RESUMEN

The potential of soil organic carbon fractions for agroforestry systems (AFSs) is not well understood. Five distinct AFSs were tested for its impact on soil organic carbon fractionation, carbon index, and microbial activity in North Eastern Himalayas, India. The mean labile carbon (LC) ranged from 4.55 to 5.43 kg soil-1 across the land use systems. Napier system observed the lowest very labile carbon (VLC) 12.36 kg soil-1 in 60-75-cm depth. The mean non labile carbon (NLC) ranged from 15.67 to 16.83 g kg soil-1 across the land use. Highest less labile carbon (LLC) was observed in agri-horti-silviculture (AHS) followed by agri-silvi-horticulture (ASH) land use system. The black gram + mandarin + Alnus nepalensis land use recorded higher lability index (1.66) followed by maize + Schima wallichii (1.65) in 0-15-cm depth. Among the different land use systems, carbon pool index increased in all the depths over buckwheat + mandarin. The mean carbon management index (CMI) value ranged from 167.02 to 210.12 among the land use system. The mean CMI was highest in black gram + mandarin + Alnus nepalensis (210.12) followed by soybean + Ficus hookerii + guava (191.56), maize + Schima wallichii (281.71), and lowest in buckwheat + mandarin (167.02). Among the AFSs, black gram + mandarin + Alnus nepalensis showed greater amount of carbon pool index, lability index, and carbon management index and, hence, considered the best sustainable agroforestry system to sequester more carbon in the Sikkim Himalaya. Such system also retained more different organic carbon fractions. The mean CMI value ranged from 167.02 to 210.12 among AFSs. Acid phosphatase activity was more during the rainy season followed by winter and summer season. Similar trends were followed by the urease activity in all the three seasons. Overall conclusion from this investigation is that SOC fractions, carbon index, and microbial activity levels are strongly influenced by the prevailing agroforestry systems.

Asunto(s)

RESUMEN

This study tested the hypothesis that cocoa monoculture (MS) and cocoa-açai agroforestry systems (AFS) may influence the microbial community structure and populations of plant growth-promoting bacteria (PGPR). Accordingly, the aim was to analyze the microbial community structure and PGPR populations in different agroecosystems in the Brazilian Amazon. To achieve this, the rhizosphere microbial community of cocoa and açai plants in both Amazonian seasons (dry and rainy) was analyzed using culture-dependent (PGPR screening) and -independent methods [PCR-DGGE based on rrs, alp, nifH gene, and intergenic region (ITS) of fungi]. Concerning PGPR screening, out of 48 isolated bacterial strains, 25% were capable of siderophore production, 29% of mineralized organic phosphate, 8% of inorganic phosphate solubilization, and 4% of indole acetic acid production. Moreover, 17% of isolates could inhibit the growth of various phytopathogenic fungi. Statistical analyses of DGGE fingerprints (p < 0.05) showed that bacterial and fungal community structures in the rhizosphere were influenced by the seasons, supporting the results of the physicochemical analysis of the environment. Furthermore, as hypothesized, microbial communities differed statistically when comparing the MS and AFS. These findings provide important insights into the influence of climate and cultivation systems on soil microbial communities to guide the development of sustainable agricultural practices.

RESUMEN

BACKGROUND: This study explored the impact of Leucothyreus femoratus, a previously unreported folivorous pest in cacao cultivation, on cacao tree survival, development, and yield. The study was conducted in an experimental cacao plot in the Colombian plains, it featured 20 cacao genotypes in an agroforestry system, with plantain and Mexican sunflower providing temporary shade, and yopo offering permanent shade. RESULTS: We found an infestation rate of 2.9 ± 0.3 adult beetles per cacao tree. L. femoratus larvae were discovered in association with the roots of all plants within the agroforestry arrangement; however, yopo and plantain exhibited the highest incidence of root-feeding larvae among these associated plants. Interestingly, male and female L. femoratus displayed distinct leaf consumption patterns in the laboratory, with females consuming more foliage relative to their body weight. Moreover, field observations highlighted the detrimental impact of L. femoratus herbivory on cacao tree survival and growth, leading to leaf skeletonization, reduced plant height, and stem diameter. Trees with over 50% leaf consumption suffered more than 20% mortality. Additionally, herbivory negatively affected cacao yield, correlating higher leaf surface damage with a decrease in harvested pods. The study also identified varying antixenotic resistance in different cacao genotypes, with some consistently displaying resistance while others showed variable levels during tree establishment and production stages. CONCLUSION: This research underscores the significant role of L. femoratus as a cacao pest, emphasizing its adverse effects on cacao tree survival, development, and yield. Consequently, implementing effective control measures is vital for ensuring sustainable cacao cultivation. © 2023 Society of Chemical Industry.

