134 research outputs found
The IITA agripreneur movement: a dynamic approach to youth empowerment across Africa
The Agripreneur Movement of the International Institute of Tropical Agriculture (IITA) allows youth to assume their rightful place in African agricultural transformation. It started as a single exploratory agribusiness incubation at IITA Headquarters in 2012, involving 37 youths. It has since grown to 10 countries through nine sponsoring organizations. We compiled the characteristics and outcomes of 40 Agripreneur projects between 2012 and 2021 to describe the movementâs growth. With time, the movement operated across 195 locations engaging 518 trainers within 493 training cohorts and 263 different learning enterprises. These efforts led to the training of 25,616 youth in modern agriculture and agribusiness, resulting in 1,661 modernized farms and 2,592 business start-ups. Of the learning enterprises, 38% involved crops, 32% involved agro-processing, and 30% involved animal husbandry, suggesting a sound balance in promoting agribusiness opportunities. About $38.5 million was directed toward the training and support of Agripreneurs between 2012 and 2021. We trace the origins of the Agripreneur Movement as isolated agribusiness incubations in Nigeria through its expansion to other countries and its adoption within the youth empowerment agendas of other development organizations, including the African Development Bank, the International Fund for Agricultural Development, and the Mastercard Foundation. In this way, the legion of youth working with and inspired by the IITA Agripreneur Movement makes major contributions to and secures their rightful place within a complex array of rural development opportunities. What must occur next is its mainstreaming across the vocational agriculture systems and developmental sovereign loans of African countries
Experimental Demonstration of an Electride as a 2D Material
Because of their loosely bound electrons, electrides offer physical
properties useful in chemical synthesis and electronics. For these applications
and others, nano-sized electrides offer advantages, but to-date no electride
has been synthesized as a nanomaterial. We demonstrate experimentally that
CaN, a layered electride in which layers of atoms are separated by layers
of a 2D electron gas (2DEG), can be exfoliated into two-dimensional (2D)
nanosheets using liquid exfoliation. The 2D flakes are stable in a nitrogen
atmosphere or in select organic solvents for at least one month. Electron
microscopy and elemental analysis reveal that the 2D flakes retain the crystal
structure and stoichiometry of the parent 3D CaN. In addition, the 2D
flakes exhibit metallic character and an optical response that agrees with DFT
calculations. Together these findings suggest that the 2DEG is preserved in the
2D material. With this work, we bring electrides into the nano-regime and
experimentally demonstrate a 2D electride, CaN
Long-term Impact of sewage sludge application on rhizobium leguminosarum biovar trifolii: an evaluation using meta-analysis
The Long-Term Sludge Experiment (LTSE) began in 1994 at nine UK field sites as part of continuing research into the effects of sludge-borne heavy metals on soil fertility. The long-term effects of Zn, Cu, and Cd on the most probable numbers of cells (MPN) of Rhizobium leguminosarum biovar trifolii were monitored for 8 yr in sludge-amended soils. To assess the statutory limits set by the UK Sludge (Use in Agriculture) Regulations, the experimental data were reviewed using statistical methods of meta-analysis. Previous LTSE studies have focused predominantly on statistical significance rather than effect size, whereas meta-analysis focuses on the magnitude and direction of an effect, i.e., the practical significance rather than its statistical significance. Results showed Zn to be the most toxic element causing an overall significant decrease in Rhizobium MPN of â26.6% during the LTSE. The effect of Cu showed no significant effect on Rhizobium MPN at concentrations below the UK limits, although a â5% decrease in Rhizobium MPN was observed in soils where total Cu ranged from 100 to <135 mg kgâ1. Overall, there was nothing to indicate that Cd had a significant effect on Rhizobium MPN below the current UK statutory limit. In summary, the UK statutory limit for Zn appears to be insufficient for protecting Rhizobium from Zn toxicity effects
Effects of hatchery broodstock collection on adult Muskellunge populations
Muskellunge Esox masquinongy stocking programs throughout North America rely on the collection of wild adult Muskellunge to acquire gametes for hatchery propagation. The process of collecting, transporting, confining, handling, and spawning broodstock Muskellunge may cause mortality that could alter Muskellunge density, size structure, and population survival rates. We used longâterm Muskellunge captureârecapture data collected from the Iowa Great Lakes and Clear Lake in northern Iowa, USA to estimate the number and proportion of Muskellunge captured annually and initial mortality rates resulting from broodstock collection. We also evaluated whether Muskellunge apparent survival rates differed between individuals used as broodstock and those that were not captured annually. Finally, we evaluated whether the number of initial mortalities or the number of individuals captured were related to annual population survival estimates. Collectively, 7,010 adult Muskellunge (3,896 males and 3,114 females) captures occurred between 2001â2017 and population densities within a system ranged from 0.11 to 0.39 fish/ha. An average of 33% (range: 13% â76%) of the population was captured during broodstock operations annually. Between 0 and 28 (0.0000 to 0.0191 fish/ha) Muskellunge died at each hatchery annually and more males died than females (total of 150 males and 68 females; 3.9% and 2.2% of captured fish, respectively). However, annual mortalities were generally a low proportion of Muskellunge in the lake (\u3c2%; \u3c0.001 fish/ha). There was some evidence of size selective mortality, particularly for males, where larger individuals (875â975 mm) were more likely to die, but we found no evidence to suggest that broodstock collection affected annual population survival estimates. Muskellunge broodstock mortality appears to act in a compensatory manner with natural mortality, and other sources of population mortality are more likely to have a greater effect on the population
Mapping the drivers of parasitic weed abundance at a national scale : a new approach applied to Striga asiatica in the midâwest of Madagascar
The parasitic weed genus Striga causes huge losses to crop production in subâSaharan Africa, estimated to be in excess of $7 billion per year. There is a paucity of reliable distribution data for Striga ; however, such data are urgently needed to understand current drivers, better target control efforts, as well as to predict future risks. To address this, we developed a methodology to enable rapid, largeâscale monitoring of Striga populations. We used this approach to uncover the factors that currently drive the abundance and distribution of Striga asiatica in Madagascar. Two longâdistance transects were established across the middleâwest region of Madagascar in which S. asiatica abundance in fields adjacent to the road was estimated. Management, crop structure and soil data were also collected. Analysis of the data suggests that crop variety, companion crop and previous crop were correlated with Striga density. A positive relationship between withinâfield Striga density and the density of the nearest neighbouring fields indicates that spatial configuration and connectivity of suitable habitats is also important in determining Striga spread. Our results demonstrate that we are able to capture distribution and management data for Striga density at a landscape scale and use this to understand the ecological and agronomic drivers of abundance. The importance of crop varieties and cropping patterns is significant, as these are key socioâeconomic elements of Malagasy cropping practices. Therefore, they have the potential to be promoted as readily available control options, rather than novel technologies requiring introduction
Carbon losses and sequestration with land use change in the humid tropics.
Changes in carbon stocks associated with the different land use systems combined with details on the time course of these changes during the land use rotation are necessary to estimate the net carbon losses and sequestration potential associated with these different land use conversions
Potential of East African phosphate rock deposits in integrated nutrient management strategies
CaracterĂsticas simbiĂłticas e fenotĂpicas de Azorhizobium doebereinerae, microissimbiote de Sesbania virgata
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