Which Socio-economic Conditions Drive the Selection of Agroforestry at the Forest Frontier?

Models are essential to assess the socio-economic credentials of new agroforestry systems. In this study, we showcase robust optimisation as a tool to evaluate agroforestry's potential to meet farmers' multiple goals. Our modelling approach has three parts. First, we use a discrete land-use model to evaluate two agroforestry systems (alley cropping and silvopasture) and conventional land uses against five socio-economic objectives, focusing on the forest frontier in eastern Panama. Next, we couple the land-use model with robust optimisation, to determine the mix of land uses (farm portfolio) that minimises trade-offs between the five objectives. Here we consider uncertainty to simulate the land-use decisions of a risk-averse farmer. Finally, we assess how the type and amount of agroforestry included in the optimal land-use portfolio changes under different environmental, socio-economic and political scenarios, to explore the conditions that may make agroforestry more attractive for farmers. We identify silvopasture as a promising land use for meeting farmers' goals, especially for farms with less productive soils. The additional labour demand compared to conventional pasture, however, may prove an important barrier to adoption for farms facing acute labour shortages. The selection of agroforestry responded strongly to changes in investment costs and timber prices, suggesting that cost-sharing arrangements and tax incentives could be effective strategies to enhance adoption. We found alley cropping to be less compatible with farmers' risk aversion, but this agroforestry system may still be a desirable complement to the land-use portfolio, especially for farmers who are more profit-oriented and tolerant of risk.

A goal programming approach to evaluate agroforestry systems in Eastern Panama.

Agroforestry is hypothesised to increase ecological and economic functions of farms. Yet it is unclear if and how much agroforestry should be embedded in diversified farming systems to satisfy farmers' needs while potentially enhancing environmental services. To address this research gap we use a mathematical programming model to investigate the role of different agroforestry systems in hypothetical farm portfolios that reduce trade-offs between farmers' goals. Our approach is innovative because it simultaneously considers multiple objectives and the effect of land-use diversification within a farm, is based on knowledge and perceptions of local farmers, and accounts for heterogeneity in farmer judgement. We test the model in a forest frontier region in Eastern Panama, using data from farmer interviews. Farmers evaluated conventional land uses and two agroforestry systems (silvopasture and alley cropping) against 10 pre-defined socio-economic and ecological objectives. First we determined the optimal farm land-use composition that reduces trade-offs between the 10 objectives. The model selects the mix of land uses that secures the best worst-case performance across all objectives, when considering uncertainty in the ability of each land use to achieve each objective (which we quantify by the variability in farmer opinion). Agroforestry dominates the optimised farm portfolio, which comprises 60% silvopasture, 39% forest and 1% plantation. This land-use portfolio, however, deviates strongly from the current land use of farmers, which is 59% pasture, 26% crops, 14% forest and 1% plantation. In a second step we explore the implicit objectives driving farmers' current land-use decisions. We find that immediate-term needs related to food security and liquidity best explain farmers' current land-use portfolio; optimising for these objectives produces a land-use portfolio comprising 60% pasture and 40% crops, which is similar to the current land use. This suggests that increasing agroforestry adoption in the study area will require systems that provide early and frequent returns and allow for ongoing crop production, to better satisfy farmers' cash flow and household consumption needs.

Modeling shade tree use by beef cattle as a function of black globe temperature and time of day.

Increasing temperatures associated with global climate change threaten to disrupt agricultural systems such as beef production, yet relatively little is known about the use of natural tree shade to mitigate the negative effects of heat stress on beef cattle. In this study, we evaluated how temperature and time of day influenced the utilization of tree shade in relation to coloration, orientation, and behavior of beef cattle in a pasture system. Temperatures in shade and direct sunlight were measured using black globe temperature (BGT) data loggers. Time-lapse images from game cameras were used to obtain counts of shade usage, coloration, orientation, and behavior of cattle throughout the daytime hours. In general, we found that shade utilization and most of the predominating orientations and behaviors differed significantly (P < 0.05) by both time of day (Hour) and BGT in direct sunlight (BGTsun), while interactions between these two effects (Hour × BGTsun) were often nonsignificant. The mean percentage of the herd using shade was highest in mid-morning (87-96%) and early afternoon (97%), but also increased with BGTsun regardless of the time of day; these trends were similar for both dark- and light-colored cattle. Lying down was the dominant behavior exhibited in the shade, while foraging was the most prevalent behavior in the sun. When herd shade usage was lowest in mid- to late-afternoon (<1%) we also observed an increase in the use of heat-mitigating orientations in the sun (37-47%). We discuss some practical implications of these results, including the potential use of temperature thresholds to interpret cattle behaviors and shade usage.

