Arachis Pintoi Cv Research Articles

Biochar and Forage Peanut improve pastures: Evidence from a field experiment in Brazil

Pasturelands, often degraded, represent most of the converted lands globally. It is important to understand how different pasture management approaches can improve soil quality, increase feed production and farmer income. Here, the impact of different soil enhancers on soil quality and productivity of three cultivars of Brachiaria (Syn. Urochloa) forage grass is presented. Soil enhancers included: biochar - a carbon-rich product from biomass pyrolysis, moinha (local charcoal residue), traditional fertiliser containing nitrogen, phosphorus and potassium, lime, and forage peanut (Arachis pintoi cv. Amarillo). Considering the total biomass produced over the experiment (sum of four harvests), the highest dry biomass production was observed for Brachiaria brizantha cv. Piatã (14.1 Mg ha−1) and cv. Marandu (12.7 Mg ha−1), for biochar application of 30 Mg ha−1. Paiaguás had the highest dry matter production (12.4 Mg ha−1) for the treatment with forage peanut plus 15 Mg ha−1 of biochar. The increases in dry mass production translated to additional income, as compared with the control, of U$ 1 291, U$ 1 183 and U$ 991 per year for Marandu, Piatã and Paiaguás, respectively. The increases in forage grass productivity were reflected by positive changes in soil characteristics such as improvement in cation exchange capacity, pH and nutrient contents. Improved management of tropical pasturelands holds opportunity for more sustainable food production, and for ecosystem services protection and recuperation, for example, biodiversity net-gain, water regulation and carbon sequestration.

Silagens mistas de cana-de-açúcar e amendoim forrageiro tratadas com Lactobacillus buchneri

Abstract There is evidence for the beneficial effects of forage peanut on the nutritive value and fermentation profile of silages; however, its effects on sugarcane silage have not been determined. The objective of the study was to evaluate the chemical composition, fermentation profile, microbial composition, and dry matter recovery (DMR) of sugarcane silage containing various amounts of forage peanut (Arachis pintoi cv. Belmonte) (0%, 25%, 50%, and 75% on a fresh matter basis), treated or untreated with Lactobacillus buchneri. A completely randomized 4 × 2 factorial design was used with three replications. The interaction between forage peanut levels and inoculant influenced the concentrations of dry matter, crude protein, neutral detergent fiber and acid detergent fiber, organic acids and ethanol, populations of lactic acid bacteria and yeast, gas and effluent losses, and DMR. Forage peanut levels had effects on dry matter, hemicellulose, acid detergent insoluble nitrogen, pH, and ammonia nitrogen. Increasing proportions of forage peanut increased the protein content and decreased the fiber content in the silage, while also reducing the production of ethanol and effluent. We recommend the inclusion of 40%–75% forage peanut in the sugarcane ensilage to improve the chemical composition and fermentation profile. Furthermore, inoculation with L. buchneri associated with forage peanut increases the concentration of antifungal acids in the silage and decreases the yeast population and ethanol production.

Chemical composition, fermentation profile, microbial population and dry matter recovery of silages from mixtures of palisade grass and forage peanut

The study evaluated chemical composition, fermentation profile, microbial population and dry matter recovery of silages made from mixtures of palisade grass (Urochloa brizantha cv. Marandu) and forage peanut (Arachis pintoi cv. Belmonte). The experiment was conducted and analyzed in a complete randomized factorial design using 5 levels of each forage (0, 25, 50, 75 and 100% on a fresh matter basis), with and without microbial inoculant and 3 replications. The crude protein concentration increased linearly (P<0.05) and fiber concentration decreased linearly (P<0.05) as forage peanut level in silage increased. There was a positive quadratic effect (without inoculant) and positive linear effect (with inoculant) on lactic acid concentration (P<0.05) and a positive quadratic effect (P<0.05) on lactic acid bacteria population with increasing forage peanut levels in silage. The main effects of the addition of forage peanut to palisade grass at ensiling were improvement in the chemical composition and fermentation profile of the grass silage. We recommend adding 25–75% forage peanut to palisade grass prior to ensiling to improve the quality of the resulting silage but there is little merit in adding microbial inoculant to the forage at ensiling. Feeding studies with animals would verify potential benefits in production from inclusion of legume with grass at ensiling, while studies with addition of energy sources at ensiling would determine any further benefits to be achieved in silage quality.

