Dataverse World Agroforestry (ICRAF)
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Replication data for: Effect of diagonal cut surface length on graft success and growth of mangifera indica, Persia americana, and Prunus persica
No full textGrafting has been a common propagation method in many fruit trees to achieve fruiting precocity. Its success has depended on proper alignment of parenchymatous tissues of both scions and their respective rootstocks. Although grafting has been practiced for a long time, the right or ideal length of a diagonal cut surface that promotes proper alignment of vascular bundles of both graft partners to ensure fast graft-take and eventually graft success have not been investigated. An experiment was carried out on mango, avocado, and peach trees with an objective of establishing suitable or correct length of a diagonal cut surface when grafting (splice method) to improve graft success. Diagonal cut surface lengths applied to both scions and rootstocks included 5 mm, 10 mm, 20 mm, 40 mm, 60 mm, 80 mm, or 100 mm with at least three grafters treated as a random component. A significant difference (P less than 0.0001) was found among the diagonal cut surface lengths and over 80% of graft success was obtained with 40- to 100-mm diagonal cut surface lengths, especially for mango. Significant differences (P less than 0.0001) were also obtained in shoot length and stem diameter size (thickness) for all tree crops studied and also for number of leaves except for avocado plants. It is concluded that improved graft success can be achieved with a diagonal cut surface length of 40 mm long with the need for a few grafting strips
The institutional economics of sustainable land management
No full textThe study looked at the general characteristics of a household, the household assets and livelihood indicators, natural resource management ractives in the household, farm production per plot, sources of income of the household and the corresponding expenses, sustainable land amanagement practises and institutions involed in sustainable mangement practises. the dat was collected in vivhiga district (Western Kenya) and involved 320 small holder farmer households. the data focussed on the intituitonal economics of sustainable land management practise
Replication data for: Ethnobotany, propagation and conservation of medicinal plants in Ghana
No full textMedicinal plants and plant-based medicines are widely used in traditional cultures all over Ghana and they are becoming increasingly popular in modern society as natural alternatives to synthetic chemicals. This paper studied the ethnobotany of medicinal plants through a socio-economic survey. Seed germination experiments were also carried out on selected medicinal plant species. It was found that the herbal medicine industry was a major source of income for 82% of the respondents. Almost 50% of the respondents were women with majority of them involved in marketing of the medicinal plant products. Out of 160 plant species marketed, 129 were collected in Ghana with Kumasi and Accra being the major marketing centres. Most of the species have multiple curative properties with over 46 diseases purported to be cured by herbal medicine. Over 100 species were reported to be in high demand, scarce or unavailable. Among the reported constraints to availability of medicinal plants were lack of cultivation, unsustainable harvesting, deforestation, wildfire and urbanization. Studies on seed germination showed that seven species out of the
ten selected for conservation had good germination, ranging from 40-74% with an average of 63.3%. This suggests the possibility of cultivating medicinal plant species on commercial scale. Based on the results, it is suggested that linkages between all stakeholders should be strengthened in order to promote conservation and commercial production of medicinal plants. Furthermore, improving the knowledge-base of scientists, traditional herbal medical practitioners, policy makers and the public on the relevance and safety of traditional plant medicine could lead to the sustainability of the medicinal plants industry in Ghana
Replication data for: Productivity of Acacia angustissima accessions at two sites in the subtropics
No full textLow leaf biomass yields coupled with small land sizes are some of the major constraints faced by smallholder farmers that grow protein-rich fodder trees and shrubs. Given these challenges, availability of highly productive seed sources would be important to enable farmers to produce leaf fodder in sufficient quantities. 14 accessions of Acacia angustissima were evaluated for leaf, wood and total biomass production at two subtropical sites with uni-modal rainfall in Zimbabwe, with the objective of identifying high leaf biomass yielding accessions. There were up to fourfold difference in biomass yield between the accessions. Leaf dry matter yield ranged from 1.65 to 8.81 Mg ha-1 and 3.7 to 12.4 Mg ha-1for
wood biomass at the higher altitude site (1530 m a.s.l.) but were much lower at 1272 m a.s.l. where they ranged between 0.37 and 4.88 Mg ha-1 for leaf and 0.4 and 7.2 Mg ha-1 for wood. The most productive accessions for leaf biomass were 16231 and 18579 at the higher altitude site, while 18586 and 18501 had the highest yields at the lower altitude. Although no one accession was consistently high yielding across the two sites, the least productive accessions were consistently poor at both sites. The advantage of using selected superior accessions over the unselect bulk seed was up to 85%. These findings underscore the need to promote the use of only high yielding accessions rather than unselect bulk seed. This study identified new, more productive accessions of A. angustissima that potentially widens the genetic base of the germplasm assembled in Zimbabwe
Fostering collective action at landscape level: Success factors of smallholder innovation platforms in the Eastern Highlands of Kenya and Uganda
