In eight of nine CNS samples, Listeria strains were isolated (seven L. monocytogenes and one L. innocua). All the L. monocytogenes isolates carried the inlA gene; serotyping showed that four strains belonged to serotype 1/2b, two isolates belonged to serotype 4b, and one to serotype 1/2a. Considering that listeriosis is a common disease in this region and the fact that isolates are scarcely recovered from small ruminants, it would be important to emphasize the need for Listeria isolation to better characterize the strains that affect animals. Not only to improve knowledge about the epidemiology of disease but also with the objective of developing serotype specific vaccines for animal use.

ABSTRACT This study examined the replacement of maize and soybean meal with cassava chips and alfalfa grazing, respectively. Twelve lactating Anglo-Nubian goats were kept on a Panicum maximum cv. Tobiatã pasture. The experiment was laid out in a Latin square design in which the following diets were tested: ground maize + soybean meal, cassava chips + soybean meal, ground maize + alfalfa grazing, and cassava chips + alfalfa grazing. The evaluated variables were feed intake, daily weight gain, milk yield and composition, and feeding behavior of the goats as well as production costs. Cassava chips and grazed alfalfa influenced the intakes of dry matter, crude protein, neutral detergent fiber, and total digestible nutrients. However, milk yield, body weight, and body score did not change. There was no diet effect on the proportions of protein, solids-not-fat, somatic cell count, or urea nitrogen in the milk. Treatments influenced the levels of fat, lactose, and total solids in milk, with the highest fat levels achieved with diets containing alfalfa. Grazing, rumination, and idle times and time spent interacting with other goats were not influenced by diets. The evaluated feedstuffs improved feed efficiency and reduced production costs. Therefore, cassava chips and alfalfa can replace certain ingredients without impairing the production performance of goats, but rather improving the profit of the producer.

The use of rock dust in agriculture as a soil remineralizer can reduce costs with the use of fertilizers, being an excellent alternative for improving soil fertility, especially for agroecological agriculture. In this sense, the study aimed to carry out a systematic review of the literature on the use of rock dust as a soil remineralizer in order to optimize the performance of forage plants. For this, the literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. To identify the articles on the subject of "Application of rock stone in forage farming", searches were carried out in the SCIELO and EMBRAPA databases. After developing an established article search strategy, identification of inclusion and exclusion criteria, critical evaluation of the results, thirty articles were selected for study and refinement proposed in the work. As for the general characteristics, two publications dated from the year 2000 and another twelve articles were published in the last 5 years, and the others between 6 and 10 years or over 10 years. Most of the articles selected in the present study are written in English and 75% of them were from studies conducted in Brazil. It was observed that the literature is extensive regarding the use of rock dust in agriculture, however, when it comes to its application in the production and management of pasture intended for the production of forage to be harvested mainly by grazing, the articles are scarce. In the technical analysis of the articles, it was found that most of them present positive aspects of the application of rock dust in the cultivation of forage plants. More studies are needed to confirm this fact, since publication bias must be taken into account. [ABSTRACT FROM AUTHOR]

The modification of the landscape, the intense exploitation of natural resources through intensive agriculture and the advance of the agricultural frontier result in the homogenization of the landscape and alteration of soil physicochemical conditions. These soil alterations cause changes in the composition and diversity of edaphic arthropod communities that can be used as biomonitoring and diagnostic tools in local areas. The objective of the study was to evaluate the diversity of edaphic arthropods and their association to different physicochemical parameters (i.e., pH, real density, bulk density, %OC, %OM and gravimetric and volumetric humidity) in three soil uses (permanent crop, rotational crop and pasture) in the experimental farm Tunguavita Paipa - Boyacá. The plot sampling technique was used to obtain data on biological and physicochemical variables. Samples were taken in three soil uses, permanent crop, rotational crop and cattle ranch. The edaphic arthropods and physicochemical variables were determined in the soil laboratory of the Universidad Pedagógica y Tecnológica de Colombia. The highest diversity of edaphic arthropods (309 individuals) was recorded in the permanent crop plot, followed by the rotational crop plot, both with high average values of %OM (1.82 - 1.90) and %OC (1.05 - 1.10). The Oligochaeta, Diplopoda and Araneae group were the major contributors to the biological differentiation between land uses. The changes in the abundance of edaphic arthropods were related to % gravimetric humidity, %volumetric humidity, pH, %OM and %OC, while the values of real density and bulk density did not correlate to a great extent with the changes in abundance. These variations allow the differentiation of land uses in an intervention gradient.

ABSTRACT The objective of this study was to evaluate the effect of different protein sources on the performance of lamb ewes and their offspring supplemented in deferred pasture. The treatments were the different protein sources: soybean meal, cotton cake, babassu cake and coconut cake. The ewes were weighed and evaluated for their body condition score during the gestation, parturition and weaning phases. The lambs were weighed at birth and at weaning. The structural variables and chemical composition of the pasture were evaluated during the usage period. Grass height and forage mass were higher when the ewes were in the gestation and weaning stages. The leaf mass was not altered during the pasture usage with a mean value of 566.1kg ha-1 DM. The highest levels of crude protein in the leaf blade were observed during the parturition and weaning phases. The body weight of the ewes did not differ between the sources with averages 45.0, 39.9 and 36.6kg for the gestation, parturition and weaning phases, respectively. Weights at birth and at weaning had an effect from protein sources, with the highest values observed in the lambs of ewes who received soybean meal and babassu cake supplementation. The lambs of ewes supplemented with soybean had higher average daily gain and total gain. Babassu, coconut and cotton cakes can replace soybean meal in supplementation of ewes in deferred pasture.