Nitrogen fertilizer increased litter deposition and litter N in warm-climate grasslands

In warm-climate grasslands, litter deposition and decomposition are one of the main pathway of nutrient cycling. The application of nitrogen (N) fertilizer or the inclusion of a legume in such grasslands modifies litter characteristics and chemical composition. This study evaluated how the N supply of palisadegrass [Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster] pastures affect litter characteristics two years after seeding. Treatments were palisadegrass fertilized or not with N (150 or 0 kg N ha???1 year???1) or mixed with the legume forage peanut (Arachis pintoi cv. Amarillo). The experimental period covered two consecutive rainy seasons. Nitrogen fertilization increased by 43 and 62% the existing litter mass (organic matter, OM), and by 32 and 23% the litter deposition rate compared to unfertilized palisadegrass or legume-grass mixtures, respectively. Both variables were affected by grazing cycle (GC), with low litter deposition rate (14 kg ha???1 d???1 OM) and existing litter mass (1390 kg ha???1 OM) in the GC4 due to low rainfall. Nitrogen fertilized palisadegrass had greater litter N concentration (7.9????????0.4 g kg???1 OM???C:N ratio 34????????2) than in monoculture or legume-grass mixtures (C:N ratios 45 and 58????????2, respectively). Our results indicated that N fertilization of palisadegrass increased litter accumulation, however, N fertilization was not a key driver of the litter decomposition rate, even though it increased litter N concentration. After 2 years of establishment, the proportion of forage peanut in the litter was still low, reducing the benefits of legume inclusion to enhance litter nutrient cycling in these pastures.

Measurement of Nutritive Value and Phenolic Compounds in Forage Plants Used in Animal Production

Secondary metabolites are important organic metabolites produced by plants. These metabolites include phenolic compounds, which have been of research interest because phenolics are considered an antinutritional factor for ruminants, compromise the bioavailability of nutrients. This study included a chemical composition analysis, an analysis of the condensed tannin content and the identification and quantification of the phenolic compounds present in the following plants cultivated with and without fertilisation: Coastcross-1 grass (G) and the legumes Stylosanthes guianensis cv. Mineirão (MS), Stylosanthes capitata × Stylosanthes macrocephala cv. Campo Grande (CGS), Arachis pintoi cv. Amarillo (AA) and Arachis pintoi cv. Belmonte (AB). High-performance liquid chromatography (HPLC) was used to analyse 13 phenolic compounds. The forage with the best nutritive value was Amarillo pinto peanut. The condensed tannin content was higher in the legumes than that in the grass. Vanillin and o-coumaric, m-coumaric, caffeic and ferulic acid were detected in all the cultivars. The cultivar with the largest variety of phenolic compounds was Coastcross-1 grass. Diversity existed in the occurrence of phenolic compounds, which indicated the presence of condensed tannins in the cultivars and possibly that the diversity does not affect the concentration of these compounds. The AA cultivar was the most interesting alternative for the establishment of pasture intercropped with Coastcross-1 grass.

Soil management and planting spacing effects on establishment of mixed swards of purple stargrass (Cynodon nlemfuensis cv. BRS Lua) and forage peanut (Arachis pintoi cv. Belmonte) in an area of degraded Brachiaria brizantha

The aim of this study was to assess the effect of soil management and planting spacing on establishment performance of mixed swards of purple stargrass ( Cynodon nlemfuensis cv. BRS Lua) and forage peanut ( Arachis pintoi cv. Belmonte). The treatments comprised two methods of soil management (conventional tillage, with desiccation followed by harrowing; and no-tillage, with sequential desiccation with glyphosate) and two planting spacing (50 and 100 cm between rows) that were arranged in a split-plot design. Both methods of soil management ensured rapid pasture establishment, with canopy cover greater than 94% at 84 days after planting, with the NT surpassing the CT, and at a cost of NT 7% lower. Reducing planting spacing from 100 cm to 50 cm accelerated canopy cover and reduced weed incidence. No-tillage was as efficient in establishing mixed swards as conventional tillage.

