Agronomic management controls microbial populations in soils of western Kenya

The provision of food requirements for current and future generations can be guaranteed through agricultural intensification options that safeguard the production resource base. Over the years, the debate on sustainable agricultural intensification has not been matched with due regard to how the intensification options influence the functions and balance of soil organisms and soil biology in general. Soil mesofauna and microorganisms have received very little attention so far. In sub-Saharan Africa (SSA) especially, there is very little knowledge and documentation of soil micro-organismal functioning and how these affect and are affected by the abiotic environment (soil physical and chemical properties, and climatic conditions), as well as agricultural management and intensification. Therefore, there is need to evaluate how measures to restore soil fertility and improve its productivity influence not only crop productivity and soil physical and chemical changes, but also soil biology, i.e. the diversity of macro-, meso- and micro-fauna and flora. In addition, the impact of ‘sustainable’ intensification on the evolution of greenhouse gas (GHG) emissions and related climate footprint remains to be assessed in a comprehensive manner. Key intensification options currently under promotion by practitioners include conservation agriculture and various integrated soil fertility management (ISFM) options. Minimum soil disturbance, a minimum soil cover of at least 30% throughout the season and crop rotation/intercropping, all of which are principles of conservation agriculture (CA), have been shown to not only introduce shifts in microbial populations but also improve soil structure (Kihara et al., 2012) and enhance carbon sequestration in the top soil. On the other hand, increased aggregation in CA provides anaerobic microsites suitable for micro-organisms that contribute to nitrogen (N) losses through denitrification, and the release of nitrous oxide (N2O); a potent GHG. How such losses are influenced by nutrient inputs, such as through application of mineral fertilizer or biological N fixation, remains largely un-assessed in SSA. The use of chemical fertilizers, one way of increasing crop productivity in SSA, can have variable effects on microbial biomass and activity (Wardle, 1992; Treseder, 2008). For instance, increased amounts of readily available forms of key inorganic mineral nutrients, e.g. N and P, can decrease population and diversity of various microbial functional groups associated with nutrient uptake (e.g. arbuscular mycorrhizae fungi) and nitrogen fixation (e.g. rhizobium) (Azcón-Aguilar and Bago, 1994; Smith and Read, 1997). On the other hand, fertilizer use increases plant biomass production which, when returned to the soil, promotes microbial proliferation and diversity (Álvarez, 2005). The effects of fertilizer use, either alone or in combination of organic resources, on soil micro-organisms need, therefore, to be evaluated in order to guide sound soil management practices

Road traffic fatalities - a neglected epidemic in rural northern Ghana: evidence from the navrongo demographic surveillance system

Globally, road traffic fatalities have been on the increase, particularly in low-and-middle income countries. Much of this is attributed to increases in the acquisition, and use of motorized vehicles. However, there is very little empirical research to understand the causes and determinants of this threat. This paper investigates time trends and determinants of road traffic accidents in the Kasena-Nankana district of northern Ghana. First, we utilized causes of death data gathered by the Health and Demographic Surveillance System in Navrongo, to examine trends in deaths due to injury, particularly those related to road traffic crashes. Subsequently, we employed multivariate logistic regression to examine factors associated with deaths due to all injuries and road traffic crashes among adults 15–59 years of age. Results show a three-fold increase in mortality (18%) due to injuries in the Kasena-Nankana district in about a decade. Fatalities resulting from road traffic crashes constitute the greatest share of the burden of mortality resulting from injuries. Increases in road traffic fatalities have coincided with recent increases in motor and vehicular traffic in the region. Several factors are associated with the increased risk of deaths from road traffic accidents, principal among which include urban residence (OR = 1.74 95% CI 1.09-2.78), being male and in the prime adult ages of between 20–29 years old (OR = 4.85 95% CI 2.65-8.89), as well as people with higher levels of education (OR = 3.21 95% CI 1.75-5.87) and those in higher socioeconomic status categories (OR = 2.43 95% CI 1.21-4.88). Results suggest that road traffic fatalities have become a major cause of morbidity and mortality and brings into focus the need for measures to curb this looming crisis. There is need for strategic interventions to be adopted to avert what is sure to become one of the leading causes of death in this impoverished locality

Conservation Agriculture Enhances Soil Fauna Richness and Abundance in Low Input Systems: Examples From Kenya