Silvopastoral systems benefit invertebrate biodiversity on tropical livestock farms in Caquetá, Colombia.

In the Colombian Amazon, there has been long-term and sustained loss of primary forest threatening biodiversity and climate change mitigation. Silvopastoral practices that integrate trees into livestock production could help address both local economic and wider environmental challenges.We aimed to assess the effects of silvopastoral practices on invertebrate communities on smallholder farms in Caquetá, Colombia. Using sweep nets and malaise trapping, invertebrate communities were compared between traditional pasture, silvopasture and forest edge habitats.Invertebrate communities collected using sweep nets were contrasting among habitat types, communities were significantly different between traditional pasture and forest edge habitats and diversity and evenness were greatest in forest edges compared to traditional pastures. It appears that silvopasture areas, by supporting similar invertebrate assemblages to both traditional pasture and forest edges, may be acting as an intermediate habitat.When individual invertebrate orders were compared, Lepidoptera and Coleoptera were found in greater abundance in the forest edge habitats, while Hemiptera were more abundant in traditional pasture. Hemipterans are often pests of forage plants in pasture systems and these differences in abundance may have implications for ecosystem services and disservices.Silvopastoral approaches cannot replace the unique biodiversity supported by native forests but could deliver benefits for invertebrate conservation and ecosystem services if integrated into landscapes.

Resumen: En la Amazonía colombiana ha habido una pérdida sostenida y a largo plazo de bosque primario que amenaza la biodiversidad y la mitigación del cambio climático. Las prácticas silvopastoriles que integran los árboles en la producción ganadera podrían ayudar a abordar tanto los desafíos económicos locales como los ambientales.Nuestro objetivo fue evaluar los efectos de las prácticas silvopastoriles en comunidades de invertebrados en pequeñas fincas en Caquetá, Colombia. Las comunidades de invertebrados se compararon entre las pasturas nativas, el sistema silvopastoril y los hábitats del borde del bosque mediante el uso redes entomológicas de barrido y trampas Malaise.Las comunidades de invertebrados recolectadas usando redes entomológicas de barrido contrastaban entre los tipos de hábitat. Las comunidades eran significativamente diferentes entre las pasturas nativas y el borde de bosque. Pareciera que las áreas de silvopastoreo, al soportar conjuntos de invertebrados similares tanto a las pasturas nativas como a los bordes del bosque, pueden estar actuando como un hábitat intermedio.Cuando se compararon los órdenes individuales de invertebrados, los lepidópteros y los coleópteros se encontraron en mayor abundancia en los hábitats del borde del bosque, mientras que los hemípteros eran más abundantes en las pasturas nativas. Los hemípteros son a menudo plagas de plantas forrajeras en sistemas de pastoreo y estas diferencias en abundancia pueden tener implicaciones y perjuicios para los servicios ecosistémicos.Los sistemas silvopastoriles no pueden reemplazar la biodiversidad única apoyada por los bosques nativos, pero podrían ofrecer beneficios para la conservación de invertebrados y los servicios ecosistémicos si se integran en los paisajes.

Maximizing tree carbon in croplands and grazing lands while sustaining yields.

BACKGROUND: Integrating trees into agricultural landscapes can provide climate mitigation and improves soil fertility, biodiversity habitat, water quality, water flow, and human health, but these benefits must be achieved without reducing agriculture yields. Prior estimates of carbon dioxide (CO2) removal potential from increasing tree cover in agriculture assumed a moderate level of woody biomass can be integrated without reducing agricultural production. Instead, we used a Delphi expert elicitation to estimate maximum tree covers for 53 regional cropping and grazing system categories while safeguarding agricultural yields. Comparing these values to baselines and applying spatially explicit tree carbon accumulation rates, we develop global maps of the additional CO2 removal potential of Tree Cover in Agriculture. We present here the first global spatially explicit datasets calibrated to regional grazing and croplands, estimating opportunities to increase tree cover without reducing yields, therefore avoiding a major cost barrier to restoration: the opportunity cost of CO2 removal at the expense of agriculture yields. RESULTS: The global estimated maximum technical CO2 removal potential is split between croplands (1.86 PgCO2 yr- 1) and grazing lands (1.45 PgCO2 yr- 1), with large variances. Tropical/subtropical biomes account for 54% of cropland (2.82 MgCO2 ha- 1 yr- 1, SD = 0.45) and 73% of grazing land potential (1.54 MgCO2 ha- 1 yr- 1, SD = 0.47). Potentials seem to be driven by two characteristics: the opportunity for increase in tree cover and bioclimatic factors affecting CO2 removal rates. CONCLUSIONS: We find that increasing tree cover in 2.6 billion hectares of agricultural landscapes may remove up to 3.3 billion tons of CO2 per year - more than the global annual emissions from cars. These Natural Climate Solutions could achieve the Bonn Challenge and add 793 million trees to agricultural landscapes. This is significant for global climate mitigation efforts because it represents a large, relatively inexpensive, additional CO2 removal opportunity that works within agricultural landscapes and has low economic and social barriers to rapid global scaling. There is an urgent need for policy and incentive systems to encourage the adoption of these practices.