The objective of this review was to approach the intensive pasture termination system (IPT) as a possible alternative for the development of beef cattle in the semiarid region. Pasture are still the cheapest and most practical way in livestock as a source of food for cattle. In semi-arid regions, seasonality causes forage productivity to be low, causing a nutritional deficit in the animals. Strategies and technologies are developed to promote alternatives that supply nutritional deficiencies with forms of supplementation. One of them, TIP, brings the concept of confinement to the pasture, bringing good results and low structural and operational cost.

This article analyzes a group of toponyms in Gata, in the province of Cáceres, which reflect the public ownership of the land named, mainly throughout the 15th and 16th centuries, when the town began to gain some importance because it belonged to the Military Order of Alcántara. From then on, the survival or disappearance of names has been subject to both linguistic and extra-linguistic conditions.

ABSTRACT Shade-tolerant forest species are among the most susceptible to habitat loss in agricultural mosaics, where a variety of croplands is connected to forests at different levels of anthropogenic disturbance. We aimed to evaluate the community similarity of shade-tolerant species among different land use types across agricultural mosaics with different levels of disturbance. The study was conducted in three municipalities in southern and southeastern Pará state, in eastern Amazonia. A multiple-community similarity measure based on the Horn similarity index was used to compare land use types and assess the resilience of shade-tolerant species towards forest loss and disturbance at the landscape level. High shade-tolerant species similarity was found between mature forest fragments that underwent different levels of disturbance in all three agricultural mosaics, but secondary forests had lower similarity with mature forest in the most fragmented and altered mosaic. Shade-tolerant species showed very low density in croplands, but the same group of species seemed to colonize agricultural fields of annual crops and clean pasture, as they showed high community similarity. Another group of species was present in invaded pastures, probably due to the effects of time since land abandonment after woody species colonization. Mixed tree plantations were more similar to mature and secondary forests than other types of croplands. Shade-tolerant species similarity was higher among land use types inserted in agricultural landscapes that maintained conserved forest fragments. Our results suggest that the conservation of mature forests and landscape connectivity are crucial to the maintenance of shade-tolerant species in agricultural mosaics.

Fragmentation is a consequence of anthropic actions that cause changes in land use and cover. Owing to the conversion of forest areas into agricultural use areas, riparian vegetation becomes susceptible to the effects of fragmentation. This generates changes that affect the structure and composition of vegetation in the forest remnants. Therefore, this study aimed to analyze the structure and floristic composition of riparian vegetation with 30 m in a fragmented matrix. Accordingly, adult vegetation (DBH ≥ 5 cm) and regeneration (height ≥ 10 cm, diameter

Due to the multifactorial interplay of the morphogenic, morphologic and agronomic characteristics of forage species, it is necessary to find management options that increase the production and utilization of the forage mass of grasses when submitted to different defoliation frequencies and nitrogen application levels The objective of this study was to assess the effects of two defoliation frequencies and two nitrogen levels applied in a single dose on the morphogenic and structural characteristics and forage production of Piatã grass (Brachiaria brizantha cv. Piatã) grown in the rainy season. The experiment was carried out in the agrostological field of the School of Veterinary Medicine and Zootechnics of Mato Grosso do Sul Federal University (UFMS), in Campo Grande, Mato Grosso do Sul, Brazil. The experimental area was composed of 12 plots measuring 18 m² each, planted with Brachiaria brizantha cv. Piatã (Syn. Urochloa brizantha cv. Piatã). The experimental design was completely randomized and the treatments consisted of two defoliation frequencies (with cutting intervals of 28 and 35 days) and two nitrogen levels (100 and 200 kg ha-1 of N, in the form of urea, in a single application ), with three repetitions per treatment. The results showed that for Piatã grass swards established in soil having good fertility, the recommended management strategy is to set the minimum cutting or grazing height at 20 cm, with an interval of 28 days when the grass reaches an approximate height of 30 cm. In swards established in the rainy season, to reduce the fractioning of the N dose, it should be applied in a single dose of up to 100 kg of N ha-1 immediately after the first cutting.

Brazilian cattle production is mainly conducted with the use of cultivated or native forages, which is considered one of the most efficient ways of production. In this sense, this study aimed to evaluate the production and water-use efficiency of Guinea grass under different associations between nitrogen and boron doses, as well as different regrowth cycles. The experiment field (22o42’14.6” S, 47o37’24.1” W, and 569 - m altitude) has a regional climate classified as Cwa, which stands for a humid subtropical climate. The experimental design was randomized blocks, with a 4×4×11 factorial arrangement consisting of boron (0, 0.181, and 0.363 kg ha-1 cycle-1) and nitrogen (22.7, 45.5, 68.2, and 90.9 kg ha-1 cycle-1) fertilizations, plus 11 regrowth cycles and 4 replications. The pasture of Mombaça “Guinea grass” (Megathyrsus Maximus Syn. Panicum Maximum) was irrigated by a sprinkler system. Unlike boron, nitrogen positively influenced forage production. The cycles had a strong influence on production, with winter cycles being the least productive compared to the others.