Asunto(s)

RESUMEN

Land use change is one of the greatest threats to soil biodiversity and ecological functions; however, how such a transition affects soil carbon (C) and nitrogen (N) dynamics driven by fungal communities at the aggregate level remains unclear. Here, we explored the variation in soil C and N pools, specific enzyme activities and fungal communities and functional guilds within three aggregate sizes (megaaggregates, > 2 mm; macroaggregates, 0.25-2 mm; microaggregates, < 0.25 mm) in a natural forest, 12- and 24-year-old rubber monocultures and corresponding agroforestry systems in tropical China. Tropical forest conversion to rubber monocultures generally reduced C and N pools in all aggregates, while agroforestry systems decreased microbial biomass C and N. Carbon- and N-degrading enzyme activities responded differently to forest conversion and were enhanced in agroforestry systems. The levels of C and N pools and their related enzyme activities increased as the aggregate size decreased. Moreover, fungal compositional shifts in dominance from copiotrophic Ascomycota and Basidiomycota (r-strategists) into oligotrophic Zygomycota (K-strategists) were noted following forest conversion, resulting in more pathogenic fungi at the expense of saprotrophic and arbuscular mycorrhizal fungi. Pathogenic fungi were greatly inhibited due to abundant Mortierella after the establishment of 12-year-old agroforestry systems. The diversity of saprotrophic fungi was the highest in microaggregates. Regardless of land use type, aggregate-associated C and N pools, especially DOC, MBC, NO3--N and DON in microaggregates, were interactively mediated by functional guilds of fungi, which was primarily driven by soil pH. These results highlight the importance of fungal functional guilds in determining C and N dynamics at the aggregate level and provide insights into the sustainable management of cash tree plantations.

Asunto(s)

RESUMEN

In Africa, banana is mainly produced by smallscale farmers under complex production systems for both home consumption and income generation. Low soil fertility continually constraints its production and farmers are embarking on emerging technologies such as improved fallow, cover crops, integrated soil fertility management, agroforestry with fast growing tree species to address this challenge. This study aims at assessing the sustainability of grevillea-banana agroforestry systems by investigating the variability in their soil physico-chemical properties. Soil samples were collected in banana sole stands, Grevillea robusta sole stands and grevillea-banana intercrops in three agro-ecological zones during the dry and rainy seasons. Soil physico-chemical properties significantly differed among agroecological zones, cropping systems and between seasons. Soil moisture, total organic carbon (TOC), P, N, Mg decreased from the highland to the lowland zone, through the midland zone whereas soil pH, K and Ca showed the opposite trend. Soil bulk density, moisture, TOC, NH4+-N, K and Mg were significantly higher in the dry season compared to the rainy season but total N was higher in the rainy season. Intercropping banana with grevillea trees significantly decreased soil bulk density, TOC, K, Mg, Ca and P. Soils under banana sole stands accumulated higher potassium, magnesium, calcium, phosphorus with a higher soil bulk density and pH compared to grevillea-banana intercrops and grevillea sole stands. This suggests that intercropping banana and grevillea trees increases the competition for these nutrients and requires careful attention for the optimization of their interactive benefits.

RESUMEN

Gliricidia (Gliricidia sepium) is a tree legume that has great potential for use in agriculture because of its multiple-use characteristics. However, there is little information in the literature about the effect of agrisilvicultural systems on nitrogen (N) cycling. This study evaluated the effect of densities of gliricidia on N cycling under an agrisilvicultural system. The treatments were composed of different densities of gliricidia: 667, 1000 and 1333 plants ha-1, with a fixed spacing of 5 m between the alleys. The efficiency of N use was investigated by using the 15N isotope tracer. In each plot, a transect perpendicular to the tree rows was established in two positions: (i) in the corn (Zea mays) row adjacent to the trees, and (ii) in the corn row in the center of the alley. The N fertilizer recovery efficiency ranged from 39% in the density of 667 plants ha-1 to 89% with 1000 plants ha-1. The effect of gliricidia on the N uptake by corn was higher in the central position of the alley with 1000 plants ha-1. The agrisilvicultural system with 1000 plants ha-1 was highly efficient in the recovery of mineral N, representing an excellent option for integrated production systems in tropical regions.

RESUMEN

The under-forest economy in the agroforestry system can improve land use efficiency, protect ecological environment, and promote arable land sustainable development. However, the effects of soil moisture in the forest and irrigation strategies on the healthy growth of intercropping crops are still incomplete. Here, considering the organic Panax notoginseng cultivated under pine forests (PPF) as the research object, we explored the effects of different soil moisture on the physiological state, yield, quality and disease occurrence of PPF. Our results suggested that 80-85% and 95-100% field capacity (FC) treatments were more conducive to increased photosynthetic rate and biomass accumulation of PPF, but 50-55% and 65-70% FC treatments were more conducive to the accumulation of saponins in PPF leaves. Notably, the root rot index of PPF was highest under 95-100% FC (19.51) treatment, significantly higher than that under 65-70% FC (8.44) and 80-85% FC (10.21) treatments. Further, the rhizosphere microorganisms of PPF under different soil moisture treatments were sequenced, and the sequencing data analysis revealed that high soil moisture (95-100% FC) could destroy the microbial diversity balance and cause the accumulation of pathogens (Fusarium oxysporum and Ilyonectria radicicola), leading to a high incidence of root rot. The incidence of PPF root rot was negatively correlated with rhizosphere microbial diversity. Overall, our results highlight that the quantitative irrigation (80-85% FC) is conducive to maintaining the balance between yield, saponin content and disease occurrence of PPF, providing a practical basis for PPF irrigation strategy and promoting the sustainable development of PPF agroforestry system.