How does Life Cycle Assessment capture the environmental impacts of agroforestry? A systematic review.

In this paper, a systematic review approach was used to evaluate how environmental Life Cycle Assessment (LCA) has been applied in agroforestry in the context of food systems. This review was used as the basis for discussing methodological issues in the LCA framework for agroforestry systems (AFS) and relevant environmental outcomes in the agroforestry literature. A total of 32 LCAs in 17 countries identified in four databases and spanning a decade form the basis for this paper. Studies were selected based on pre-defined inclusion criteria and followed established guidelines and a review protocol. Qualitative data were extracted and categorized into multiple themes. Results were quantitatively synthesized for the four phases of the LCA for each individual agroforestry practice (i.e., based on its structural composition). Results showed that around half of the selected studies are located in tropical climates, the rest being in temperate climates, predominantly in Southern Europe. Studies primarily used a mass functional unit and rarely included post-farm gate system boundaries. Almost half of the studies account for multifunctionality, and most allocation methods were based on physical properties. Climate change had the greatest coverage from all impact categories with some variations within milk, meat, and crop production systems. Methodological issues were related to limited system boundaries, few impact categories, and differing functional units and multifunctionality approaches. The identified effects of AFS on biodiversity, climate change mitigation, water, soil, pollination, and pest and disease were only partially documented or not analyzed in the LCA studies or the LCA framework. Gaps in knowledge and limitations of the present review were discussed. Further methodological improvements remain necessary to determine the net environmental effects of food products resulting from individual AFS, especially within the area of multifunctionality, carbon sequestration, and biodiversity.

Supplement Type Impact on the Performance and Nutrient Dynamics of Nursing Does and Kids Raised in Woodlands.

The influence of different supplement types on the performance and nutrient dynamics of goats stocked in woodlands is not known. The objective of this study was to evaluate the effect of supplement type on the performance and the concentration of fecal nutrients of nursing does and the performance of kids raised in woodlands. One group of goats (SG, 9 does; 18 kids) was allowed supplemental grazing in adjacent silvopasture plots for 3-4 h daily and another group (SF, 8 does; 15 kids) was supplemented with corn (0.5% of metabolic weight) and ad libitum hay. Vegetation samples were collected and analyzed for productivity and quality (crude protein, CP; acid detergent fiber, ADF; neutral detergent fiber, NDF). The quality of the hay (N, ADF, NDF) and fecal samples (N, P, Ca) was analyzed. The animals' live weight, FAMACHA score, and body condition score were collected. The browsing height for does consuming woodland vegetation was measured. Data were analyzed using the GLM procedure, Mixed procedure, and MEANS procedure in SAS 9.4. SG does showed better FAMACHA scores vs. SF does (p < 0.05). Fecal N and ADF were greater (p < 0.0001) in SG does vs. SF does. The findings showed a better performance and greater concentration of fecal nutrients in SG does vs. SF does, suggesting grazing quality pastures is a better option than using feedstuffs to supplement nursing does in woodland.

Reply to: "Research on agroforestry systems and biodiversity conservation: what can we conclude so far and what should we improve?" by Boinot et al. 2022.

In our article 'European agroforestry has no unequivocal effect on biodiversity: a time-cumulative meta-analysis' (BMC Ecology and Evolution, 2021) we synthesize the effect of agroforestry on biodiversity. Boinot et al. (BMC Ecology and Evolution, 2022) criticise our approach arguing that our definitions of agroforestry and biodiversity are too narrow; that we use inappropriate control sites for primary studies lacking distance to the treatment sites; that there are too few studies for a meta-analysis in silvoarable systems; and that local practice should be emphasized. We agree on the importance of local practices and that more studies would improve the robustness of our meta-analytical results. However, our conclusions are robust to removing studies criticised for inappropriate controls. We also recognize the problem of different definitions of agroforestry and using species richness as sole proxy for biodiversity. We appreciate being given the opportunity to clarify our results and to trigger future discussions about definitions and the interpretation of results from meta-analysis.

European agroforestry has no unequivocal effect on biodiversity: a time-cumulative meta-analysis.