This study aimed to evaluate the effects of levels of concentrate supplement and dietary lipids on the nutritional characteristics, metabolic parameters, and performance of Nellore bulls grazing tropical pasture. Twenty-seven Nellore bulls were allotted to 2 × 2 completely randomized factorial design with two levels of supplementation and two levels of dietary lipids. The concentrate supplement was fed at 4 g kg-1 BW (low supplementation) and 8 g kg-1 BW (high supplementation), whereas the dietary lipid content was 28 g of ether extract (EE) g-1 on a dry matter basis (DM) (low-lipid diet) and 42 g EE kg-1 DM (high-lipid diet). There was no interaction between the level of concentrate supplement and dietary lipid content on all studied variables. High levels of supplementation led to shorter grazing time and reduced forage dry matter intake (DMF). On the other hand, the DM intake increased with increasing levels of concentrate supplement, with no significant effects on DM digestibility. The dietary lipid content did not affect forage and DM intakes. However, the digestibility of DM and neutral detergent fiber (NDF) were lowest in high-lipid diets. Bulls receiving high levels of supplementation had higher average daily gains than low-supplemented animals. Neither the amount of concentrate supplement nor the dietary lipid content affected the hot carcass yield and carcass weight. Carcass fat deposition was greater in bulls fed high-lipid diets than in animals receiving low-lipid diets. The effects of the level of concentrate supplement and dietary lipid content on the nutritional characteristics and performance of grazing beef cattle are independent. Concentrate supplementation at 8 g kg-1 BW increases cattle performance but decreases forage utilization. Diets containing 42 g EE kg-1 DM reduces the digestibility of dry matter and fiber fractions, but increases backfat thickness.

Abstract Bioindicator organisms, such as edaphic invertebrates, are constantly used to assess disturbance, as they exhibit responses such as reduced community and changes in diversity, affecting the local ecosystem. The aim of this study was to compare the impacts of disturbance on the edaphic invertebrate community in both a pasture area and a native forest area, during summer and winter. Samplings were conducted for nine days using pitfalls. Bray-Curtis analyses, NMDS, ANOSIM, and SIMPER were applied. There was difference in richness and diversity between areas and seasons. Native forest pitfalls had higher similarity in abundance and diversity in both seasons than pasture pitfalls. Specimens belonging to 20 orders were collected; of those, Collembola, Hymenoptera, Diptera, and Hemiptera had the highest number of individuals. Seasonal influence on the organisms was evident. The impact on edaphic invertebrate community located in the pasture area showed that native forest has higher complexity and structural stability.

Abstract: The objective of this work was to determine the nitrogen, phosphorus, and potassium released by N-fertilized Urochloa brizantha straw, desiccated before sowing of no-tillage soybean (Glycine max) in succession. The pasture was grown in three paddocks, each fertilized with one N rate (0, 150, or 300 kg ha-1), and assessed at two desiccation periods (60 or 15 days before soybean sowing), in four replicates. Nitrogen fertilization of U. brizantha pasture increases N and K cycling and the release of these nutrients to the subsequent soybean crop. The quantity of K released by U. brizantha straw fertilized with 150 or 300 kg ha-1 N (about 80 kg ha-1 K) offsets that contained in an export of up to 4 Mg ha-1 soybean grains, assuming zero K losses in the system. An early desiccation of the U. brizantha pasture does not improve K uptake by the soybean crop, since 50% of the nutrient is released in the first 20 days after desiccation. The dynamics of P release from U. brizantha straw (about 6 to 10 kg ha-1 during the soybean crop) is not influenced by N fertilization and the time of pasture desiccation.

ABSTRACT: The objective of the study was to evaluate the efficiency of herbicides use in the control of tough lovegrass according to the availability of solar radiation and the presence or absence of flooded. Two experiments were conducted in a completely randomized design, in a 2x2x4 and 2x2x5 factorial scheme, where factor A was equivalent to the environment (natural or reduced radiation); factor B to water condition (with a 2 cm flooded or without); and, factor C the herbicides: cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), cyhalofop butyl + glyphosate (315 g ha-1 + 1080 g ha-1) and control (without application) in the first experiment. In the second experiment, the herbicides used were cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), sethoxydim (184g ha-1), imazethapyr (106 g ha-1) and control (without application). Glyphosate efficiently controls plants of tough lovegrass with four tillers (>90%), being superior to cyhalofop, imazethapyr and sethoxydim; independently, of resource conditions. Reduction in the availability of solar radiation generates less shoot dry mass production from the weed, and improves the control only by imazethapyr and cyhalofop. In general, a flooded condition does not affect tough lovegrass control by herbicides.

ABSTRACT The aim of this study was to evaluate the effects of homeopathic additives and the non-ionophore antibiotic virginiamicin® on intake, digestibility, metabolic characteristics and carcase characteristics in Nellore bulls under supplemented grazing. Twelve uncastrated Nellore bulls were used, with an initial mean weight of 346.04 ± 13.33 kg and initial age of 20.00 ± 2.00 months. The animals were kept in individual paddocks of Urochloa decumbens Stapf. (syn. Brachiaria) and divided into two treatments: Lipomax® - supplement concentrate with homeopathic additives (Convert H®, Sodo 100®, Figotonus®) and a non-ionophore antibiotic (Virginiamycin®); Control - supplement concentrate containing the same protein content, but with no additives. The experiment was carried out in a completely randomised design. Intake, the apparent digestibility of the dietary constituents and the metabolic characteristics of the bulls were not affected by supplementation with additives (P>0.05). Lipomax® improved weight gain in the animals (P0.05). Supplementation with homeopathic additives and virginiamicina® had a positive effect on performance and on hot and cold carcase weight in grazing Nellore bulls.