No full textStrong and vibrant smallholder groups provide opportunities to the community to play a role in rural development and benefit from it. However, most of those groups do not have the capacity to individually influence rural development. Bringing groups together facilitates access to combined knowledge and leverages complementary assets. This study identifies factors influencing the success of two smallholder innovation platforms in Embu and Kapchorwa. A five-level likert scale survey questionnaire was administered to 68 groups from the two platforms that had experienced significant development in their group's capacity as a result of these platforms. Principal component analysis was used to extract indicators defining dimensions used to measure the success of these platforms. Multiple regression analysis was used to fit the model of successful linkages. The results indicate that ownership, motivation and leaders commitment skills and motives play critical roles in the success and sustainability of smallholder innovation platform
Spatial effect of dominant tree species on crop productivity, water and nutrient availability within smallholder farms in Rift Valley, Kenya
No full textTo improve sustainability of agroforestry practices while improving agroecosystem functions and soil health, a better understanding of how to optimize tree-crop interaction is required through study on the impact of tree species and spatial arrangements that minimize competition, favors complementarities and facilitative interactions among trees and associated crops. The purpose of this study was specifically to: a) determine the spatial effect of dominant tree species on soil organic C and nutrient availability within smallholder farms; b) to evaluate the effect of dominant tree species on water availability within smallholder farms; and c) to evaluate the spatial effect of dominant sp
ecies on crop productivity
Replication Data for: Determining bioclimatic space of Himalayan alder for agroforestry systems in Nepal
No full textHimalayan alder species are proven to be very useful in traditional as well as contemporary agroforestry practice. These nitrogen-fixing trees are also useful in the land restoration. Therefore, understanding the distribution of Himalayan alder and the potential zone for plantation is meaningful in the agroforestry sector. Suitable climatic zones of Alnus spp. were modelled in MaxEnt software using a subset of least correlated bioclimatic variables for current conditions (1950e2000), topographic variables (DEM derived) and Landuse Landcover (LULC) data. We generated several models and selected the best model against random models using ANOVA and t-test. The environmental variables that best explained the current distribution of the species were identified and used to project into the future. For future projections, ensemble scenarios of climate change projection derived from the results of 19 Earth System Models (ESM) were used. Our model revealed that the most favorable conditions for Alnus nepalensis are in central Nepal in the moist north-west facing slope, whereas for Alnus nitida they are in western Nepal. The major climatic factor that contributes to Alnus species distribution in Nepal appears to be precipitation during the warmest quarter for A. nepalensis and precipitation during the driest quarter for A. nitida. Future projections revealed changes in the probability distribution of these species, as well as where they need conservation and where they can be planted. Also, our model predicts that the distribution of Alnus spp. in hilly regions will remain unchanged, and therefore may represent sites that can be used to revitalize traditional agroforestry systems and extract source material for land restoration
Replication data for: Intercropping Teak (Tectona grandis) and Maize (Zea mays): Bioeconomic Trade-off Analysis of Agroforestry Management Practices in Gunungkidul, West Java
No full textProducing high quality wood meeting export standards requires intensive tree management. Using a tree-crop interactions model (WaNuLCAS) we analyzed tree management practices in intercropped teak and maize compared to teak and maize monocultures. Tradeoff analysis in intercropped teak and maize was designed in a three-treatment factorial: initial teak density (1600 trees ha-1 (2.5m × 2.5m), 1111 trees ha-1 (3m × 3m) and 625 trees ha-1 (4m × 4m)), thinning intensity (light (25%), moderate (50%) and heavy (75%) of tree density), and pruning intensity (40% and 60% of crown biomass). Cumulative maize yield in the first 5 years of teak growth increased 10% – 38% when tree density was reduced. All simulated intercropping practices produced a higher wood volume then a monoculture, as trees benefit from crop fertilization. Maximum wood volume (m ha-1) was obtained at initial tree density of 625 trees ha-1, 25% of which was thinned in year 5 and another 25% in year 15 with 40% of the crown pruned in years 4, 10 and 15. However, greater stem diameter as can be obtained with further thinning is rewarded with higher market price per volume of wood. Profitability analysis taking into account the cost of labour (for maize production, thinning and pruning) and its effect on additional timber revenue showed that the highest Net Present Value and return to labour was provided by the system with 50% thinning in year 5. Economic optimization was not sensitive to variations around the default price assumptions
Mid-Infrared Spectra (MIRS) from ICRAF Soil and Plant Spectroscopy Laboratory: Africa Soil Information Service (AfSIS) Phase I 2009-2013
No full textAfSIS Phase I was a collaborative projective funded by the Bill and Melinda Gates Foundation (BMGF), which aimed to provide a consistent baseline of soil information for monitoring soil ecosystem services in sub-Saharan Africa (SSA). Partners included, CIAT-TSBF, ISRIC, CIESIN, The Earth Institute at Columbia University and World Agroforestry (ICRAF). The Land Degradation Surveillance Framework (LDSF), developed at ICRAF, was employed to systematically sample key biopshyical indicators of land and soil health, across landscapes. LDSF sites were randomized using spatial stratification based on Koeppen-Geiger Climate zones across 19 countries in SSA. Soil samples were collected using the LDSF at two depths, 0-20 cm and 20-50 cm. Mid-infrared diffuse refectance spectroscopy (MIR) was a key soil characterization and screening tool in AfSIS. MIR measurements of the ~18,500 samples were centralized at ICRAF’s Soil-Plant Spectral Diagnostics Laboratory based in Nairobi Kenya using the Bruker Tensor 27/HTs -XT_FT-IR. The MIR dataset is provided here, organized by country