Asunto(s)

RESUMEN

Intercropping achieved through agroforestry is increasingly being recognized as a sustainable form of land use. In agroforestry, the roots of trees and crops are intermingled, and their interactions and the production of exudates alter the soil environment and soil microbial community. Although tree-crop interactions vary depending on the stand age of the trees, how stand age affects beneficial microorganisms, including arbuscular mycorrhizal fungi (AMF), and whether changes in soil microorganisms feed back on crop growth in agroforestry systems are unknown. We therefore conducted a long-term field study to compare changes in the soil microbial and AMF communities in a jujube/wheat agroforestry system containing trees of different stand ages: 3-year-old jujube, 8-year-old jujube, and 13-year-old jujube. Our results showed that by changing soil moisture and available phosphorus content, the stand age of the trees had a significant effect on the soil microbial and AMF communities. Soil moisture altered the composition of soil bacteria, in particular the proportions of Gram-positive and Gram-negative species, and available phosphorus had significant effects on the AMF community. A network analysis showed that older stands of trees reduced both AMF diversity and network complexity. An ordinary least squares regression analysis indicated that AMF diversity, network complexity, and stability contributed to wheat yield. Finally, structural equation modeling showed that changes in edaphic factors induced by tree age brought about significant variation in the soil microbial and AMF communities, in turn, affecting crop growth. Our study highlights the crucial roles of soil microorganisms, in particular AMF, in supporting plant growth in agroforestry systems as well as the need to consider stand age in the establishment of these systems.

RESUMEN

Land-use conversion affects the composition and assembly of plant-associated microbiomes, which in turn affects plant growth, development, and ecosystem functioning. However, agroforestry systems, as sustainable land types, have received little attention regarding the dynamics of different plant-associated microbes. In this study, we used high-throughput sequencing technology to analyze the assembly mechanisms and the driving factors of pine- and Panax notoginseng (P.n.)-associated microbiomes during the conversion of different pine forests (Pinus kesiya var. langbianensis and Pinus armandii) into P.n.-pine agroforestry systems. The results showed that the conversion of pure pine forest into P.n.-pine agroforestry systems significantly altered the diversity of pine-associated fungi rather than the community structure, and the community structure of P.n.-associated fungi rather than the diversity. Additionally, plant-associated fungi were more responsive to land-use change than bacteria. Main effect analysis revealed that compartment rather than genotype was the driving factor of pine- and P.n.-associated microbiomes, but P.n. cultivation also significantly affected the assembly of pine-associated microbiomes. In addition, there was a transfer of P.n. endophytes to pine trees in agroforestry systems and the beneficial microbiomes (Massilia, Marmoricola, Herbaspirillum, etc.) were enlarged in pine roots. Therefore, the diversity of the assembly mechanisms of P.n.- and pine-associated microbiomes played an important role in the P.n.--pine agroforestry systems and were the basis for the sustainable development of the P.n.--pine agroforestry systems.

RESUMEN

Background: Cocoa is an important tropical tree crop that is mainly cultivated in agroforestry systems (AFS). This system, known as cabruca in northeastern Brazil, holds promise to reconcile biodiversity conservation and economic development. However, since cocoa AFS alters forest structure composition, it can affect litter dynamics in riparian zones and streams. Thus, our objective was to determine litter inputs and standing stocks in riparian zones and streams under three types of forest: managed cocoa AFS, abandoned cocoa AFS, and secondary forest. Methods: We determined terrestrial litter fall (TI), vertical (VI) and lateral (LI) litter inputs to streams, and litter standing stocks on streambeds (BS) in the Atlantic Forest of northeastern Brazil. Litter was collected every 30 days from August 2018 to July 2019 using custom-made traps. The litter was dried, separated into four fractions (leaves, branches, reproductive organs, and miscellaneous material) and weighed. Results: Terrestrial litter fall was similar in all forests, ranging from 89 g m-2 month-1 in secondary forest (SF) to 96 g m-2 month-1 in abandoned cocoa AFS (AC). Vertical input were higher in AC (82 g m-2 month-1) and MC (69 g m-2 month-1) than in SF (40 g m-2 month-1), whereas lateral input were higher in MC (43 g m-2 month-1) than in AC (15 g m-2 month-1) and SF (24 g m-2 month-1). Standing stocks followed the order SF > AC > MC, corresponding to 425, 299 and 152 g m-2. Leaves contributed most to all litter fractions in all forests. Reproductive plant parts accounted for a larger proportion in managed AFS. Branches and miscellaneous litter were also similar in all forests, except for higher benthic standing stocks of miscellaneous litter in the SF. Despite differences in the amounts of litter inputs and standing stocks among the forests, seasonal patterns in the abandoned AFS (AC) were more similar to those of the secondary forest (SF) than the managed AFS, suggesting potential of abandoned AFS to restore litter dynamics resembling those of secondary forests.