Urea coated with copper and boron may be a vehicle for selenium fertilization in grazing systems to improve both forage and animal productivity, and consequently, the nutritional quality of milk and meat. Urea is the most often used form of N fertilizer in Brazil; however, it can experience high losses by volatilization, primarily in pastures with high amounts of senescent biomass. The goal of this study was to evaluate losses by ammonia volatilization from urea coated with Cu, B, and Se. The fertilizer was applied to the soil surface under forage straw residues in cylindric glass chambers under controlled laboratory conditions. The treatments were urea (UR), urea coated with boric acid and copper sulfate (UBC), urea coated with boric acid, copper sulfate, and selenium (UBCS), and ammonium sulfate (AS). Measurements were recorded at regular intervals after fertilizer application for 27 days. High losses occurred from ammonia volatilization of amidic-N sources in the initial days after fertilizer application. The total loss of N by ammonia volatilization according to fertilizer treatment was UR > UBC = UBCS > AS. Urea lost by ammonia volatilization accounted for up to 50% of the N applied, although losses from coated urea treatments UBC and UBCS were 11.45% lower than that of urea. The Cu and B in the coated urea reduced losses by ammonia volatilization and the inclusion of Se had no effect. It is suggested that Se may be added to the Cu and B coating of urea to reduce ammonia volatilization.

Plant-growth-promoting bacteria can be used for sustainable forage grass production while increasing nutrition and biomass. Most of the soils under pasture in the tropics have a degradation level that impairs the forage yield potential, especially because of mismanagement and lack of fertilization. The objective of this work was to evaluate the seed inoculation effects of Azospirillum brasilense on the shoot and root dry mass production and nutritional status of Urochloa brizantha cv. ‘Marandu’ under field conditions for two years in a low-fertility soil. The experimental design was a randomized block design with four replications, arranged in a 2 × 3 factorial scheme, comprised of two doses of A. brasilense (0 and 200 mL ha-1) in combination with three doses of N (0, 25 and 50 kg ha-1). Seed inoculation increased shoot dry mass by 13% in the first year and by 6% in the second year, whereas N application increased dry mass by 27% and 35% in the first and second year, respectively. The concentration of nutrients in the shoots did not change due to the inoculation, but N fertilization affected P, Mg, Fe, Mn, and Zn in the first year and N, P and Cu in the second year. Root dry mass increased 36% with fertilization of 25 kg N ha-1 plus inoculation in relation to the other treatments in the first year. In the second year, the inoculation of A. brasilense increased by 17%. Therefore, seed inoculation of Urochloa brizantha cv. ‘Marandu’ with Azospirillum brasilense increased root and shoot dry mass production in some cuts without influencing tiller numbers. Nitrogen fertilization altered N, Mg, P, Fe, Mn, Zn, and Cu concentrations in shoot dry mass.

ABSTRACT The study of cultivars with moderate flood tolerance is essential to their use in pastures irrigated with saline water. The aim of this study was to evaluate the chemical composition of Panicum maximum ‘BRS Zuri’ under the effect of different irrigation depths and levels of salinity. A randomised block design of split plots was used with five replications per treatment. The treatments resulted from the combination of three levels of water salinity (S1 = 0.6, S2 = 1.8 and S3 = 3.0 dS m-1) and four levels of irrigation (I1 = 60%, I2 = 80%, I3 = 100% and I4 = 120% of the evapotranspiration). The chemical composition of the grass, Panicum maximum ‘BRS Zuri’, cut at 28 days, was evaluated over two cycles. There was an interaction between the factors (salinity x irrigation depth x cycle) for the dry matter (DM) content. With the increase in irrigation depth, there was a linear reduction in the crude protein (CP) content in both cycles. The neutral detergent fibre (NDF) and cellulose (CEL) content increased linearly as a function of the irrigation depth, while the lignin (LIG) content decreased linearly with irrigation depth. It was concluded that high levels of salinity cause reductions in the dry matter content in response to increased water availability and extension of the cultivar cycles. The reduction in saline levels under low water availability results in a higher CP content. Salinity has a negative effect on the NDF, ADF, HEM, CEL and LIG content as the irrigation depth increases.