Production of beef cattle grazing on Brachiaria brizantha (Marandu grass)—Arachis pintoi (forage peanut cv. Belomonte) mixtures exceeded that on grass monocultures fertilized with 120 kg N/ha

AbstractMixed grass/legume pastures are an alternative to grass monocultures for increased beef cattle production in tropical climates. The objective of this study was to evaluate the productivity of beef cattle grazing either a mixed pasture of Brachiaria brizantha cv. Marandu grass and Arachis pintoi (forage peanut) cv. Belomonte or a Marandu monoculture, under rotational stocking. Five trials were conducted over a period of nine years in north‐eastern Brazil where the sward structure (forage, grass and legume mass) and animal performance were compared for a mixed Marandu grass/forage peanut pasture, and a Marandu grass monoculture with 120 kg N ha−1 y−1. Stocking rate was adjusted to maintain forage allowance at 4% body weight/day. A block design was used with four replicates, and warm and cool seasons within each trial were considered, using repeated measurements over time. In the warm season, the forage mass in the mixed pastures was 17% greater than in the monoculture (p = .049), and the stocking rate, average daily gain and liveweight gain per ha were 16.4%, 20.0% and 28.7% greater (p = .004, p < .001 and p < .001 respectively). The average daily gain showed a positive linear relationship with the legume proportion in the sward (p < .001). The mixed forage peanut/Marandu pasture sustained significantly greater beef cattle production (789 kg ha−1 y−1) compared to the N‐fertilized grass monoculture (655 kg ha−1 y−1). Appropriately managed, mixed pastures of forage peanut/Brachiaria pastures are sustainable and have high potential for use in the humid tropics.

Grazing criteria for perennial peanut (Arachis pintoi cv. Amarillo) consumed by sheep in rotational stocking

ABSTRACT The objective of work was to study the productive profile of perennial peanut in a rotational stocking environment under different criteria. The treatments corresponded to pre-grazing height of 14 and 18cm or 95% of light interception (LI) distributed in a completely randomized design. The studied variables were forage mass, percentage of structural components, forage mass and the structural components in the lower and upper canopy strata. The entrance criterion of 18cm in height, despite having higher forage mass, presented lower percentage of leaves and higher percentage of stems and forage losses. The criteria of 14cm and 95% light interception presented similar production between them and the highest rate of forage accumulation. In all criteria, in the upper strata of pasture a higher percentage of leaves were found. The criteria of 95% LI and 14cm in height presented the best productive performances. The entry criterion of 18cm presented a higher mass of pre-grazing forage with lower percentage of dead material, but with higher forage losses, resulting from senescent leaves. Due to changes in the structural components, as grazing cycles increase, the interception of 95% of the incident light by the perennial peanut occurs at lower heights.

Nodulation and biological nitrogen fixation (BNF) in forage peanut (Arachis pintoi) cv. Belmonte subjected to grazing regimes