Asunto(s)

RESUMEN

The family Tuckerellidae, or peacock mites, is a monogeneric group comprising approximately 32 species, which are usually collected from the fruits or woody parts of their host plants. Fruits and branchlets of mamey, Mammea americana L. (Calophyllaceae) trees in north-western Peru were sampled for peacock mites throughout spring and summer for two consecutive years. This is the first record of Tuckerella pavoniformis (Ewing) (Acari: Tuckerellidae) feeding on mamey. Aggregations of mites were much higher and more common on the fruit epicarps than on branchlets. Recommendations for the development of an Integrated Pest Management strategy for this peacock mite are included.

RESUMEN

In coffee, fruit production on a given shoot drops after some years of high yield, triggering pruning to induce resprouting. The timing of pruning is a crucial farmer's decision affecting yield and labour. One reason for fruit production drop could be the exhaustion of resources, particularly the non-structural carbohydrates (NSC). To test this hypothesis in a Coffea L. arabica agroforestry system, we measured the concentrations of NSC, carbon (C) and nitrogen (N) in leaves, stems and stumps of the coffee plants, 2 and 5 years after pruning. We also compared shaded vs full sun plants. For that purpose, both analytical reference and visible and near infrared reflectance spectroscopy (VNIRS) methods were used. As expected, concentrations of biochemical variables linked to photosynthesis activity (N, glucose, fructose, sucrose) decreased from leaves to stems, and then to stumps. In contrast, variables linked more closely to plant structure and reserves (total C, C:N ratio, starch concentration) were higher in long lifespan organs like stumps. Shading had little effect on most measured parameters, contrary to expectations. Concentrations of N, glucose and fructose were higher in 2-year-old organs. Conversely, starch concentration in perennial stumps was three times higher 5 years after pruning than 2 years after pruning, despite high fruit production. Therefore, the drop in fruit production occurring after 5-6 years was not due to a lack of NSC on plant scale. Starch accumulation in perennial organs concurrently to other sinks, such as fruit growth, could be considered as a 'survival' strategy, which may be a relic of the behaviour of wild coffee (a tropical shade-tolerant plant). This study confirmed that VNIRS is a promisingly rapid and cost-effective option for starch monitoring (coefficient of determination for validation, R2val = 0.91), whereas predictions were less accurate for soluble sugars, probably due to their too similar spectral signature.

Asunto(s)

RESUMEN

BACKGROUND: In the parkland agroforestry system of northern Uganda, smallholder farming households rely on a diversity of plant species to fulfil their nutritional requirements, many of which also serve a range of medicinal, cultural, and livelihood functions. The purpose of the study was to assemble an inventory of indigenous plant species used as food in four districts within the Aswa River catchment of northern Uganda, and to document their utilization and management by rural communities. METHODS: From July 1999 to August 2000, a series of 61 community-based focus group discussions on the utilization of plant biodiversity were conducted in the vernacular language at 34 sites in four districts of northern Uganda, with participation by key informants self-selected on basis of their technical knowledge and personal interest. Of these, 232 respondents subsequently contributed to a collection of herbarium specimens, which were submitted to the Makerere University Herbarium for identification. On receipt of each specimen collected, a structured interview was conducted to document the botanical, ecological, seasonal, and alimentary attributes of each identified taxon, and details of its processing and utilization by the community from which it was obtained. The data analysis was undertaken during 2019 and 2020, including statistical tests to assess the relative importance of the cited taxa using the Relative Importance Index (RI), and to determine the similarity of edible plant use between the four cultures using the Jaccard Index of similarity (JI). RESULTS: Key informant interviews yielded 1347 use reports (URs) for 360 identified specimens of 88 indigenous edible plant species. The data describes patterns of use of indigenous edible plants of four cultures of the Aswa River catchment of northern Uganda. RI scores ranged from 0.93 to 0.11, with fruit trees occupying the top 25 taxa (RI 0.45 and above). Jaccard similarity scores ranged from 25.8% between Lango and Acholi, to 15.8% between Acholi and Ethur, indicating that cultural factors appear to be more significant than shared ancestry as determinants of cultural similarity of plant use. CONCLUSIONS: The data constitute an inventory of on-farm plant species, including cultivated, semi-cultivated, and wild plants, integrated into a parkland agroforestry system in which useful trees and other plant species are sustained and managed under cultivation. Agricultural and on-farm plant biodiversity may be seen as a food security resource, and a nutritional buffer against increasing risks and stressors on low-input smallholder agriculture. Further studies should assess the intra-species biodiversity of these resources, with respect to farmer-valued traits and vernacular (folk) classification systems.

Asunto(s)

RESUMEN

Evaluating how decomposition rates and litter nutrient release of different litter types respond to changes in water conditions is crucial for understanding global carbon and nutrient cycling. However, it is unclear how decreasing water affects litter mixture interactions for the maize-poplar system in arid regions. Here, the responses of the litter decomposition process and litter mixture interactions in the agroforestry system to changes in water conditions (control, light drought, and moderate drought) were tested. Moderate drought significantly decreased the decomposition rate for poplar leaf and mixed litters, and decomposition rate was significantly reduced for maize straw litter in light and moderate drought stress. The mass loss rates of maize straw and mixed litters were significantly higher than that of the poplar leaf litter under drought conditions, but there was no significant difference among the three litter types in the control. There was no interaction between mass loss of the mixed litter in the control and light drought conditions, and the litter mixture interaction showed nonadditive synergistic interactions under moderate drought. In terms of nutrient release, there was also no interaction between litter mixture with nitrogen and carbon, but there was antagonistic interaction with potassium release under the light drought condition. Our results demonstrate that drought conditions can lead to decreasing decomposition rate and strong changes in the litter mixture interactions from additive effects to nonadditive synergistic effects in moderate drought. Moreover, light drought changed the mixture interaction from an additive effect to an antagonistic interaction for potassium release.