Copyright of Revista IRRIGA - Brazilian Journal of Irrigation & Drainage is the property of Revista IRRIGA (Brazilian Journal of Irrigation & Drainage) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista IRRIGA - Brazilian Journal of Irrigation & Drainage is the property of Revista IRRIGA (Brazilian Journal of Irrigation & Drainage) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista IRRIGA - Brazilian Journal of Irrigation & Drainage is the property of Revista IRRIGA (Brazilian Journal of Irrigation & Drainage) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to manage native forest species, it is necessary to know both the characteristics and dynamics of the trees over time, as well as their morphometric relationship to improve silvicultural techniques. The aim of this study was to evaluate the morphometric characteristics of solitary Brazil nut trees (Bertholletia excelsa H.B.K), in the towns of São João da Baliza and Caroebe, in the State of Roraima. The inventory evaluated 49 individuals with a diameter at breast height (DAP) ≥10 cm. The following morphometric variables were evaluated: diameter at breast height, measured 1.30 m from ground level; total height (HT), commercial trunk height (HC); crown diameter (DC), crown length (CC), crown ratio (PC), crown area (AC), degree of slenderness (GE), salience index (s), crown cover index (ia) and crown shape index (fc). To study interdimensional relationships, the morphometric variables were related to the DAP using regression analysis. It was found that 32.9% of individuals presented a mean value for ht of 16.05 m and a DAP of 49.75 cm, with values for ac, cc and pc of 12.61 m2 , 8.18 m and 51.29 m respectively. The results showed a statistically significant relationship between DAP and HT, CC, PC, IS, FC and AC. The length, crown ratio and crown diameter showed a wide range of variation. The crown shape revealed that Brazil nut trees have crowns that are more elongated. It is possible to fit the significant mathematical models as a function of DAP. More-efficient measures are needed to ensure the full protection of these isolated individuals. = Para manejar espécies florestais nativas, é necessário conhecer tanto as características quanto a dinâmica das árvores ao longo do tempo, bem como suas relações morfométricas a fim de aperfeiçoar as técnicas silviculturais. Assim, objetivou-se com o presente trabalho avaliar as características morfométricas de árvores solitárias de castanheira-do-brasil (Bertholletia excelsa H.B.K), nos municípios de São João da Baliza e Caroebe, RR. O inventário avaliou 49 indivíduos com diâmetro a altura do peito (dap) ≥10 cm. Foram avaliadas as seguintes variáveis morfométricas: diâmetro à altura do peito, tomado a 1,30 m a partir do nível do solo; altura total (ht), altura comercial do fuste (hc), diâmetro de copa (dc), comprimento de copa (cc), proporção de copa (pc), área de copa (ac), grau de esbeltez (ge), índice de saliência (is), índice de abrangência (ia) e formal de copa (fc). Para o estudo das relações interdimensionais, as variáveis morfométricas foram relacionadas com o dap, mediante análise de regressão. Foi observado que 32,9% dos indivíduos apresentaram ht média de 16,05 m e dap de 49,75 cm; com ac, cc e pc de 12,61 m², 8,18 m e 51,29 m, respectivamente. Os resultados mostraram relações estatísticas significativas entre o dap e as variáveis ht, cc, pc, is, fc e ac. O comprimento, a proporção de copa e o diâmetro de copa apresentaram grande faixa de variação. O formal de copa revelou que as castanheira-do-brasil apresentam copas mais alongadas. É possível ajustar modelos matemáticos significativos em função do dap. São necessárias medidas mais eficientes para garantir a proteção integral desses indivíduos isolados.

Goal was to evaluate the effect of mineral and/or energy-protein supplementation on intake, behavior, production response, pH, rumen ammonia and production cost of sheep. Twenty female lambs and five rumen-cannulated lambs were used to test supplementation effects on weight gain and nutritional characteristics, respectively. Treatments evaluated were: mineral mixture, supplement with 20 and 25% of crude protein offered at 0.5 and 1.0% of body weight. Supplementation at 1.0% of body weight reduced forage intake. Average daily gain were: -58.33, -1.07, -9.53, 19.27 and 34.73 g day-1 per animal, for mineral mixture, supplements with 20 and 25% of crude protein supplied at 0.5% of body weight and 20 and 25% crude protein provided at 1.0% of body weight, respectively. Rumen pH for all supplements was maintained above 6.20. Values of rumen ammonia nitrogen were 5.10, 9.48, 11.54, 17.51 and 22.45 mg dL-1 for supplements: mineral mixture, 20 and 25% of crude protein provided at 0.5% of body weight and 20 and 25% of crude protein supplied at 1.0% of body weight, respectively. The best economic return was obtained with the supplement 25% of crude protein provided at 1.0% of body weight.

ABSTRACT: The aim of this study was to evaluate the oxidative and anti-oxidative status of unaged and aged Longissimus dorsi (LD) muscle obtained from a commercial abattoir. Also, fatty acid composition and calculated health lipid indices of meat were compared. Animals slaughtered were Aberdeen Angus steers raised in three typical feeding systems of Uruguay: (1) Pasture (n=10), (2) Pasture + Supplement (P+S) with corn grain (n=10), and (3) Feedlot (n=10). Feeding had no effect on lipid and protein oxidation but the antioxidant enzymes activities were affected as follows: superoxide dismutase (SOD): Pasture, Feedlot > P+S; catalase: Pasture > P+S, Feedlot; glutathione peroxidase (GPx): Feedlot > P+S > Pasture. Total antioxidant potential, determined by Fenton reaction, was higher in aged meat from Pasture compared with aged meat from Feedlot. Meat from Pasture and P+S presented a higher eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and total n-3 content and a lower lipid content, n-6/n-3 ratio and trombogenic index compared to meat from Feedlot. In conclusion, Pasture seems to produce a more resistant meat against induced oxidation processes, particularly after ageing, and a healthier meat together with meat from P+S system, regarding fatty acid composition and lipid indices, compared to Feedlot.