Productivity of grassland ecosystems is highly dependent on the availability of nitrogen (N) from the soil and/or biological fixation (BNF) from the atmosphere. However, the high cost of N-fertilizers and the increasing awareness of the need for sustainable nutrient alternative sources have increased the strategic importance of the BNF. Defoliation interferes with plant growth and also with BNF in legumes, since it modifies the leaf area and the availability of energy to plants. In spite of the potential advantages of forage legumes to pastures, current knowledge regarding the effects of grazing management on BNF is scarce. In order to evaluate the effect of grazing management on aerial and root mass, nodulation and BNF in forage peanut (Arachis pintoi cv. Belmonte), two experimental protocols based on the continuous and intermittent (rotational grazing) stocking methods were used. In the continuous stocking protocol, treatments corresponded to four grazing intensities represented by four management heights - 5, 10, 15 and 20 cm. In the intermittent stocking protocol, treatments corresponded to combinations between two pre- (95% and maximum canopy light interception during regrowth – LI95% and LIMax, respectively) and two post-grazing (post-grazing heights equivalent to 40 and 60% of the pre-grazing height) conditions. It was hypothesized that hard grazing, represented by low management heights under continuous stocking or low post-grazing heights under intermittent stocking, causes reduction in root mass and nodulation interfering with the balance between root and aerial, with negative impacts on BNF. Under continuous stocking, greater number of nodules was associated with lower nodule mass and vice-versa throughout the year. Swards managed at 5 and 10 cm had greater root and nodule mass than those managed at 15 and 20 cm. However, greater BNF (%Ndfa and BNF) was recorded on swards managed at 15 and 20 cm relative to those managed at 5 and 10 cm. Under intermittent stocking, the combinations between frequencies and severities of grazing did not affect root mass or nodule number at both pre- and post-grazing conditions. Overall, swards managed with the LIMax target showed greater BNF than those managed with the LI95% target. For swards managed with the same LI target (LI95% or LIMax), hard grazing (40% of the pre-grazing height) resulted in lower %Ndfa and BNF during early and late spring and summer II. For both grazing methods, the range of management targets used did not result in negative impacts on root mass or nodulation. Regardless of grazing method, BNF was determined by aerial biomass, indicating that moderate intensities of grazing would be adequate for optimizing BNF.

Amendoim forrageiro manejado com baixos resíduos de pastejo por ovinos

RESUMO O objetivo do trabalho foi estudar o comportamento produtivo do amendoim forrageiro (Arachis pintoi cv. Amarillo) sob diferentes intensidades de pastejo por ovinos em ambiente rotativo. Os tratamentos corresponderam a quatro intensidades de pastejo (muito leniente - ML, leniente - L, moderado - M e severo - S) representadas pelas alturas de resíduo de 11,2; 8,4; 5,9 e 3,2cm, que foram alocadas segundo um delineamento inteiramente ao acaso, com quatro repetições. As variáveis estudadas no pré e no pós-pastejo foram: massa de forragem, percentual de folhas e caules e índice de área foliar. Ao final do experimento, foi calculada a massa de forragem total acumulada, a taxa de acúmulo e a massa de forragem desaparecida. Os dados foram submetidos à análise de variância e ao teste de comparação de médias de Tukey (P< 0,05). Foi verificado que a intensidade de pastejo modifica a composição dos componentes morfológicos e a massa de forragem acumulada pelo amendoim forrageiro, todavia o índice de área foliar no pré-pastejo não é alterado. O amendoim forrageiro não deve ser utilizado sob pastejo intenso. Intensidades de pastejo de moderada a muito leniente proporcionam maior massa de forragem pré-pastejo e total acumulada, associada a menores intervalos entre pastejos.

Associative effects between Arachis pintoi and dwarf elephantgrass hays on nutritional value in sheep

The aim of the present study was to evaluate the effect of including different levels of peanut (Arachis pintoi cv. Amarillo) hay (167 and 572 g/kg dry matter (DM) of crude protein and neutral detergent fibre respectively) on the nutritional value of diets based on dwarf elephantgrass (Pennisetum purpureum Shum, cv. Kurumi) hay (98 and 668 g/kg DM of crude protein and neutral detergent fibre respectively). Peanut hay was included in the proportions of 0.0, 0.33, 0.66 and 1.00 of total diet DM. Eight Texel × Suffolk crossbred wethers provided with duodenal cannula were assigned to the treatments in a replicated 4 × 4 Latin-square experiment. The organic matter (OM) intake increased linearly (P < 0.05) and the total apparent OM digestibility decreased linearly (P < 0.001) with an increasing inclusion of legume. The nitrogen (N) intake and N urinary excretion increased linearly (P < 0.05), whereas linear and quadratic responses were significant for digestible OM intake, N retention, and for the efficiency of rumen microbial protein synthesis. Cubic positive responses were significant (P < 0.05) for duodenal flow of total N, non-ammonia-N and rumen microbial-N. The inclusion of A. pintoi in dwarf elephantgrass-based diets improved the nutrient supply to sheep, but no additive effect was observed as a result of increasing the peanut proportion in the mixed diet.