RESUMEN

Resumen El cambio climático, ocasionado por el incremento en la concentración de gases efecto invernadero (GEI), genera alteraciones en el clima del planeta, aumentando la temperatura media global, lo que afecta patrones de precipitación. El área de estudio se ubicó en el Municipio de Yopal, corregimiento Tacarimena, compuesta por ocho veredas, la cual presenta clima cálido - húmedo con promedio de precipitación anual de 2270 mm; temporada seca de diciembre-marzo y lluviosa de abril-noviembre y alturas inferiores a 380 m. En concordancia con la necesidad del desarrollo bajo en carbono, la presente investigación estima la biomasa arriba y abajo del suelo y con éstas el carbono total almacenado en siete sistemas de uso del suelo: 1) plátano con sombrío (SAF+ plátano), 2) cacao con sombrío (Ca+S), 3) cítricos (C), 4) sistema silvopastoril bajo (SSPB), 5) sistema silvopastoril alto (SSPA), 6) bosques de galería (BG), y 7) mata de monte (MM). Se trabajó con diseño experimental completamente al azar con cinco repeticiones, para un total de 35 unidades experimentales. Se establecieron parcelas temporales de muestreo, tomando datos en 832 árboles de 66 especies botánicas. Se estimó la biomasa arriba del suelo mediante modelos alometricos, utilizando datos de campo (diámetro a la altura del pecho dap y la altura total). La biomasa abajo del suelo (raíces) se estimó empleando el modelo general para bosques tropicales. Todos los usos del suelo en estudio ofrecen el servicio ecosistémico de captura de carbono, siendo el BG y la MM los de mayor carbono, mientras que el SAF+plátano almacenó la menor cantidad de carbono. Potenciales cambios de sistemas productivos a sistemas forestales (BG y MM) implican una ganancia de carbono (adicionalidad), mientras que los cambios contrarios, es decir deforestación, representan emisiones de CO2. Estos resultados son claves para la orientación a políticas y proyectos de captura de carbono.

Abstract Climate change caused by increased greenhouse gas (GHG) concentration causes alterations in the planet's climate and increases the average global temperature, thereby affecting rainfall patterns. This study's target area was the town of Tacarimena in the municipality of Yopal; it has eight rural areas. The area is located around 380 masl and has a warm, humid climate, a mean annual rainfall of 2,270 mm, a dry season between December and March and a rainy season from April to November. This research has estimated seven land-use systems' above- and below-ground biomass and total carbon storage in line with a low-carbon development policy: 1) plantain with shade (SAF + plantain), 2) cocoa with shade (Ca + S), 3) citrus (C), 4) low-lying silvopastoral system (LSS), 5) high-lying silvopastoral system (HSS), 6) gallery forest (GF) and 7) bush (B). A completely randomised experimental design with five repetitions was used, giving 35 experimental units. Temporary sampling plots were established for taking information regarding 832 trees from 66 botanical species. Allometric models were used for estimating above-ground biomass using field data/measurements (diameter at breast height (DBH) and total height (TH). A general tropical forest model was used for estimating below-ground biomass. All the land-use systems being studied had the essential ecosystem service of carbon capture/CO2 sequestration where GF and B had the highest carbon storage; on the contrary, SAF + plantain stored the lowest amount of carbon. Changing from production to forestry systems (GF and B) implies increased carbon capture (additionality), whereas the opposite (i.e. deforestation) represents CO2 emission. Such results represent a key input for policy design and carbon capture projects.

Resumo A mudança climática, causada pelo aumento da concentração de gases de efeito estufa (GEEs), gera alterações no clima do planeta e um aumento na temperatura média global, afetando os padrões de precipitação. A área de estudo foi localizada no município de Yopal, distrito Tacarimena, composto por oito vilarejos, que tem um clima quente - úmido com precipitação anual média de 2.270 mm, além de uma estação seca de dezembro a março e uma estação chuvosa entre abril e novembro. De acordo com a necessidade de desenvolvimento baixo em carbono, esta pesquisa estima a biomassa acima e abaixo do solo e com eles o total de carbono armazenado em sete sistemas de uso da terra: 1) banana com sombra (SAF + banana), 2) cacau sombreado (Ca + S), 3) cítricos (C), 4) sistema silvopastoril baixo (SSPB), 5) sistema silvopastoril alto (SSPA), 6) floresta riparia (BG), e 7) fragmento de floresta (MM). Desenvolveu-se um desenho experimental inteiramente casualizado com cinco repetições, totalizando 35 unidades experimentais. Parcelas temporárias de amostragem foram estabelecidas, tomando dados de 832 árvores de 66 espécies botânicas. A biomassa acima do solo foi estimada com modelos alométricos, inserindo os dados de campo: diâmetro à altura do peito (dap) e a altura total. A biomassa abaixo do solo foi estimada usando um modelo geral para florestas tropicais. Todos os usos da terra em estudo oferecem o serviço ecossistêmico de captura de carbono, sendo BG e MM os que apresentam o maior carbono, enquanto que SAF + banana armazenou a menor quantidade de carbono. Mudanças potenciais de sistemas de produção para sistemas florestais (BG e MM) implicam em ganho de carbono (adicionalidade), entanto que as mudanças opostas, como o desmatamento, representam emissões de CO2. Esses resultados são chaves para orientar políticas e projetos de captura de carbono.