ABSTRACT The objective was to evaluate the effect of three stocking rates (2, 3.9, and 5.8 animal units ha−1) and three fertilization levels (0, 150, and 300 kg N ha−1 yr−1) on herbage mass and nutritive value of elephantgrass (Pennisetum purpureum Schum.) cv. IRI-381. The experiment was conducted from May to August of 2009 and 2010 in Itambé, PE, Brazil, during the rainy season. Treatments were allocated in a split-plot arrangement in a completely randomized block design. The variables measured included leaf mass (pre- and post-grazing), botanical composition, soil cover, leaf area index, light interception, leaf angle, and concentrations of dry matter, organic matter, N, and in vitro digestible dry matter. When fertilized with 300 kg N ha−1 yr−1, leaf mass reached 18,560 kg ha−1. Leaf area index decreased with increasing stocking rate. The relationship between sward height and light interception was R2 = 0.0126. Increased stocking rate resulted in greater contribution of signalgrass [Brachiaria decumbens (Stapf.) R.D. Webster] in the botanical composition, with a contribution up to 29% in 2010. Elephantgrass nutritive value is directly affected by the fertilization levels and stocking rate, with highest nutrient concentrations observed with 2 AU ha−1 and 300 kg N ha−1 yr−1.

The objective of the present study was to evaluate whether cow's milk produced in different systems (confinement or pasture) when consumed interferes in blood parameters and intestinal health, as well as the importance of daily milk consumption in the individual growth, an animal model. For this purpose, in natura milk from two farms with different breeding systems (Free Stall - pasture) was compared to pasteurized milk (UHT), used as control. The centesimal composition of the milks was analyzed, separated into aliquots and then frozen. 28 rats were used as experimental models (animal model) for a period of 30 days, divided into four groups with seven animals each: milk from cows raised in the Free Stall system (GFS), milk from cows raised in the pasture (GP) system, pasteurized cow's milk (GUHT), and non-dairy animals (CG). Volume of 0.7 mL of milk was offered daily. When compared to the control group (GC) we observed a difference (P <0.05) for the following variables in serum and groups: higher protein levels - GUHT and GP; higher albumin levels - GP and GFS; higher globulin levels - GUHT; higher urea levels - GUHT, GP and GFS; lower glucose levels - GP; higher triglyceride levels in the groups that received milk - GP, GFS and GUHT; and higher cholesterol levels - GP. The villus size did not differ between the groups (P> 0.05), however, the crypt size was higher in the GP and GFS groups (P <0.05). The animals that received milk had greater weight gain (P <0.05) compared to CG. Thus, we conclude that the supply of milk with different compositions affects distinct blood variables, which stimulated crypt enhancement and weight gain. [ABSTRACT FROM AUTHOR]

The species of the genus Urochloa has been highlighted in the crop-livestock integration and practices such as the type of seed used, and the depth of sowing are fundamental for the establishment and production of the pasture. The objective of this research was to evaluate the emergence and growth of plants of Urochloa brizantha cv. Marandu, originating from seeds incrusted or not, sown in different depths and soils. The experimental design was a randomized block design with four replications. The treatments were arranged in a 2x5 factorial scheme, composed of two types of seeds (incrusted or not) seeded in five depths (0; 1; 2.5; 5; 10cm) in medium textured and clayey soils. Plants of U. brizantha from seeds incrusted and cultivated in medium textured soil presented higher emergence, but lower growth in relation to the plants coming from non-incrusted seeds. In soils of clayey texture, the use of incrusted seeds promoted a greater speed of emergency, but less growth of the plants. The sowing of U. brizantha at 1.0 and 2.5 cm depth provided a higher emergence speed, regardless of soil texture and type of seed. After forage cutting, the greatest tillering of regrowth was observed in plants from non-encrusted seeds and sown in soil up to 2.5 cm deep. At regrowth, there was no effect of treatments on forage yield. [ABSTRACT FROM AUTHOR]

We aim to evaluate physical characteristics that, when submitted to agricultural use, can promote the formation and development of linear erosion processes. To do so, we selected a subbasin with intense erosion activity located at the western region of the state of São Paulo, Brazil. In this area, we mapped linear erosion features, such as furrows, ravines, and badlands, in the years 1963, 1997, and 2016 and also the variables lithology, landforms, slope, and land use. Subsequently, we analyzed the distribution of erosion forms in the variables in the three years. As a result, with the extensive and continuous use of pasture for at least five decades, we verified that erosion has been more active on silty-clay lithologies, slopes of 15-47% and =47%, and on concave slopes, reaching lands with other characteristics through regressive erosion and the edge effect. Slope concaves comprised ravines and mostly badlands, and served as connectors between erosion processes that occur in higher areas and those occurring in sectors of lower altitude. [ABSTRACT FROM AUTHOR]

Copyright of Investigación Agraria is the property of Investigacion Agraria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aimed to evaluate the control and susceptibility of signalgrass and ruzigrass in initial growth under different rates of glyphosate and fluazifop-p-butil. The treatments were distributed in a 2 × 6 factorial design, with five repetitions, being two grasses: Brachiaria decumbens cv. Basilisk (signalgrass) and B. ruziziensis (ruzigrass) with six doses of herbicides: 0.00; 0.25; 0.50; 1.00; 1.5 and 2.00 times the commercial dose recommended by manufacturers. At 7, 15, 21, and 30 days after herbicide application (DAA) were evaluated the intoxication in signalgrass and ruzigrass, visually. The glyphosate toxicity was of 100% in both plants, signalgrass and ruzigrass, even at the lowest dose (90 g ha-1), so it can control effectively these species in early growth stage. It was observed that the plants exposed to fluazifop-p-butil showed regrowth only in the doses to 100 g ha-1 and 50 g ha-1 for signalgrass and ruzigrass, respectively. These results confirm the effectiveness of this herbicide molecule in the control of these two species from doses of 200 g ha-1 and 100 g ha-1 for signal grass and ruzigrass, respectively. [ABSTRACT FROM AUTHOR]

