Body composition assessment among adults in Thika, Kiambu county, Kenya

Background: Research has shown that body composition is directly related to health. Altered body composition, can greatly increase the risks of conditions such as cardiovascular disease and diabetes. Bioelectrical Impedance Analysis fosters early detection of an improper balance in the body composition, which allows for earlier intervention and prevention.Methods: This was a cross sectional analysis of body composition for adults who volunteered to be screened during a Nutrition week in Kiambu County, Kenya. A total of 301 adults were included in the assessment. Body Mass Index (BMI) and Body composition (body fat %, bone mass, muscle mass, visceral fat and water %) were measured using bioelectrical impedance analysis.Results: The age of the participants ranged from 18-99 years (mean 42.19±16.57 years). Most of the participants were males (53.5%). More than half (53.2%) of the participants had a poor BMI, 37.2% had high total body fat percentage, 12.6% had excess levels of visceral fat and 26.6% had poor water hydration status. Age (OR=0.095; p value <0.001; CI 0.033-0272) and visceral fat (r=0.74; p value <0.001) were significantly associated with the BMI. Females had a significantly higher BMI (P <0.001). Visceral fat was also positively correlated with age: r=0.74; P value <0.001.Conclusions: Sex, age and BMI were important determinants of body composition. Increased physical activity, appropriate dietary practices are crucial in maintaining a healthy BMI and body composition. For timely intervention regular nutrition screening should be promoted among different populations

Greenhouse Gas fluxes from Selected Soil Fertility Management Practices in Humic Nitisols of Upper Eastern Kenya

We quantified soil Carbon dioxide (CO2), Methane (CH4), and Nitrous oxide (N2O) fluxes five soil fertility management practices (Inorganic fertilizer (Mf), maize residue + Inorganic fertilizer (RMf), Maize residue + Inorganic fertilizer + goat manure (RMfM), maize residue + Tithonia diversifolia + goat manure (RTiM), and a Control (CtC)) in Kenya's central highlands using a static chamber method from March 2019 to March 2020. The cumulative annual soil CH4 uptake ranged from -1.07 to -0.64 kg CH4-C ha-1 yr-1, CO2 emissions from 4.59 to 9.01 Mg CO2-C ha-1 yr-1, and N2O fluxes from 104 to 279 g N2O-N ha-1 yr-1. The RTiM produced the highest CO2 emissions (9.01 Mg CO2-C ha-1 yr-1), carbon sequestration (3.99 Mg CO2- eq ha-1), yield scaled N2O emissions (YSE) (0.043 g N2O-N kg-1 grain yield), the lowest net global warming potential (net GWP) (-14.7 Mg CO2-eq ha-1) and greenhouse gas intensities (GHGI) (-2.81 Kg CO2-eq kg-1 grain yield). We observed average maize grain yields of 7.98 Mg ha-1 yr-1 under RMfM treatment. Integrating inorganic fertilizer and maize residue retention resulted in low emissions, increased soil organic carbon sequestration and high maize yields

Soil Organic Carbon and Acid Phosphatase Enzyme Activity Response to Phosphate Rock and Organic Inputs in Acidic Soils of Central Highlands of Kenya in Maize

Aims: To evaluate the effects of phosphate rock and organic inputs on soil organic carbon and acid phosphatase activity. Study Design: The experiment was laid in Randomized Complete Block Design with seven treatments replicated thrice. Place and Duration of Study: The study was conducted at Kigogo Primary school in Meru South Sub-county, Tharaka Nithi County, Kenya. The experiment ran for two consecutive seasons the short rains of 2017 (October to December) and long rains of 2018 (March through June). Methodology: There were seven treatments replicated thrice. The treatments included Tithonia diversifolia, Phosphate rock (PR), Goat manure, Tithonia diversifolia + Phosphate rock, Goat manure + Phosphate rock, Triple superphosphate + Calcium ammonium nitrate and a Control (no soil external inputs). The test crop was maize (Zea mays L.) H516 variety. Soil organic carbon followed modified Walkley and Black oxidation method while acid phosphatase enzyme activity was essayed following the method by Tabatabai and Bremner. Results: Goat manure + phosphate rock, sole phosphate rock and use of goat manure significantly (P= .0001) increased soil organic carbon by 198, 100 and 71% compared to the control. Tithonia diversifolia reported a 3.4-fold increase in soil organic carbon compared to the control in short rains of 2017. Goat manure gave higher soil organic carbon by 135% compared to the control in the long rains of 2018. Goat manure + phosphate rock treatment significantly (P= .0002) increased the phosphatase activity by a difference of 1.12% compared with the control, with 2.14% decreases under TSP+CAN treatment compared to the control. Conclusion: The results showed that integration of phosphate rock and manure could have a far-reaching influence on soil organic carbon and acid phosphatase activity thus could be recommended for improved soil productivity in humic nitisols in similar agro-ecological zones