RESUMEN

Land clearing for agricultural use is a primary driver of biodiversity loss and fragmentation of natural ecosystems. Restoring natural habitat connectivity by retaining quality habitats and increasing on-farm tree cover contributes to species' mobility and persistence in agricultural landscapes. Nonetheless, remarkably few studies have quantified the impacts of on-farm practices for species' mobility measured as functional connectivity within the context of farm and broader spatial levels of landscape organization. We tested how adding and removing trees in different configurations on a farm comprised of coffee plantations and cattle pastures can help evaluate species' mobility at the farmscape level (an area comprising the farm plus a 1.5 km buffer area). We coupled bird capture data and scenario modeling to assess species mobility of five neotropical bird species with distinct life history characteristics representing a gradient of forest dependency. We used seven years of mist-netting data to estimate species habitat affinity and to predict species mobility using the Circuitscape model across a 4371 ha farmscape in Costa Rica. Circuitscape allowed us to estimate changes in movement probability and relative changes in resistance to movement that species experience during dispersal (measured as resistance distance and passage area through which species can move) under four farmscape management scenarios. The four land-use scenarios included: (a) the 2011 farmscape land-use composition and configuration, b) converting all existing live fences to post-and-wire fence lines in the farm c) converting simplified coffee agroforests to multistrata coffee agroforests in the farm, and d) placing multistrata live fences around the perimeter of every parcel and roads on the farm. Model results suggest that existing multistrata live fences maintain the sporadic movement of all five species irrespective of forest dependence. Likewise, adding multistrata live fences around individual fields presents a more efficient strategy for increasing species mobility than multistrata coffee agroforestry systems in the assessed farmscape, by doubling the passage areas available to all species, although it created labyrinths with "dead-ends" for two species. While retaining large habitat patches remains important for conservation, managing on-farm connectivity complements these efforts by increasing movement probability and reducing dispersal resistance for forest-dependent bird species.

Asunto(s)

RESUMEN

Resumen Con el propósito de avanzar en la valoración de las propiedades químicas, físicas y biológicas como indicadores de calidad del suelo en un sistema agroforestal, se evaluaron tres sistemas de uso en suelos de terraza alta ubicados en el C.I La Libertad de Agrosavia: bosque, sistema agroforestal (SAF) y pradera. Se tomaron muestras de suelo a dos profundidades 0-10 cm (P1) y 10-20 cm (P2). Se midieron variables químicas y físicas, se hizo recuento microbiano de hongos, bacterias, actinomicetos y mesoinvertebrados, estos se identificaron a nivel de familia y especie. Inicialmente, se realizó análisis descriptivo de los datos y se interpretaron de acuerdo con los valores de referencia reportados. El análisis estadístico se realizó por medio de Análisis de Componentes Principales (ACP), análisis de varianza y prueba de comparación de medias de Duncan (para lo cual se utilizaron los software estadísticos R versión 3.1.2 (paquete ADE4 1.4.5) e INFOSTAT 2014I). Se seleccionaron las variables químicas pH, aluminio intercambiable (AlH), fósforo (P), calcio (Ca), magnesio (Mg), potasio (K), boro (B), azufre (S), sodio (Na), zinc (Zn), capacidad de intercambio catiónico efectiva (CICE) y las variables fisicas conductividad hidráulica (CH), densidad aparente (DA), mesoporosidad (MES), porosidad total (PT), saturación (SAT), capacidad de campo (CC), humedad disponible (HD), microporosidad (MIC), punto de marchitez permanente (PMP), porcentaje de arena y arcilla, que permiten separar los sistemas en cuanto a la calidad del suelo. En el SAF se encontró moderada calidad química representada por altos valores de pH(5,30), bajo AlH (1,02 Cmol/kg), bajos contenidos de Ca en P1 (1,49 Cmol/kg) y P2 (0,71 Cmol/kg), bajo Mg en P1(0,49 Cmol/kg) y P2(0,21 Cmol/kg) y, los mayores valores encontrados de S(13,08 mg/kg) y Zn(0,70 mg/kg) en P2. A su vez, el SAF mostró baja calidad física con valores de DA de 1,34 g/cm3 en P1 y 1,46g/cm3 en P2. Las variables biológicas no contribuyeron a la diferenciación entre sistemas, sin embargo, el bosque arrojó un mayor número de actinomicetos y hongos micorrizicos arbusculares (HMA) asociados a una mayor asimilación de nutrientes como el P.