Conservation agriculture (CA) (zero tillage + organic inputs as surface residue) is believed to improve soil nutrient status, soil structure, control soil erosion, and also enhance soil fauna diversity. Despite the widespread interest in CA, empirical evidence of the benefits of CA on soil fauna diversity is limited, especially in low-input systems of sub-Saharan Africa (SSA). Consequently, the magnitude and effect by CA on soil fauna remains unquantified. The aim of this study was to evaluate the effect of CA and associated management practices on soil fauna richness and abundance. We hypothesized that CA and mixed cropping would positively influence soil fauna richness and abundance. We compared CA with conventional till (CT; with or without residues) in sole maize and maize-bean cropping systems. Soil macrofauna and mesofauna were sampled across the treatments in medium-term (6 years) trials in Embu, Central Kenya, and Kakamega (6 years) and a long-term trial in Nyabeda (15 years) using soil monoliths and core samplers, respectively. In agreement with our hypothesis, higher macrofauna taxonomic richness and mesofauna was recorded in CA than in CT without residues. This study demonstrated that: (1) medium to long-term addition of organic residues enhances soil fauna richness and abundance, (2) CA increases soil fauna taxonomic richness and abundance compared with CT, and (3) CA under maize-bean intercropping, rotation and sole maize cropping systems promote soil fauna richness and abundance compared with sole legume (common beans). We conclude that adoption of CA is important in enhancing richness of soil fauna. Given the numerous challenges faced by smallholder farmers of SSA in the adoption of CA, who in most cases rarely practice all the three CA principles simultaneously, we propose a further study that will determine the effects and interactions between each of the CA components on soil fauna richness and abundance

TRADE-OFFS IN TREE SPECIES SELECTION AND CARBON OFFSET ON FARMS ADJACENT TO KAKAMEGA-NANDI FOREST ECOSYSTEM IN KENYA

Background: Growing of trees on-farms has contributed significantly in easing pressure on the Kakamega–Nandi Forest Ecosystem. There are however concerns that Eucalyptus species is becoming the dominant tree in this landscape and may have adverse effects on the environment. Objectives: To determine the trade-offs in tree species selection and carbon offsets on farms in the margins of the Kakamega - Nandi Forest Ecosystem. Methodology: It employed a nested experimental design where the study area was divided into three 3x1 km sentinel blocks. Three different landscape models were chosen: Eucalyptus dominated tree stand, mixed tree stands and pure native tree stands. A sample plot comprised a main plot of 20m by 10m plot for measuring trees with a diameter at breast height (DBH) ≥ 10 cm, a sub-plot of 10m by 5m nested within the main plot for measuring saplings and shrubs of DBH less than 10cm. Data was collected on tree species type, stem DBH for trees, tree height, counts of trees, saplings and shrubs. The data was subjected to both exploratory and inferential statistical analysis using R Gui Version 4.2.1. Woody species diversity and carbon stocks were subjected to analysis of variance (ANOVA) at 5% significance level. Results: Native dominated tree stands had the highest biomass carbon (0.50-512.84 MgC ha-1) followed by mixed tree stands (0.10-110.82 MgC ha-1). Eucalyptus dominated was the least (0.10- 68.58 MgC ha-1) The above ground biomass in the Eucalyptus dominated tree stands and mixed trees stands was significantly lower than in the adjacent native trees stands (p=0.001). The mean carbon estimated in the treatments was 2.62 MgC ha-1 in the Eucalyptus trees dominated stands, 3.09 MgC ha-1 in mixed trees species stands and 19.05 MgC ha-1 in native tree species stand. Implications: Increase in the concentration of Eucalyptus trees led to a reduction in tree diversity. Trees in the Eucalyptus dominated tree stand and mixed trees stand had significantly lower stem diameters, basal area and tree biomass than in the adjacent indigenous trees stand. The fast rate of growth of Eucalyptus trees may have ensured that the trees grow fast at the expense of other woody species due to water and nutrient competition. Conclusion: The study revealed a general trend of increasing biomass carbon with increasing tree size in all the treatments. The majority of large trees were found in native tree stand indicating that they store majority of biomass carbon stocks. Across the treatment, carbon sequestration in the trees was directly related to above ground biomass production

The way forward.

Good public-health decisionmaking is dependent on reliable and timely statistics on births and deaths (including the medical causes of death). All high-income countries, without exception, have national civil registration systems that record these events and generate regular, frequent, and timely vital statistics. By contrast, these statistics are not available in many low-income and lower-middle-income countries, even though it is in such settings that premature mortality is most severe and the need for robust evidence to back decisionmaking most critical. Civil registration also has a range of benefits for individuals in terms of legal status, and the protection of economic, social, and human rights. However, over the past 30 years, the global health and development community has failed to provide the needed technical and financial support to countries to develop civil registration systems. There is no single blueprint for establishing and maintaining such systems and ensuring the availability of sound vital statistics. Each country faces a different set of challenges, and strategies must be tailored accordingly. There are steps that can be taken, however, and we propose an approach that couples the application of methods to generate better vital statistics in the short term with capacity-building for comprehensive civil registration systems in the long run