Bridging the Gap between Farmers and Researchers through Collaborative Experimentation. Cost and Labour Reduction in Soybean Production in South-Nyanza, Kenya

The Tropical Soil Biology and Fertility Institute of the International Centre of Tropical Agriculture (TSBF-CIAT) introduced dual purpose soybean varieties in south-west Kenya both to improve soil fertility by nitrogen fixation and to provide a source of better food and income. Since the start of the project in 2005, the Uriri Farmer Cooperative Society was successful in spreading the seeds over the district. Nevertheless, farmers still had problems with soybean agronomy. We therefore started a Collaborative Experiment (CE) Approach in March 2006 to make soybean production more accessible to farmers. The approach consisted of four stages: 1) information sessions; 2) participatory rural appraisal; 3) collaboration in the whole process of experimentation, from problem identification, to the design and analysis; 4) handing over to farmers. In this case study, farmers identified two main constraints to the recommended soybean production methods: 1) high labour requirement 2) lack of income to purchase the inputs. The results and discussions with farmers during the field days allowed demonstrating that the CE approach had been successful on two main aspects. First, CE was successful in defining problems and yield enhancing treatments which are accessible to deprived people. During field days, all farmers felt there was at least one of the treatments accessible to them. The second main success of the CE process was the increased awareness and interest about soybean. After less than a year of collaboration, farmers saw that soybean can bring a better life, cash for school fees and better health. The number of farmers registered in the soybean cooperative also increased from a few hundreds to 4500 that year. Several farmers started their own experiments to further adapt the recommendations to their own needs. The CE approach was thus successful in bridging the power-relations and knowledge gap between researchers and farmers and in designing appropriate technologies.Collaborative research, soybean, participation, Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,

Towards the modeling of mucus draining from human lung: role of airways deformation on air-mucus interaction

Chest physiotherapy is an empirical technique used to help secretions to get out of the lung whenever stagnation occurs. Although commonly used, little is known about the inner mechanisms of chest physiotherapy and controversies about its use are coming out regularly. Thus, a scientific validation of chest physiotherapy is needed to evaluate its effects on secretions. We setup a quasi-static numerical model of chest physiotherapy based on thorax and lung physiology and on their respective biophysics. We modeled the lung with an idealized deformable symmetric bifurcating tree. Bronchi and their inner fluids mechanics are assumed axisymmetric. Static data from the literature is used to build a model for the lung's mechanics. Secretions motion is the consequence of the shear constraints apply by the air flow. The input of the model is the pressure on the chest wall at each time, and the output is the bronchi geometry and air and secretions properties. In the limit of our model, we mimicked manual and mechanical chest physiotherapy techniques. We show that for secretions to move, air flow has to be high enough to overcome secretion resistance to motion. Moreover, the higher the pressure or the quicker it is applied, the higher is the air flow and thus the mobilization of secretions. However, pressures too high are efficient up to a point where airways compressions prevents air flow to increases any further. Generally, the first effects of manipulations is a decrease of the airway tree hydrodynamic resistance, thus improving ventilation even if secretions do not get out of the lungs. Also, some secretions might be pushed deeper into the lungs; this effect is stronger for high pressures and for mechanical chest physiotherapy. Finally, we propose and tested two adimensional numbers that depend on lung properties and that allow to measure the efficiency and comfort of a manipulation

Land reclamation using reservoir sediments in Tigray, northern Ethiopia

Accelerated soil erosion leads to sedimentation in reservoirs and a decline in their life span. As many reservoirs in northern Ethiopia are dry at the end of the dry season, we were able to evaluate the potential of using reservoir sediments for land reclamation. Stripped land from which construction material for the reservoirs had been excavated was covered with 0, 15 and 30 cm of sediment and planted with a local garlic cultivar (Allium sativum). The applied reservoir sediments had low to medium organic C and total N contents and were high in available P and exchangeable cations. The yield of garlic increased with additional available water and the application of sediments. The results show that total biomass and bulb yield were three times higher on the reclaimed plots than on the control ones (11.7 t/ha vs. 3.6 t/ha for the biomass; 7.7 t/ha vs. 2.0 t/ha for the yield). When sediment transport and labour costs were taken into account, plots with 15 cm of sediments had in the first cropping season a cost-benefit ratio of 3, whilst those with 30 cm had a cost-benefit ratio of 0.9. This study demonstrates that the use of relatively small quantities of reservoir sediments is an economically viable strategy for land reclamation. The result can be improvement in income for resource-poor farmers by as much as 76%, and the life expectancy of the reservoirs is also increased