Produção, composição botânica e composição química de missioneira-gigante consorciada com leguminosas perenes

Mixed pastures is a viable alternative to increase forage production and the association of two species (legume and grass) in the same area can improve the nutritional value of animal diet. To evaluate the dry mass forage and chemical composition of giant missionary (GM) pasture (Axonopus catharinensis Valls.) intercropped or not with perennial legume species it was conducted this experiment. The randomized complete block design was used, with three replications in a split plot scheme. In the plots were tested three treatments: MG single crop; MG + forage peanut (FP) (Arachis pintoi cv. Bushel); and MG + Lotus serrano” (LS) (Lotus uliginosus cv. SCS 313 Serrano). The subplots were composed of seven forage cutting times from November 2011 to November 2012. There was interaction between the experimental factors for all variables. The GM intercropping with LS or FP increased the dry matter forage during the spring and summer period. The botanical composition changed during the evaluation period, with reduced participation of LS from 39 to 10%. The participation of FP forage remained at around 8%, but in the winter, this species did not growth. The chemical composition of the forage was influenced by the botanical composition. The higher crude protein content and digestibility was observed in GM + LS. The results indicate that FP and LS show high potential in for intercropping with GM, although the persistence of LS require further assessment.

Herbage intake, methane emissions and animal performance of steers grazing dwarf elephant grass v. dwarf elephant grass and peanut pastures

Management strategies for increasing ruminant legume consumption and mitigating methane emissions from tropical livestock production systems require further study. The aim of this work was to evaluate the herbage intake, animal performance and enteric methane emissions of cattle grazing dwarf elephant grass (DEG) (Pennisetum purpureum cv. BRS Kurumi) alone or DEG with peanut (Arachis pintoi cv. Amarillo). The experimental treatments were the following: DEG pastures receiving nitrogen fertilization (150 kg N/ha as ammonium nitrate) and DEG intercropped with peanut plus an adjacent area of peanut that was accessible to grazing animals for 5 h/day (from 0700 to 1200 h). The animals grazing legume pastures showed greater average daily gain and herbage intake, and shorter morning and total grazing times. Daily methane emissions were greater from the animals grazing legume pastures, whereas methane emissions per unit of herbage intake did not differ between treatments. Allowing animals access to an exclusive area of legumes in a tropical grass-pasture-based system can improve animal performance without increasing methane production per kg of dry matter intake.

Herbage intake and animal performance of cattle grazing dwarf elaphant grass with two access times to a forage peanut area

Relatively short grazing periods in a pure legume pasture can be an alternative for increasing animal performance in medium-quality tropical pastures. Thus, the aim was to evaluate the herbage intake and animal performance of steers grazing dwarf elephant grass (Pennisetum purpureum Schum. cv. BRS Kurumi) with two access times [2 h (07:00 - 9:00) and 6 h (07:00 - 13:00)] to an area of forage peanut (Arachis pintoi cv. Amarillo). Twelve steers (219 ± 28.8 kg LW) were divided into four groups and assessed during three consecutive grazing cycles, from January to March 2013. The crude protein and neutral detergent fiber contents were 158 and 577 g/kg dry matter (DM) for dwarf elephant grass and 209 and 435 g/kg DM for forage peanut, respectively. The pre-grazing height and leaf mass of dwarf elephant grass and forage peanut were 94 cm and 2782 kg DM/ha and 15 cm and 1751 kg DM/ha, respectively. The herbage intake (mean = 2.7 ± 0.06% LW) and average daily weight gain (mean = 1.16 ± 0.31 kg/day) were similar for both treatments. However, animals with 2-h access to the legume paddock grazed for 71% of the time, whereas those with 6-h access grazed for 48% of the time. The performance of the steers that were allowed to graze forage peanut pasture for 2 h is similar to that of those that were allowed to graze the legume pasture for 6 h.

