Effects of Compost Manure on Soil Microbial Respiration, Plant-Available-Water, Peanut (Arachis hypogaea L.) Yield and Pre-Harvest Aflatoxin Contamination

Peanut production in Zambia is often characterized by low yields and high aflatoxin incidence in harvested kernels. Soil amendments such as farmyard manure have shown potential to increase yields and reduce pre-harvest aflatoxin incidence. The aim of the current study was to evaluate the effects of composted cattle manure on soil properties that relate to yield and pre-harvest aflatoxin contamination of peanut kernels. Research evaluated the effects of composted cattle manure on soil respiration, plant-available water (PAW), peanut yield and pre-harvest aflatoxin contamination in a field experiment conducted in two successive rain-fed cropping seasons starting in December, 2015 and ending in April 2017, in Chongwe District, Zambia. Six (6) levels of compost were incorporated into the top 10 cm of the soil at rates of 0, 4.5, 12.0, 19.5, 27.0, and 34.5 metric tons/ha 1 wk before planting. There was a strong positive relationship between levels of compost and soil microbial respiration (R2=0.84) and PAW (R2=0.86). Secondly, compost manure was associated with increases in pod (R2=0.65) and kernel (R2=0.61) yield. The kernel yield potential of the planted cultivar was achieved at the rate of 12 metric tons per ha. Thirdly, there was a reduction in total aflatoxin levels with increasing levels of compost (R2=0.85). The improvement in peanut yield and the decrease in aflatoxin concentrations in kernels can be attributed to the improvement in soil moisture retention capacity and soil microbial activity arising from manure amendments. This study demonstrated the potential of compost manure to increase soil microbial activity, PAW, peanut yield and minimize aflatoxin contamination at field level

Effects of biochar and gypsum soil amendments on groundnut (Arachis hypogaea L.) dry matter yield and selected soil properties under water stress

The effects of amending soil with gypsum and biochar on groundnut chlorophyll concentration, water use efficiency (WUE), biomass yield and selected soil properties were investigated under water stress. Gypsum (CaSO4.2H2O) was applied at 0 and 200 kg/ha, groundnut shell biochar at 1, 2 and 4% w/w of soil, and water at 100, 70 and 40% of daily plant water requirement (PWR) as main, sub and sub-sub plots, respectively, in a split-split-plot design. Biochar neutralized the acid soil, significantly raising soil pH from 5 to 7.15 and increasing cation exchange capacity by 75%. Biochar amended at 1 and 2%, increased groundnut dry matter yield by 28%. The optimum biochar application rate for dry matter yield was 1.4% w/w. Biochar application at 4% and irrigation at 40% of PWR reduced the WUE by 45 and 50%, respectively. Chlorophyll concentration index was highest at 40% of PWR. The results suggest that biochar has potential to raise soil pH, increase moisture retention and improve crop performance. Applying water at 100% PWR can increase groundnut dry matter yields, while higher gypsum application rates may be required to affect crop performance

Developing fencing policies in dryland ecosystems

The daily energy requirements of animals are determined by a combination of physical and physiological factors, but food availability may challenge the capacity to meet nutritional needs. Western gorillas (Gorilla gorilla) are an interesting model for investigating this topic because they are folivore-frugivores that adjust their diet and activities to seasonal variation in fruit availability. Observations of one habituated group of western gorillas in Bai-Hokou, Central African Republic (December 2004-December 2005) were used to examine seasonal variation in diet quality and nutritional intake. We tested if during the high fruit season the food consumed by western gorillas was higher in quality (higher in energy, sugar, fat but lower in fibre and antifeedants) than during the low fruit season. Food consumed during the high fruit season was higher in digestible energy, but not any other macronutrients. Second, we investigated whether the gorillas increased their daily intake of carbohydrates, metabolizable energy (KCal/g OM), or other nutrients during the high fruit season. Intake of dry matter, fibers, fat, protein and the majority of minerals and phenols decreased with increased frugivory and there was some indication of seasonal variation in intake of energy (KCal/g OM), tannins, protein/fiber ratio, and iron. Intake of non-structural carbohydrates and sugars was not influenced by fruit availability. Gorillas are probably able to extract large quantities of energy via fermentation since they rely on proteinaceous leaves during the low fruit season. Macronutrients and micronutrients, but not digestible energy, may be limited for them during times of low fruit availability because they are hind-gut fermenters. We discuss the advantages of seasonal frugivores having large dietary breath and flexibility, significant characteristics to consider in the conservation strategies of endangered species