Experimental evidence for optimal hedgerow cutting regimes for brown hairstreak butterflies

1. The Brown hairstreak butterfly has declined in range and abundance over the past 50 years, leading to designated conservation status in several European countries including England and Wales. The Brown hairstreak's decline has been linked to changes in hedgerow management, based on mortality of eggs over winter and female oviposition preferences. 2. We assessed Brown hairstreak egg abundance in late winter over 4 years in response to hedgerow management treatments to manipulate the frequency, timing, and the intensity of trimming (reduced intensity resulting in an annual increase of approximately 10 cm in hedge height and width), using a field experiment with a randomised block design. 3. Hedgerow plots cut every year to a standard height and width had the lowest Brown hairstreak egg abundance; this is the most common hedgerow management outside agri-environment schemes (AES). Cutting hedgerow plots at a reduced intensity nearly doubled the number of surviving eggs in late winter. Plots cut at a reduced frequency in autumn (once every 3 years), which forms part of current English AES, had 1.3 times more eggs than those cut annually. 4. Current AES management prescriptions are likely to benefit the Brown hairstreak, but its requirements need to be balanced with those of other taxa in relation to the timing of hedgerow cutting. Cutting hedges at a reduced intensity has previously been shown to benefit the wider Lepidoptera community as well as Brown hairstreak butterflies. Reduced intensity cutting does not currently form part of AES hedgerow prescriptions, but could be considered for inclusion in future schemes

Profitability of diammonium phosphate use in bush and climbing bean-maize rotations in smallholder farms of Central Burundi

Article purchasedSoil fertility decline is a major constraint to bean (Phaseolus vulgaris L.) and maize (Zea mays) production in the Central Highlands of Burundi. Nutrient sources, specifically fertilizers, are paramount to increasing the production in the regions. Hence, improving fertilizer use efficiency is considered as a key factor towards sustainable intensification. The use of grain legumes with low harvest indices, such as climbing beans, are assumed to improve soil fertility and fertilizer use efficiency. This study compares the rotational effects of bush and climbing bean varieties on maize and evaluates the profitability of diammonium phosphate (DAP, 18–46-0) fertilizer in the bean-maize rotations in 59 smallholder farms of Mutaho district, Gitega Province in Central Burundi. The application of DAP fertilizer significantly increased the grain yields by 14% and 21% for bush and climbing beans, respectively (P 2 $$−1) in a climbing bean-maize rotation while 45% of the farmers in a bush bean-maize rotation. Regression tree analysis showed that targeting fertilizer use to soils with higher C and clay content, and ensuring timely planting are the predominant factors to ensure fertilizer response and profitable returns. This study confirms the need for integrated soil fertility management (ISFM), and that a combination of judicious fertilizer use, an improved grain legume (climbing bean) and adjustment to local conditions (targeting to responsive soils) maximizes economic returns of legume-cereal rotation systems

Soil fertility gradients and production constraints for coffee and banana on volcanic mountain slopes in the east African rift: a case study of Mt. Elgon