Abstract The objective of this work was to evaluate the effect of soil carbon on landscape functioning of the Oxisols covering the plateaus of the Alto São Bartolomeu watershed, in the Cerrado (Brazilian savanna) region of Central Brazil. Soil organic carbon (SOC) concentration, carbon stocks, and some soil physical and chemical characteristics were determined at the 0-0.20-m depth on native and anthropogenic areas. Soils from cerrado stricto sensu patches were similar both physically and chemically, being affected by exchangeable Al3+ and by SOC concentrations, while anthropogenic matrices were affected by soil bulk density, pH, extractable P, and exchangeable Ca2+ and Mg2+. The estimate of spatial distribution of soil carbon better fitted had an adjusted R2 of 64.49% using soil C stock and 66.50% using SOC concentration from native and anthropic areas. Estimating SOC concentration from soil and landscape types, using geotechnologies to analyze vegetation indices, is a potential tool to evaluate the productivity of different agroecosystems, besides contributing to make management strategies more suitable on large scales.

The present study was conducted during the second semester of 2015 in livestock farms of five locations of the Department of Sucre, established with pastures colosuana (Bothrichloa pertusa (L) to. Camus), angleton (Dichanthium aristatum, Benth) and mombaza (Panicum maximum Jacq), with the objective of evaluate colonization of mycorrhizal arbuscular fungi (AMF) in roots of these pastures. Sampling was done randomly in each livestock farm, gathering at the same time samples of soil and roots, which were used for the determination of the infection percentage using technique of staining of roots by AMF. Results show that the infection percentages were 52,73% in the colosoana pasture and 50,46% for angleton, being statistically similar; while mombasa grass had less colonization 40,92%. The highest value of AMF colonization corresponded by locality to Chapinero 70,06% and minors for Cantagallo 37.06% and Mamon 32.7%. The present study confirmed the presence of AMF in three species of pastures of economic interest for livestock farming in the Department of Sucre. Likewise, the colonization of’ roots AMF depended on the type of pasture and the locality.

Changes in land use have motivated research on the dynamics of radiative and energy exchange in the Brazilian Amazon, which in turn cause demand for such data on the surface in spatial and temporal scales. While measuring these changes in micrometeorological towers provides punctual results, remote sensing provides accurate and low cost results to estimate them on a regional scale. This study aimed to evaluate the spatial and temporal distribution of estimates of net radiation and biophysical parameters from remote sensing in different land uses in southwestern Brazilian Amazon. Four sites were selected with soil covers by natural Amazon forest, Amazon managed forest, pasture and silvopastoral system. The net radiation and biophysical parameters (NDVI, leaf area index, albedo and radiometric temperature) were estimated by the SEBAL algorithm, using images from the Landsat TM sensor 5 in July of 2009, 2010 and 2011. The NDVI, LAI, albedo and net radiation were higher in natural forest, followed by managed forest, grassland and silvopastoral system. Radiometric surface temperature were higher in the silvopastoral system followed by pasture, natural forest and managed forest.

This research had as objective to evaluate the performance of intact or castrated beef cattle in a croppasture rotation system. The experiment was conducted during 2004 and 2005, and carried out at the Cooperativa Agropecuária Mourãoense (COAMO) Experimental Farm, in Campo Mourão city, Paraná state. It was used a completely randomized design, with two treatments, intact or castrated. Forty ½Angus+½Nelore crossbred animals, with average age of nine months, were used. Half of the animals were castrated at weaning, and the other half was kept intact. Pasture was composed of two areas. The winter field, established after soybean crop, was composed by a mixture of black oat (Avena strigosa) and Italian ryegrass (Lolium multiforum). The summer field was composed by stargrass (Cynodon nlemfuensis) and Mombaça grass (Panicum maximum). During the winter time it was used a continues grazing system, with regulator animals (put and take), and during the summer an intensive rotational system, with regulator animals and fixed grazing period. Intact animals presented higher average daily weight gain (0.907 vs 0.698 kg), slaughter weight (490.9 vs 442.2 kg), and hot carcass weight (250.2 vs 232.6 kg). Slaughter age was influenced by sexual condition, being lesser in the intact animals. Carcass dressing percentage was similar for the groups. Castrated animals showed better finishing fat cover and backfat thickness (3.45 vs 2.70 mm) compared to intact ones. Therefore, it can be concluded that intact animals presents better performance than castrated ones when finished in an intensive crop-pasture rotation system, however, they may not present the minimum required fat cover, when slaughter at young ages.

This experiment was conducted to study the substitution of soybean meal with peanut cake in the supplement by assessing the feeding behavior and the interaction between the thermal environment and the physiological responses of eight crossbred cows with an average live weight of 500 kg. Cows were divided into two 4 × 4 Latin squares and managed on pasture. The peanut cake was included at the levels of 0, 330, 660, and 1,000 g kg-1 in the supplement as a replacement for soybean meal. The feeding behavior variables were not affected by the levels of peanut cake. No differences were found for the physiological parameters of the animals with the replacement of soybean meal for peanut cake in the supplements. Peanut cake can replace up to 100% soybean meal in the supplement of grazing lactating crossbred cows without altering the feeding behavior or physiological parameters of the animals.