BACKGROUND: Agroforestry is a production system combining trees with crops or livestock. It has the potential to increase biodiversity in relation to single-use systems, such as pastures or cropland, by providing a higher habitat heterogeneity. In a literature review and subsequent meta-analysis, we investigated the relationship between biodiversity and agroforestry and critically appraised the underlying evidence of the results. RESULTS: Overall, there was no benefit of agroforestry to biodiversity. A time-cumulative meta-analysis demonstrated the robustness of this result between 1991 and 2019. In a more nuanced view silvopastoral systems were not more diverse in relation to forests, pastures or abandoned silvopastures. However, silvoarable systems increased biodiversity compared to cropland by 60%. A subgroup analysis showed that bird and arthropod diversity increased in agroforestry systems, while bats, plants and fungi did not. CONCLUSION: Agroforestry increases biodiversity only in silvoarable systems in relation to cropland. But even this result is of small magnitude, and single-study effect sizes were heterogeneous with sometimes opposing conclusions. The heterogeneity suggests the importance of other, usually unmeasured variables, such as landscape parameters or land-use history, influencing biodiversity in agroforestry systems.

Browse from Three Tree Legumes Increases Forage Production for Cattle in a Silvopastoral System in the Southwest Amazon.

Assessing the palatability of forage from locally adapted trees could improve the sustainability of livestock production systems. However, grasses continue to dominate livestock feed across the Amazon. We established a silvopastoral cattle farming system in Peru, comparing three different forage tree species with grass monocultures using a randomised block design. Trees were arranged in alleys of 0.5 × 7.5 m, planted alongside grass, and were directly browsed by cattle. Browse removal was estimated by three methods: destructive sampling, canopy measurements and leaf counts. We found that all three tree species were palatable to cattle. Plots containing trees and grass produced more available forage (mean > 2.2 Mg ha-1) for cattle than the grass monocultures (mean = 1.5 Mg ha-1). Destructive sampling below 1.6 m demonstrated that cattle consumed 99% of the available Erythrina berteroana forage, 75% of the available Inga edulis forage and 80% of the available Leucaena leucocephala forage in 8 days. This research demonstrates methodologies to estimate the intake of locally adapted browse species by cattle and highlights the potential benefits of silvopastoral systems in the Amazon. Planting trees could also benefit animal health and provide ecosystem services such as soil regeneration, enhanced nutrient cycling and carbon capture.

Trees on farms to support natural capital: An evidence-based review for grazed dairy systems.

Intensification of the dairy industry globally, combined with a changing climate, has placed increased pressure on natural capital assets (and the flow of ecosystem services) on farms. Agroforestry is widely promoted as an intervention to address these issues. While some benefits of integrating trees on farms, such as carbon sequestration and biodiversity, are reasonably well known, less is known about other potential benefits, such as on-farm production. Understanding and quantifying these benefits would inform farm planning and decision-making. We used a systematic review approach to analyse the evidence base for biophysical ecosystem services from woody systems (including shelterbelts, riparian plantings, plantations, pasture trees, silvopasture and remnant native vegetation) provided to grazed dairy enterprises. We identified 83 publications containing 123 records that fit our review criteria of reporting on biophysical ecosystem services from woody systems on dairy farms relative to a grazed pasture comparison. For each relationship between a woody system and ecosystem service, we assessed the level of support, strength and predominant direction of evidence, and summarised the causal relationships (woody system ≫ mechanism ≫ outcome). Shelterbelts and riparian plantings were the most commonly reported woody systems. Linkages between woody systems and ecosystem services were largely positive, with the types of services provided and their importance differing among systems. Mean evaluation scores for the strength of the evidence were moderate to strong. However, the number of records for each relationship was often low. Consequently, only eight of the 30 causal pathways identified had high confidence; a further 14 had medium confidence indicating that these have good potential to deliver benefits but warrant further work. Although the evidence here was largely qualitative, our results provide strong support for the internal benefits that natural capital assets, such as on-farm woody systems, can provide to the productivity and resilience of grazed dairy enterprises.

Ecological intensification and diversification approaches to maintain biodiversity, ecosystem services and food production in a changing world.