Intake and digestion of wethers fed with dwarf elephant grass hay with or without the inclusion of peanut hay.

The aim of this study was to evaluate the effect of the inclusion of peanut (Arachis pintoi cv. Amarillo) hay in diets based on dwarf elephant grass (DEG, Pennisetum purpureum Schum cv. Kurumi) hay of different regrowth ages on forage intake and digestibility in wether lambs. The experimental treatments consisted of DEG hay with an interval of regrowth of 30 or 45 days offered as the only feed or in mixture with peanut hay (300 g/kg of total dry matter (DM)), which were tested in eight Texel × Suffolk crossbred wethers in a replicated 4 × 4 Latin square experiment. Both organic matter (OM) and digestible OM intakes were higher (P < 0.05) in animals receiving the legume forage. Total apparent OM digestibility was higher (P < 0.05) at an increased grass regrowth age. Ruminal OM digestibility increased (P < 0.05) with legume inclusion and at a higher grass regrowth age. The nitrogen (N) intake was higher (P < 0.05) in legume treatments and lower (P < 0.05) as the grass regrowth age increased, but retention of N was not affected by treatments. Duodenal flow of both, non-ammonia N and microbial N, were not affected by legume inclusion and were lower (P < 0.05) as grass regrowth age increased. The efficiency of rumen microbial protein synthesis (ERMPS) was negatively affected (P < 0.05) by legume inclusion and was lower (P < 0.05) as the grass regrowth age increased. Supplementation of dwarf elephant grass hay cut at the vegetative stage with peanut legume hay improves nutritional supply to wethers due to an increase in the forage intake.

Herbage intake, methane emissions and animal performance of steers grazing dwarf elephant grass with or without access to Arachis pintoi pastures

The inclusion of legumes in diets based on grass has nutritional benefits due to ingestive and digestive interactions (Niderkorn and Baumont 2009). Moreover, it is speculated that tropical legumes can contribute to reducing the emission of greenhouse gases (GHG) compared with diets exclusively composed of grasses (Archimede et al. 2011). However, under grazing conditions, these advantages are not always possible to obtain. This occurs when the spatial distribution of sward grasses limits access to legumes by grazing animals (Solomon et al. 2011). This can be the case, for example, when legumes are overlapped by the leaves of a tufted tall grass like dwarf elephant grass (Crestani et al. 2013). Considering that management strategies for increasing legume percentage in the diet of grazing animals should be investigated and data on enteric methane emitted by ruminants eating tropical forages are scarce, the aim of this work was to evaluate the effects on herbage intake, animal performance and enteric methane emissions of providing access to an exclusive area of forage peanut (Arachis pintoi cv. Amarillo) for cattle grazing dwarf elephant grass (Pennisetum purpureum cv. BRS Kurumi).

In situ degradability and selected ruminal constituents of sheep fed with peanut forage hay

Because legumes are a very important feed source for ruminants, the aim of this study was to evaluate the ideal inclusion level of hay Arachis pintoi cv. Belmonte in sheep diets by measuring the dry matter intake (DMI), concentration of volatile fatty acids, ammonia–nitrogen concentration, ruminal pH and the in situ degradability of dry matter (DM) and crude protein (CP). In the experiment with four sheep, a 4 × 4 Latin Square design was used with four periods and four treatments (0%, 30%, 60% and 100% Arachis replacing grass hay). Significant interactions were observed between treatments and sampling times for ammonia–nitrogen and acetate, propionate and butyrate concentration and the acetate:propionate ratio. The ruminal pH and total volatile fatty acids concentration were not affected by interaction between treatments and sampling time. The degradation of DM and CP was similar, rising with the increasing content of Arachis, showing a linear effect. The treatment containing 60% of Arachis showed best results, with good levels of daily weight gain and higher ruminal concentrations of volatile fatty acids. The legume showed high levels of CP, high digestibility and appropriate levels of fibre, with excellent standards of degradation and ruminal characteristics. The use of the legume Arachis for ruminants is a promising option of nutrient supply to meet production demands of these animals.