Abstract In the evaluation of the chemical, physical and biological properties as soil quality indicators for agroforestry systems, three systems of land use were valued. These systems are located in high terrace soils in the La Libertad de Agrosavia were evaluated: forest, system agroforestry (SAF) and grassland. Soil samples were taken at two depths 0-10 cm (P1) and 10-20 cm (P2). Chemical and physical variables were measured, microbial counts were made of fungi, bacteria, actinomycetes and mesoinvertebrates. These organism were identified at family and species level. Initially, a descriptive analysis of the data was performed and interpreted according to the reported reference values. The statistical analysis was carried out through Principal Component Analysis (PCA), variance analysis and Duncan's mean comparison test (for which statistical software R version 3.1.2 (package ADE4 1.4.5) and INFOSTAT were used. 2014I). Chemical variables were selected: pH, exchangeable aluminum (AlH), phosphorus (P), calcium (Ca), magnesium (Mg), potassium (K), boron (B), sulfur (S), sodium (Na), zinc ( Zn), effective cation exchange capacity (CICE) and the physical variables hydraulic conductivity (CH), bulk density (DA), mesoporosity (MES), total porosity (PT), saturation (SAT), field capacity (CC), available humidity (HD), microporosity (MIC), permanent wilting point (PMP), percentage of sand and clay, which allow to separate the systems in terms of soil quality. In the SAF, moderate chemical quality was found, represented by high pH values ​​(5.30), low AlH (1.02 Cmol / kg), low contents of Ca in P1 (1.49 Cmol / kg) and P2 (0, 71 Cmol / kg), under Mg in P1 (0.49 Cmol / kg) and P2 (0.21 Cmol / kg) and, the highest values ​​found of S (13.08 mg / kg) and Zn (0.70 mg / kg) in P2. In turn, the SAF showed low physical quality with DA values ​​of 1.34 g / cm3 in P1 and 1.46 g / cm3 in P2. The biological variables did not contribute to the differentiation between systems, however, the forest showed a greater number of actinomycetes and arbuscular mycorrhizal fungi (AMF) associated with greater assimilation of nutrients such as P.

Resumo Com o objetivo de avançar na avaliação das propriedades quimicas, físicas e biológicas como indicadores de qualidade do solo em um sistema agroflorestal, foram avaliados os siguientes sistemas de uso do solo no CI La Libertad de Agrosavia: Floresta, Sistema agroflorestal (SAF) e Praderia. As amostras de solo foram coletadas em duas profundidades de 0-10 cm (P1) e 10-20 cm (P2). Variáveis ​​químicas e físicas, micróbios de fungos, bactérias, actinomicetos e mesoinvertebrados foram identificados, estes foram identificados em nível de família e espécie. Inicialmente, foi realizada uma análise descritiva dos dados e a concordância foi interpretada com os valores de referência reportados. A análise estatística foi realizada no meio da análise dos componentes principais (PCA), a análise da variância e o teste de comparação dos meios de Duncan (para o qual é utilizado o software estatístico R versão 3.1.2 ( pacote ADE4 1.4.5) e INFOSTAT 2014I). química variáveis ​​de pH, permutável alumínio (AlH), fósforo (P), cálcio (Ca), magnésio (Mg), potássio (K), boro (B), enxofre (S), sódio (Na), foram seleccionados zinco ( Zn), capacidade de permuta catiónica eficaz (ICC) e da condutividade hidráulica variável (CH), a densidade a granel (BD), mesoporosidade (MES), a porosidade total (PT), a saturação (SAT), a capacidade de campo (CC), humidade disponível (HD), microporosidade (MIC), ponto de execução permanente (PMP), porcentagem de areia e argila, que permite separar os sistemas em termos de qualidade do solo. No SAF há uma qualidade química moderada representada por altos valores de pH (5,30), baixo AlH (1,02 Cmol / kg), baixos teores de Ca em P1 (1,49 Cmol / kg) e P2 (0, 71 Cmol / kg), sob Mg em P1 (0,49 Cmol / kg) e P2 (0,21 Cmol / kg), os maiores valores encontrados de S (13,08 mg / kg) e Zn (0,70 mg / kg) em P2. Por sua vez, o SAF apresentou uma qualidade física com valores de DA de 1,34 g / cm3 em P1 e 1,46 g / cm3 em P2. As variáveis biológicas não contribuem para a diferenciação entre os sistemas, no entanto, os solos da floresta mostraram um maior número de actinomicetos e fungos micorriza arbusculares (HMA) associada a uma maior absorção de nutrientes, tais como P.

RESUMEN

Assessment of crop loss due to multiple diseases and pests (D&P) is a necessary step in designing sustainable crop management systems. Understanding the drivers of D&P development and yield loss helps identify leverage points for crop health management. Crop loss assessment is also necessary for the quantification of D&P regulation service to identify promising systems where ecosystem service provision is optimized. In perennial crops, assessment of crop losses due to D&P is difficult, as injuries can affect yield over years. In coffee, one of the first perennials in which crop loss trials were implemented, crop losses concurrent with injuries were found to be approximately 50% lower than lagged losses that originated following the death of productive branches due to D&P. Crop losses can be assessed by field trials and surveys, where yield reduction factors such as the number of productive branches that have died are quantified, and by modeling, where damage mechanisms for each injury are considered over several years.