How do we redesign agricultural landscapes to maintain their productivity and profitability, while promoting rather than eradicating biodiversity, and regenerating rather than undermining the ecological processes that sustain food production and are vital for a liveable planet? Ecological intensification harnesses ecological processes to increase food production per area through management processes that often diversify croplands to support beneficial organisms supplying these services. By adding more diverse vegetation back into landscapes, the agricultural matrix can also become both more habitable and more permeable to biodiversity, aiding in conserving biodiversity over time. By reducing the need for costly inputs while maintaining productivity, ecological intensification methods can maintain or even enhance profitability. As shown with several examples, ecological intensification and diversification can assist in creating multifunctional landscapes that are more environmentally and economically sustainable. While single methods of ecological intensification can be incorporated into large-scale industrial farms and reduce negative impacts, complete redesign of such systems using multiple methods of ecological intensification and diversification can create truly regenerative systems with strong potential to promote food production and biodiversity. However, the broad adoption of these methods will require transformative socio-economic changes because many structural barriers continue to maintain the current agrichemical model of agriculture.

Introducing trees to agricultural lands increases greenhouse gas emission during spring thaw in Canadian agroforestry systems.

The role of agroforestry systems in mitigating greenhouse gas (GHG) emission from agricultural soils during spring thaw (early April to mid-May) has been poorly studied. Soil CO2, CH4 and N2O fluxes were measured from treed areas and adjacent herblands (areas without trees) during spring thaw in 2014 and 2015 at 36 agroforestry sites (12 hedgerow, 12 shelterbelt and 12 silvopasture) in central Alberta, Canada. Fluxes of those GHGs varied with agroforestry systems and land-cover types. We found greater CO2 emission (P < 0.001) and CH4 uptake (P < 0.05), but lower N2O emission (P < 0.01) in the silvopasture than in the hedgerow and shelterbelt systems, with no difference between the last two systems. Treed areas in general had greater CO2 emissions (P < 0.001) and CH4 uptake (P < 0.01), and lower N2O emissions (P < 0.001) than the herblands. Soil temperature, moisture content, organic C content and soil available N concentration affected GHG fluxes. The global warming potential (GWP) was greater (P < 0.05) in the silvopasture than in the hedgerow or shelterbelt systems over the two spring thaw seasons examined, and greater (P < 0.05) in the treed areas than in the herblands during the cool spring in 2015. However, the GWP per unit soil organic C was lower in the treed areas (0.004-0.101%) than in the herblands (0.005-0.225%). As compared to previously reported mean growing season GHG emission (15.4 g CO2-eq m-2 day-1), the GWP of these land uses during spring thaw was small (<5% of the annual GWP) due to the short spring period (6 weeks) and the small GHG emission (2.5 g CO2-eq m-2 day-1). Although GHG emissions during spring thaw were small compared to those in the growing season, they should not be ignored.

Grazing and abandonment determine different tree dynamics in wood-pastures.

Wood-pastures are threatened biotopes in which trees and livestock grazing maintain high conservation values. However, browsing may threaten tree regeneration, whereas abandonment leads to tree encroachment. We studied the regeneration of trees in a grazed and abandoned boreal wood-pastures. In grazed sites, the density of young spruces (Picea abies) was high, while the density of young birches (Betula spp.) was very low. Sprucification can be prevented only by removing spruces. The number of young birches and pines (Pinus sylvestris) was correlated with the number of junipers (Juniperus communis), probably because thorny junipers protect palatable seedlings from browsing. In abandoned sites, deciduous trees and spruces regenerated abundantly. In the long term, both grazing and abandonment lead to changes in tree species compositions and low diversity wood-pastures. Landscape scale planning and disturbance dynamics are needed for the creation of new wood-pastures and the maintenance of all pasture types within the landscape.

Forest and grassland cover types reduce net greenhouse gas emissions from agricultural soils.

Western Canada's prairie region is extensively cultivated for agricultural production, which is a large source of greenhouse gas emissions. Agroforestry systems are common land uses across Canada, which integrate trees into the agricultural landscape and could play a substantial role in sequestering carbon and mitigating increases in atmospheric GHG concentrations. We measured soil CO2, CH4 and N2O fluxes and the global warming potential of microbe-mediated net greenhouse gas emissions (GWPm) in forest and herbland (areas without trees) soils of three agroforestry systems (hedgerow, shelterbelt and silvopasture) over two growing seasons (May through September in 2013 and 2014). We measured greenhouse gas fluxes and environmental conditions at 36 agroforestry sites (12 sites for each system) located along a south-north oriented soil/climate gradient of increasing moisture availability in central Alberta, Canada. The temperature sensitivity of soil CO2 emissions was greater in herbland (4.4) than in forest (3.1), but was not different among agroforestry systems. Over the two seasons, forest soils had 3.4% greater CO2 emission, 36% higher CH4 uptake, and 66% lower N2O emission than adjacent herbland soils. Combining the CO2 equivalents of soil CH4 and N2O fluxes with the CO2 emitted via heterotrophic (microbial) respiration, forest soils had a smaller GWPm than herbland soils (68 and 89kgCO2ha(-1), respectively). While emissions of total CO2 were silvopasture>hedgerow>shelterbelt, soils under silvopasture had 5% lower heterotrophic respiration, 15% greater CH4 uptake, and 44% lower N2O emission as compared with the other two agroforestry systems. Overall, the GWPm of greenhouse gas emissions was greater in hedgerow (88) and shelterbelt (85) than in the silvopasture system (76kgCO2ha(-1)). High GWPm in the hedgerow and shelterbelt systems reflects the greater contribution from the monoculture annual crops within these systems. Opportunities exist for reducing soil greenhouse gas emissions and mitigating climate change by promoting the establishment of perennial vegetation in the agricultural landscape.