Online Early

Background. Beta-adrenergic receptor blocker (BARB) drugs are a wide range of medicines that are used in various conditions, including chronic heart failure (HF). Several studies have reported a wide-ranging inappropriate use of evidence-based beta-blockers (EBBBs) in chronic HF in both inpatients and outpatients. Objectives. To assess the utilisation and optimisation of EBBBs among patients with HF who presented with a reduced ejection fraction (HFrEF). Methods. A hospital-based retrospective cross-sectional study was carried out at the Adult University Teaching Hospital (AUTH), in Lusaka, Zambia, where patient medical files for the period of 1 July 2018 to 31 July 2021 were reviewed. Patient information, including file number, age, sex, type of BARB and the dose used, was recorded on the developed and validated checklist. Multivariable regression analysis was performed to identify factors associated with utilisation of BARBs. Results. Of the 173 medical records reviewed, BARBs were utilised in 101 (58.4%) patients. Among the patients who utilised BARBs, 96 (95.0%) were taking EBBBs, while the rest (n=5, 5.0 %) were taking atenolol, which is a non-EBBB. Among the patients who were on EBBBs, none of them received the optimal dose. Age ≥65 years (adjusted odds ratio (aOR) 0.3, 95% confidence interval (CI) 0.17 - 0.64), previous hospitalisation (aOR 0.3, 95% CI 0.13 - 0.51) and furosemide dose ≥40 mg (aOR 0.4, 95% CI 0.21 - 0.64) were significantly associated with lower likelihood of BARB utilisation. New York Heart Association (NYHA) class II (aOR 3.4, 95% CI 1.08 - 10.7), NYHA class III (aOR 4.8, 95% CI 1.65 - 13.7) and patients using at least 5 medications (aOR 5.0, 95% CI 2.91 - 8.77) were independent predictors of BARB utilisation. Conclusion. This study showed that 95.0% of chronic HF patients were utilising EBBBs, and none received the optimal dose as recommended in the guidelines. Pharmacotherapy with EBBBs should be optimised among patients with chronic HfrEF, as these drugs reduce both morbidity and mortality

Transdisciplinary innovation in irrigated smallholder agriculture in Africa

Boosting the productivity of smallholder farming systems continues to be a major need in Africa. Challenges relating to how to improve irrigation are multi-factor and multisectora l, and they involve a broad range of actors who must interact to reach decisions collectively. We provide a systematic reflection on findings from the research project EAU4Food, which adopted a transdisciplinary approach to irrigation for food security research in five case studies in Ethiopia, Mali, Mozambique, South Africa and Tunisia. The EAU4Food experiences emphasize that actual innovation at irrigated smallholder farm level remains limited without sufficient improvement of the enabling environment and taking note of the wider political economy environment. Most project partners felt at the end of the project that the transdisciplinary approach has indeed enriched the research process by providing different and multiple insights from actors outside the academic field. Local capacity to facilitate transdisciplinary research and engag ement with practitio ners was developed and could support the continuation and scaling up of the approach. Future projects may benefit from a longer time frame to allow for deeper exchange of lessons learned among different stakeholders and a dedicated effort to analyse possible improvements of the enabling environment from the beginning of the research process

Conserving large populations of lions - the argument for fences has holes

Packer et al. reported that fenced lion populations attain densities closer to carrying capacity than unfenced populations. However, fenced populations are often maintained above carrying capacity, and most are small. Many more lions are conserved per dollar invested in unfenced ecosystems, which avoid the ecological and economic costs of fencing