Steers performance in dwarf elephant grass pastures alone or mixed with Arachis pintoi

The inclusion of legumes in pasture reduces the need for mineral nitrogen applications and the pollution of groundwater; however, the agronomic and animal husbandry advantages with tropical legumes are still little known. The objective of this study was to quantify the effect of the use of forage peanut (Arachis pintoi cv. Amarillo) in dwarf elephant grass pastures (Pennisetum purpureum cv. BRS Kurumi) on forage intake and animal performance. The experimental treatments were dwarf elephant grass fertilized with 200 kg N/ha, and dwarf elephant grass mixed with forage peanut without mineral fertilizers. The animals used for the experiment were 12 Charolais steers (body weight (BW) = 288 ± 5.2 kg) divided into four lots (two per treatment). Pastures were managed under intermittent stocking with an herbage allowance of 5.4 kg dry matter of green leaves/100 kg BW. Dry matter intake (mean = 2.44 % BW), the average daily gain (mean = 0.76 kg), and the stocking rate (mean = 3.8 AU/ha) were similar between the studied pastures, but decreased drastically in last grazing cycle with the same herbage allowance. The presence of peanut in dwarf elephant grass pastures was enough to sustain the stocking rate, but did not allow increasing forage intake and animal performance.

Nitrogen fertilization on the establishment of Arachis pintoi cv. Belmonte

The objective was to evaluate the effect of nitrogen fertilization on the establishment of forage peanut (Arachis pintoi cv. Belmonte) propagated vegetatively. The experiment was conducted in a greenhouse in a completely randomized design with treatments arranged in a 2 × 4 factorial design - two ages (70 and 85 days after planting) and four nitrogen doses (0, 40, 80 and 120 kg/ha) - with four replications. Morphogenetic and structural characteristics and production were evaluated. The nitrogen accelerated the establishment of the forage peanut with an increase in dry weight of green leaves and stolons. The greatest length of stolons (48.0 cm) was obtained with a dose equivalent to 86 kg N/ha and higher density of stolons (20 stolons/vase) between 78 and 82 kg N/ha. Nitrogen fertilization also reduced the phyllochron from 6.7 to 4.6 days/leaf. These data were more intense at 85 days, suggesting greater photosynthetic contribution during this period related to the large number of leaves after 70 days. Therefore, nitrogen can be an important tool to accelerate the establishment of pure stands of forage peanut.

Dynamics of sward condition and botanical composition in mixed pastures of marandugrass, forage peanut and tropical kudzu

This study was carried out to evaluate the dynamics of sward condition and botanical composition of a mixed pasture of marandugrass (Brachiaria brizantha cv. Marandu), forage peanut (Arachis pintoi cv. Mandobi) and tropical kudzu (Pueraria phaseoloides), rotationally stocked at four daily forage allowance levels (6.6, 10.3, 14.3 and 17.9% of live weight). Sward condition was characterized in each stocking cycle by measuring pre- and post-grazing sward height, forage mass and percentage of bare ground. Botanical composition (grass, forage peanut, tropical kudzu and weeds) was evaluated before each stocking period. Swards under smaller forage allowances presented lower height, forage mass and ground cover. This condition favored the growth of forage peanut, which constituted 21.1, 15.2, 8.4 and 3.8% of forage mass in the last quarter of the experimental period, from the lowest to the highest forage allowance, respectively. Tropical kudzu was sensitive to all forage allowance levels and its percentage in the botanical composition was strongly reduced along the experimental period, especially during the dry season (July to September). Forage peanut cv. Mandobi and marandugrass form a more balanced mixture when pre-grazing sward height is maintained shorter than 45 cm. Tropical kudzu is intolerant to intensive grazing management systems when associated to marandugrass.