Desempeño de bancos forrajeros de Cratylia argentea (Desv.) Kuntze, en suelos degradados en el departamento de Casanare / Performance of the Cratylia argentea (Desv.) Kuntze Forage Banks in Degraded Soils in the Casanare Province / Desempenho de bancos de forragem de Cratylia argentea (Desv.) Kuntze, em solos degradados no departamento de Casanare

Resumen Las épocas de sequía o lluvias extremas afectan la eficiencia en los sistemas ganaderos, los cuales basan la producción de forrajes en el monocultivo de gramíneas, estas son más vulnerables a las condiciones climáticas extremas, lo que hace necesario buscar alternativas de plantas más resistentes a estas condiciones. Se determinó el desempeño de Cratylia argentea en bancos forrajeros, establecidos en suelos degradados con alto uso de agroquímicos, bajo condiciones de bosque húmedo tropical. El estudio se realizó durante un año y se estableció en la finca Matapantano, ubicada en Yopal, Casanare (Colombia), se determinó el efecto sobre las propiedades físico-químicas y macrofauna del suelo, producción de forraje verde y materia seca, relación hoja-tallo, calidad nutricional de la planta completa y fracciones (hoja-tallo). Se utilizó un diseño al azar y el software Infostat® para estadística descriptiva y análisis de varianza no paramétrica. Se presentaron incrementos en los contenidos de minerales, materia orgánica, carbono orgánico y macrofauna del suelo, se encontraron diferencias en producción de materia seca de las fracciones de la planta (p < 0.0001), en la producción de materia seca entre cortes (p < 0.0001) y en la relación hoja-tallo (p < 0.0001), el forraje presentó buena calidad nutricional, siendo las hojas la fracción de mejor calidad, C. argentea resistió los cambios drásticos en las condiciones climáticas. Se concluye que esta especie, presenta potencial para la recuperación de suelos degradados con intenso uso de agroquímicos, puesto que produce forraje de buena calidad para la suplementación animal en sistemas ganaderos, aun en épocas de sequía.

Abstract Extreme drought or rainy seasons affect the efficiency in the stockbreeding systems whose forage production is based on the grass monoculture. These species are more vulnerable to the extreme climate conditions, which requires looking for alternative plants with higher resistance to these conditions. This work studied the Cratylia argentea performance in forage banks used in degraded soils with high amounts of agrochemicals in areas of tropical rainforest. The study took one year and was conducted in the estate Matapantano, located in Yopal, Casanare (Colombia). The effect on the physical-chemical properties and macrofauna in this soil, the green forage and dry mass production, the leaf-stalk relationship, the nutritional quality of both fractions (leaf-stalk) and the whole plant were studied. A random design and the software Infostat® were used for the descriptive statistics and the non-parametric variance analysis. The soil showed increases in the contents of minerals, organic mass, organic carbon and macrofauna. Differences were observed in the dry mass production from the plant fractions (p < 0.0001), in the dry mass production between cuts (p < 0.0001) and in the leaf-stalk relationship (p < 0.0001). The forage showed a good nutritional quality and the leaves were the fraction with best quality. C. argentea resisted the extreme changes in the climate conditions. It is concluded that the studied species has a good potential for the recovery of degraded soils with intense use of agrochemicals as it produced good quality forage to feed animals in stockbreeding systems, even in the drought season.