The objective of this study was to evaluate the contribution of vegetative and reproductive tillers in the structure of marandu palisade grass (Urochloa brizantha syn Brachiaria brizantha cv. Marandu) with heights (15 and 30 cm) and nitrogen doses (0, 40, 80 and 120 kg ha-1 of N) variables at the beginning of the deferment. The experimental design was completely randomized, with three replications, using the 2 x 4 factorial systems. There was a linear and positive response of the number of live tillers in the low pasture as a function of the nitrogen doses. The live tissue mass, the percentage of live stalk and the leaf area index in the low pasture increased linearly with the nitrogen doses. The percentage of live leaf blade decreased linearly with the application of nitrogen. The participation of the reproductive tiller in the masses of live leaf and live stem and in the leaf area index was lower in the low pasture when compared to the high one. The vegetative tillers have a major contribution in the structural characteristics of the deferred pastures of marandu palisade grass deferred for 80 days. The effects of nitrogen on the marandu palisade grass structure are higher in the low pasture than in the high pasture. To reconcile the amount of forage and grass structure, Urochloa brizantha syn Brachiaria brizantha cv. Marandu deferred in March in the Uberlândia region can be demoted to 15 cm and fertilized with 80 kg ha-1 of N. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the interrelationships between land use, landscape position (position in a toposequence) and its effects on physical, chemical and microbiological attributes in soils under different land use systems in two toposequences in Northwest of Rio de Janeiro State. The toposequence 1 consisted of spontaneous vegetation in the summit and pupunha palm plantation in the backslope and footslope; Toposequence 2 consisted of pasture in the three positions. The following variables were determined: bulk density, total porosity and clay content; P, Ca, Mg, K, Al content and pH; microbial biomass carbon and nitrogen, microbial respiration, organic C and total N. Tocher method and principal component analysis (PCA) were performed for different groups of variables. Initially the physical attributes and some chemical attributes and then the microbiological attributes, organic C and total N were used. The groups formed by the Tocher method for the two sets of variables used were confirmed by the PCA. The set of physical and chemical attributes were more sensitive than COS, Nt and microbiological attributes to explain the similarity and, or, dissimilarity due to both toposequence positions and vegetal cover conversion. The microbiological attributes, COS and Nt showed the influence of vegetal cover conversion and management practices (and, or absence) in the dissimilarity between land use systems. The relevance of physical, chemical and, or, microbiological attributes to distinguish land use systems will depend on the variation sources of the environments in which these systems are being studied. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of no-tillage systems with different input of straw and nitrogen before soybean crop to increase soybean yield. A field experiment was carried out in an experimental area of the University of Western São Paulo, College of Agricultural Sciences, in Presidente Prudente/SP, in a dystroferric red-yellow Argisol, between January 2014 and April 2016. A randomized complete block design was followed with four replications in a split plot where the plots consisted of (I) Maize/Lupine/Soybean, II) Maize + Urochloa brizantha/Soybean, III) Urochloa brizantha/Soybean and in the subplots four nitrogen doses (50, 100, 150 and 200 kg ha-1), applied annually. The amount of straw and its persistence on the soil before and after sowing of soybean and soybean yield in the two years of the experiment were analyzed. The results were submitted to analysis of variance and the effects of the variables were compared by Tukey test at the 5% probability level. The no-tillage systems influenced the amount of dry matter accumulated before and after soybean planting in the two evaluated years. The C/N ratio was influenced by interaction between M+U and 200 kg ha-1 of N before soybean seeding. The amount of dry matter obtained by the interaction of Urochloa with 200 kg ha-1 of N at the time of grain harvest, showed that the rotations that used forage produced more straw and that the supply of the highest nitrogen fertilizer dose favored the productivity of the forage and the greater contribution of C to the system. Nitrogen fertilization distributed throughout the agricultural year has the potential to increase soybean yield in years without severe water restriction. [ABSTRACT FROM AUTHOR]

Copyright of Revista Acadêmica: Ciência Animal is the property of Revista Academica: Ciencia Animal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT This study was conducted in order to evaluate the selectivity of signal grass and congo grass, submitted to post-emergence herbicide application. The experiment was conducted under greenhouse conditions, in Diamantina, Minas Gerais state, and it was arranged in a randomized block design, with five replications. Treatments were set in factor scheme (8 x 2) + 2. Eight herbicides (nicosulfuron; clomazone; glyphosate; fluazifop-p-butyl + fomesafen; lactofen; fomesafen; fluazifop-p-butyl and mesotrione) were applied in doses recommended by the manufacturer on two fodder species: Brachiaria decumbens cv. Basilisk (signal grass) and Brachiaria ruziziensis (congo grass); in addition, there were two control samples without herbicide application, for a total of 18 treatments. The evaluated herbicides showed less intoxication on signal grass when compared to congo grass. Nicosulfuron and glyphosate promoted higher intoxication on both species when compared to the other herbicides. Glyphosate, fluazifop-p-butyl + fomesafen, fluazifop-p-butyl, mesotrione and nicosulfuron affected the ratio variable / maximum fluorescence (Fv/Fm) in both species, indicating an effect provided by these herbicides on the electron transport chain. Results demonstrated that signal grass and congo grass have higher susceptibility to glyphosate, fluazifop-p-butyl + fomesafen, fluazifop-p-butyl, mesotrione and nicosulfuron. congo grass shows higher susceptibility to the studied herbicides when compared to signal grass.