Asunto(s)

RESUMEN

Objetivou-se validar o método de análise de dados bioacústicos na descrição do comportamento em pastejo de novilhas em área de integração lavoura-pecuária (iLP) e floresta (iLPF). Foram utilizadas oito novilhas Girolando (¾Holandês x »Gir) com média de 25±6,8 meses de idade e 268±83kg de peso vivo (PV), distribuídas em delineamento crossover 2x2 (dois sistemas x dois períodos de avaliação). A coleta de dados para análise bioacústica foi realizada utilizando-se gravadores MP3. Esses dados foram analisados pelo software Audacity® para identificação das atividades de pastejo, ruminação e ócio. Concomitantemente, o comportamento também foi avaliado pelo método de observação visual, realizado no período de 8 até 16 horas, em intervalos de 15 minutos. Não houve diferença (P>0,05) entre médias dos tempos (minutos) de pastejo, ruminação e ócio registrados pelos métodos de bioacústica e avaliação visual, sendo, respectivamente, 127 vs. 137; 122 vs. 113 e 238 vs. 216, no sistema iLP, e 134 vs. 103; 130 vs. 165 e 233 vs. 203, no sistema iLPF. Por meio desses resultados, foi possível concluir que o método da bioacústica é uma importante ferramenta para avaliar o comportamento de pastejo em diferentes sistemas de produção a pasto, com a vantagem de possibilitar o registro de atividades durante o período noturno, além de maior praticidade e precisão do que o método observacional.(AU)

Aiming to validate the analysis of bioacoustic data for describing grazing behavior of heifers in integrated crop, livestock (ICL) and forestry (ICLF) systems. Eight 25±6.8 month-old Girolando (¾Holstein × »Gir) heifers with 268±83kg of live weight (LW) were distributed in 2x2 crossover design (two systems x two evaluation periods). Data collection for bioacoustic analysis was done with MP3 recorders. These data were analyzed by Audacity® software for identification of the activities of grazing, rumination, and resting. Concomitantly, behavior was also analyzed by the method of visual observation from 8AM to 4PM in intervals of 15 minutes. There was no difference (P>0.05) between the methods of bioacustic and visual observation considering the means of time (minutes) of grazing, rumination, and resting, respectively: 127 vs. 137; 122 vs. 113; and 238 vs. 216 in ICL system and; 134 vs. 103; 130 vs. 165 and 233 vs. 203 in ICLF system. In conclusion, the bioacustic method is a tool that can be useful for evaluating bovine grazing behavior within different grazing systems, with the advantage of allowing report of activities during the night with higher practicality and precision than the visual observation method.(AU)

Asunto(s)

RESUMEN

El cacao (Theobroma cacao L.) es nativo de América del Sur y representa uno de los recursos «bioculturales¼ más significativos de Mesoamérica, ya que es una región donde se domesticó y tuvo relevancia como bebida ritual y como moneda en muchas culturas prehispánicas hasta la llegada de los españoles, quienes difundieron su uso en el mundo y lo convirtieron en una de las mercancías «commodity¼ más consumidas. Mediante este trabajo se propone una alternativa para atender la problemática de las plantaciones a través de la introducción de una diversidad amplia de cultivares de cacao en sistemas agroforestales tradicionales, en sinergia con la inoculación de bacterias edáficas fijadoras de nitrógeno y solubilizadoras de fósforo insoluble. En una parcela agroforestal tradicional se introdujeron plantas de cacao injertadas de cuatro cultivares y se dispusieron 3 tratamientos: aplicación de biofertilizante, aplicación de fertilizante químico y testigo. Se registraron la altura, el diámetro basal, el número de hojas y el número de ramas a los 2 y 12 meses, y se caracterizó la población de microorganismos asociada alrededor del tallo bajo la copa de las plantas. Los resultados de crecimiento muestran un buen potencial para los 4 cultivares estudiados y se observó que la biofertilización generó efectos significativos en algunos de los indicadores de crecimiento de las plantas de cacao. Así, las asociaciones vegetales en un sistema agroforestal podrían ser favorables para potenciar el desarrollo de frutos y resistencia a plagas y enfermedades.

Cocoa plant (Theobroma cacao L.) is native from South America and it represents one of the most significant "bio-cultural" resources of Mesoamerica, since it is a region where it was domesticated and had a relevance as ritual drink and as currency in many pre-hispanic cultures until the arrival of the Spaniards who spread its use worldwide, and became it one of the most consumed commodity goods. Through this research, an alternative is proposed to address the problem of cultivars through the introduction of a wide variety of cocoa plants in traditional agroforestry systems, in synergy with the inoculation of nitrogen-fixing and insoluble phosphor solubilizing edaphic bacterial consortia. Four cultivars of improved grafted cocoa plants were introduced in a traditional agroforestry plot and three fertilization treatments were applied: application of biofertilizer, application of chemical fertilizer and control. Measurements of height, stem diameter, number of leaves and branches were recorded at 2 and 12 months after planting and rhizosphere microbial populations were characterized. Growth results showed good potential for all studied cultivars and it was observed that biofertilization foresees significant effects in some of the growth indicators of cocoa plant. Thereby, plant associations in an agroforestry system could be favorable to promote fruit development and resistance to pests and diseases.

Asunto(s)