Resumo As secas ou chuvas extremas afetam a eficiência dos sistemas pecuários, os quais baseiam a produção de forragem na monocultura de gramíneas, são mais vulneráveis às condições climáticas extremas, o que faz necessário procurar alternativas de plantas mais resistentes a essas condições. O desempenho de Cratylia argentea foi determinado em bancos de forragem estabelecidos em solos degradados com alto uso de agroquímicos, em condições de floresta húmida tropical. O estudo foi realizado por um ano na finca Matapantano, localizada em Yopal, Casanare (Colômbia). Determinou-se o efeito nas propriedades físico-químicas e macrofauna do solo, produção de forragem verde e matéria seca, relação folha/ caule, qualidade nutricional da planta completa e frações (folha/caule). Utilizou-se delineação aleatória e software Infostat® para estatística descritiva e análise de variância não paramétrica. Houve acréscimos nos teores de minerais, matéria orgânica, carbono orgânico e macrofauna do solo, encontraram-se diferenças na produção de matéria seca das frações da planta (p < 0.0001), na produção de matéria seca entre os cortes (p < 0.0001) e na relação folha-caule (p < 0.0001), a forragem apresentou boa qualidade nutricional, sendo as folhas a fracção de melhor qualidade, C. argentea resistiu às mudanças drásticas nas condições climáticas. Conclui-se que esta espécie apresenta potencial para a recuperação de solos degradados com intenso uso de agroquímicos, uma vez que produz forragem de boa qualidade para a suplementação animal em sistemas pecuários mesmo em épocas de seca.

Criação de bovinos em sistema silvipastoril com eucalipto: um risco para intoxicação por Ramaria flavo-brunnescens / Cattle in silvipasture system with eucalyptus: a risk for Ramaria flavo-brunnescens poisoning

O objetivo deste trabalho foi descrever e discutir os aspectos epidemiológicos de surtos de intoxicação espontânea por Ramaria flavo-brunnescens em bovinos criados em sistema silvippastoril na região sul do Rio Grande do Sul. Foram diagnosticados três surtos da enfermidade entre 2011 e 2013. Em dois surtos a morbidade foi de 35 por cento e 37,4 por cento e a mortalidade foi de 36,12 por cento e 16 por cento, respectivamente. A letalidade nos surtos foi de 45,71 por cento e 96,55 por cento. O diagnóstico foi confirmado pela epidemiologia e presença do cogumelo nas áreas onde os bovinos estavam, além dos sinais clínicos e lesões macroscópicas e histológicas características. Os dados climáticos de temperatura, umidade e precipitação pluviométrica foram analisados estatisticamente; não se observou diferenças de 2007 a 2013. Não foi possível confirmar se a presença de R. flavo-brunnescens nos bosques de eucaliptos está associada a outonos chuvosos e quentes após verões secos. É provável que outros fatores estejam associados à presença do cogumelo nos bosques e à sua toxicidade. A influência do solo e a finalidade da mata plantada podem também, determinar a presença ou não do cogumelo na área. É provável que a espécie de eucalipto seja também um fator determinante para a ocorrência do cogumelo, já que em muitas matas deste gênero o vegetal R. flavo-brunnecens não ocorre. O reconhecimento do cogumelo por trabalhadores e produtores rurais e a época em que o mesmo se desenvolve nos bosques de eucalipto é fundamental para minimizar as perdas econômicas causadas pela intoxicação.

The aim of this study was to describe and discuss the epidemiological aspects of spontaneous outbreaks of poisoning by Ramaria flavo-brunnescens in cattle maintained in silvipasture system in Southern Brazil. Three outbreaks of the disease between 2011 and 2013 were diagnosed. In two outbreaks morbidity was 35 percent and 37.4 percent, and the mortality rate was 36.12 percent and 16 percent, respectively. The fatality rate in these outbreaks was 45.71 percent and 96.55 percent. The diagnosis was confirmed by the epidemiology and the presence of the mushroom in the areas where the cattle grazed, in addition to the clinical signs, gross and histological lesions. The climatic data of temperature, humidity and rainfall were statistically analyzed and no significant differences were observed between the years 2007-2013. It was not possible to confirm that the presence of R. flavo-brunnescens in eucalyptus groves is associated with rainy autumns and warm dry summers. It is likely that other factors are associated with the presence of the mushroom in the woods and its toxicity. The soil and type of forest planted may also determine the presence of the mushroom in the area. It is possible that the species of eucalyptus is also a determining factor for the occurrence of the mushroom, since in many eucalyptus forests R. flavo-brunnescens does not occur. The recognition of the mushroom by workers and farmers and the time for its development in the eucalyptus woods is essential to minimize economic losses caused by the poisoning.