Volcanic mountains in the East African Rift (e.g. Mt. Kenya, Mt. Kilimanjaro, Mt. Elgon) are some of the most productive agricultural regions, often dominated by coffee and banana cultivation. Consequently, these regions suffer from a high and increasing population density with a declining soil fertility status imposing pressure on the available land, which in turn results in encroaching into the national forests. This study documents the soil fertility constraints along the slopes of Mt. Elgon and explores its corresponding gradients in plant nutritional status. This research links the topography of Mt. Elgon to the prevailing soil types and their current fertility status. It reveals important relations and gradients between soil fertility parameters and its corresponding environment along the slope. Soil pH, soil available P and exchangeable K, Ca and Mg are significantly decreasing with elevation. Thereby, gradients and constraints in macro- and micro-nutrient uptake by coffee and banana are revealed along the toposequence and different altitude-specific nutrient limitations are determined for both crops. K, Mn and Si uptake in both crops is decreasing with elevation along the slope, while the Mo and Ni uptake in both crops is increasing. With increasing elevation, B uptake is only decreasing in coffee and P uptake is only decreasing in banana. In addition, the antagonistic interaction between K and Mg limits the Mg uptake of both crops in the lower areas, while in the high region the Mg uptake is simply limited by low soil availability. It follows that a general fertilizer recommendation cannot be made in these regions and that the soil fertility problems along these slopes should be specifically addressed and appropriately managed according to the local requirements

Beta diversity patterns reveal positive effects of farmland abandonment on moth communities

Farmland abandonment and the accompanying natural succession are largely perceived as unwanted amongst many European conservationists due to alleged negative effects on biodiversity levels. Here, we test this assumption by analysing alpha, beta and gamma diversity patterns of macro-moth communities in habitats on an ecological succession gradient, from extensively managed meadows to scrub-encroached and wooded sites. Macro-moths were light-trapped at 84 fixed circular sampling sites arranged in a semi-nested design within the National Park of Peneda-Gerês, NW-Portugal. In total, we sampled 22825 individuals belonging to 378 species. Alpha, beta and gamma diversity patterns suggest that farmland abandonment is likely to positively affect both overall macro-moth diversity and forest macro-moth diversity, and to negatively affect species diversity of non-forest macro-moth species. Our results also show that spatial habitat heterogeneity is important to maintain gamma diversity of macromoths, especially for rare non-forest species and habitat specialistsinfo:eu-repo/semantics/publishedVersio

Maize stover transfers from maize fields to banana-based agroforestry homegardens and the corresponding nutrient flows in central-northern Tanzania

Open Access ArticleMaize (Zea mays) stover produced in the drier lowland areas on the volcanic foot slopes of Mount Kilimanjaro serves as an important additional fodder for smallholder zero-grazed dairy cattle farming in the humid highland areas of the region. The obtained cattle manure is used to replenish nutrients and manage soil fertility in banana-based agroforestry homegardens of the highlands, which contributes significantly to sustaining crop production, thus food security and the livelihoods of the community. The study aims to provide a preliminary evaluation of the amounts of stover removed from smallholder maize-based fields in the lowlands and the subsequent nutrient flows to the banana-based agroforestry homegardens of the highlands. In 54 smallholder maize fields selected at random from 11 villages in the Hai and Siha districts of the Kilimanjaro region, we conducted an agronomic survey to record the types and amounts of fertilizer used, plant spacing at harvest, and maize stover biomass yield. Most of the surveyed maize-based fields received inadequate nutrient inputs, which were limited to mineral nitrogen alone if any. Of the surveyed fields, 16.7% received recommended amounts of 74 kg N ha1 by the Ministry of Agriculture, 46.3% suboptimal amounts and 37.0% did not receive fertilizer at all. Plant density was only 50% of the recommended population density. While this was only a preliminary study on nutrient flows between maize and banana-based agroecosystems, our findings demonstrated that potassium exports via harvested banana bunches exceeded the inputs in the home gardens. We conclude that (i) soil fertility management techniques, preferably integrated soil fertility management, suitable for small-scale maize production in the lowlands should be formulated while optimizing plant density to increase production, (ii) maize-based agroforestry farming system adapted to drier conditions to deal with windstorm and soil erosion problems in the lowlands is urgently needed, and (iii) wider and more detailed research on nutrient flows between maize and banana-based agroecosystems should be conducted to document their respective soil nutrient balances and the sustainability of such practice