The effect of minimum tillage and animal manure on maize yields and soil organic carbon in sub ‐Saharan Africa: A meta-analysis

In sub-Saharan Africa (SSA), diminishing soil fertility has been experienced from continuous cropping and low nutrient replacement. Organic inputs and minimum tillage are proposed to increase the declining fertility of the soil to increase crop growth and yields. We reviewed animal manure and minimum tillage use on maize yields and soil organic carbon (SOC) in SSA. This involved a meta-analysis on the influence of minimum tillage and animal manure on maize grain yields and SOC. The peer-reviewed publications on animal manure and minimum tillage influence on maize yields and SOC were selected from articles that contained one or multiples of the following keywords, 'tillage, minimum tillage, conventional tillage, organic, manure, animal manure' using ScienceDirect database. Reported data on maize yields and soil organic carbon were extracted from figures, tables, and text, of the selected studies. These studies were analyzed using R, and results were presented in a forest plot. Minimum tillage had no significant influence on maize yields and soil organic carbon. Animal manure significantly improved maize yields and soil organic carbon. The study underscored the importance of animal manure in improving maize yields and soil organic carbon in SSA. Animal manure application in maize cropping systems is plausible to increase maize yields and soil organic carbon in SSA

Fire and Herbivory Interactively Suppress the Survival and Growth of Trees in an African Semiarid Savanna

There has been a long-standing interest in understanding how interactions between fire and herbivory influence woody vegetation dynamics in savanna ecosystems. However, controlled, replicated experiments examining how different fire regimes interact with different herbivore groups are rare. We tested the effects of single and repeated burns, crossed with six replicated herbivore treatments, on the mortality and growth of woody vegetation in the Kenya Long-term Exclosure Experiment plots located in a semi-arid savanna system in central Kenya. Burned plots experienced higher tree mortality overall, but differences between burns and non-burns were only significant in plots excluding all wild herbivores and in plots accessible to megaherbivores. Cattle ameliorated the negative effects of repeat burns on tree mortality, perhaps by suppressing fuel load accumulation. Across all herbivore treatments, trees experienced a significant reduction in height within the first two years after fire (top-kill), which was followed by a gradual recovery. Saplings and coppices subjected to repeated burns regrew faster than those that were burned once, except in the presence of megaherbivores. This study highlights strong context-dependent interactions between fire and different herbivore groups, and extends previous approaches to understanding fire&ndash;herbivory interactions, which have tended to lump the effects of different herbivore groups, or study them separately

Determinants of farmers’ knowledge on soil and water conservation technologies in dry zones of Central Highlands, Kenya

This study ascertained the socioeconomic determinants of farmers’ knowledge on soil and water conservation technologies in Dry zones of Central Highlands of Kenya involving 400 farming households. Results showed that the majority of the farmers had inadequate knowledge on the use and benefits of soil and water conservation technologies. The socio-economic factors that influence knowledge levels of the knowledge-intensive technologies were education level, gender, perceptions on soil fertility, farmer group membership, access to training, farm size, access to credit, number of livestock kept and access to farm equipment. This implies that there is the need to come up with an all-inclusive policy that can be employed in improving farmer’s level of knowledge through the use of more innovative methods of information dissemination. This can be done by strengthening the existing farmer groups, enhancing extension services, and also formulating gender-friendly policies