Producción de metano in vitro de dos gramíneas tropicales solas y mezcladas con Leucaena leucocephala o Gliricidia sepium / In vitro methane production from two tropical grasses alone or in combination with Leucaena leucocephala or Gliricidia sepium / Produção in vitro de metano a partir duas gramíneas tropicais avaliadas individualmente e associadas com Leucaena leucocephala ou Gliciridia sepium

La percepción del cambio climático como uno de los grandes problemas ambientales del siglo XXI viene creciendo en las últimas décadas. La emisión de metano por fermentación ruminal es una pérdida de energía potencialmente utilizable. El objetivo fue estimar las emisiones de metano de forrajes usados en dietas para alimentar bovinos. Las dietas evaluadas provenían de un sistema silvopastoril intensivo (SSPi) con leucaena (Leucaena leucocephala; Leu) y pasto guinea (Megathyrsus maximus; Gui) y de confinamiento con matarratón (Gliricidia sepium; Mat) y pasto ángleton (Dichantium aristatum; Ang). Muestras representativas de los forrajes fueron analizadas por su contenido de nutrientes; las emisiones de metano de los forrajes solos y sus mezclas (90:10, 80:20 y 70:30, teniendo mayor participación las gramíneas) fueron medidas in vitro, mediante la técnica de producción de gas. La degradación de la materia seca se midió a las 24, 48, 72 y 96 h. Las leguminosas tuvieron mayores contenidos de proteína y grasa bruta; mientras que las gramíneas, mayores contenidos de fibra insoluble en detergente neutro y ácido y cenizas. La mayor producción de gas a las 96 h fue para Gui70-Leu30 (156 ml) y la menor fue Leu100 (P≤0,05; 121 ml). Para el sistema en confinamiento, la acumulación de gas de Ang70-Mat30 y Ang80-Mat20 a partir de a las 48 horas fueron superiores a los demás tratamientos (P<0,05). Las leguminosas mostraron mayores tasas de degradación que las gramíneas (P≤0,05). En ambos sistemas de producción no se encontraron diferencias significativas en la pérdida de energía digerida en forma de metano.

Climate change perception in recent decades has been growing as one of the major environmental issues of the XXI century. Methane emissions by rumen fermentation represent a loss of potentially usable energy. The objective of this study was to estimate methane emissions from various forages used in beef cattle diets. The diets evaluated corresponded to an intensive silvopastoral system (SSPi) with Leucaena (Leucaena leucocephala, Leu) and Guinea grass (Megathyrsus maximus; Gui) and a confinement system with Matarratón (Gliricidia sepium; Mat) and Angleton grass (Dichanthium aristatum; Ang). Representative forage samples were analyzed for nutrient contents. Methane emissions of individual forages and forage mixtures (90:10, 80:20, and 70:30, for grass:forage, respectively) were measured in vitro using the gas production technique. Dry matter degradation was measured at 24, 48, 72, and 96 h. Legumes had higher protein and crude fat content than grasses, while grasses had higher neutral detergent fiber, acid detergent fiber, and ash. The mixture composed by Gui70 - Leu30 had the highest gas production at 96 h (156 ml), while the lowest corresponded to Leu100 (P≤0.05; 121 ml). Regarding the confinement system results, gas accumulation after 48 hours by Ang70 - Mat30, and Ang80 - Mat20 were higher than the other treatments (P<0.05). Legumes had higher degradation rates than grasses (P≤0.05). No significant differences were found for methane losses between both production systems.

A percepção da mudança climática como um dos grandes problemas ambientais do seculo XXI está aumentando nas últimas décadas. A emisão de metano por fermentação ruminal é uma perda de energia potencialmente utilizavel. O objetivo foi estimar as emisões de metano de forragens utilizados em dietas para alimentar bovinos. As dietas avaliadas vieram de um sistema silvopastoril intensivo (SSPi) com leucaena (Leucaena leucocephala; Leu) e capim-mombaça (Megathyrsus maximus; Gui); e de confinamento com gliricídia (Gliricidia sepium; Mat) e a pastagem ángleton (Dichantium aristatum; Ang). Amostras representativas das forragens foram analisadas por seu conteúdo de nutrientes; as emissões de metano das forragens semeadas em monocultivo e misturadas (90:10, 80:20 e 70:30, tendo maior participação às gramíneas) foram medidas in vitro, mediante a técnica de produção de gás. A degradação da matéria seca estimou-se ás 24, 48, 72 e 96 h. As leguminosas tiveram maiores conteúdos de proteína e gordura bruta; enquanto as gramíneas tiveram maior fibra insolúvel em detergente neutro e azedo e cinzas. A maior produção de gás ás 96 h foi para Gui70-Leu30 (156 ml) e a menor foi Leu100 (P≤0,05; 121 ml). Para o sistema em confinamento, a acumulação de gás de Ang70-Mat30 e Ang80-Mat20 a partir das 48 horas foram superiores aos demais tratamentos (P<0,05). As leguminosas demonstraram maiores taxas de degradação que as gramíneas (P≤0,05). Nos dois sistemas de produção não se encontraram diferenças significativas na perda de energia digerida em forma de metano.