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Biochar application to a structurally poor tropical soil could potentially alter the soil's aggregate strength and hydraulic properties. However, very few field studies have investigated the impact of biochar on the aggregate strength and hydraulic properties of tropical soils. A field experiment was therefore conducted to investigate the short-term effects of rice straw biochar on soil hydraulic properties and aggregate stability of an Acrisol in Ghana. The biochar was broadcast at rates of 10 t [ha.sup.-1] and 20 t [ha.sup.-1] as single applications that were incorporated into the top 20 cm of the soil using a spade and then the soil was levelled using a rake. Field saturated hydraulic conductivity and laboratory-measured soil water retention, aggregate stability and water-repellency were determined 10 months after the biochar application. Biochar increased aggregate stability against fast wetting by up to 33% compared to the control. This implies that biochar might improve the stability of aggregate of an Acrisol against slaking and erosivity of heavy rainfall. However, aggregate stability against slow wetting and mechanical breakdown after pre-wetting were unaffected by the biochar. Biochar did not affect field saturated hydraulic conductivity, water retention characteristics and water-repellency. Further field studies on weathered tropical soils with low native soil organic matter is recommended to elucidate the effect of repeated biochar addition on soil hydraulic and aggregate characteristics. Keywords: aggregate stability, biochar, carbon sequestration, hydraulic conductivity, hydrophobicity, organic amendment, pyrolysis, soil water retention, tropical soils, water repellency., Introduction Biochar, a carbon-rich by-product from pyrolysis of biomass, has gained wide research interest due to its potential to promote agricultural productivity, carbon sequestration and soil remediation by absorbing organic [...]

BACKGROUND:There is paucity of information on antibiotics utilization amongst farmers, factors associated with administration of antibiotics and farmers' knowledge of the effects of antibiotics on the soil ecosystem in Ghana. METHODS:A cross sectional quantitative survey across three coastal regions of Ghana was undertaken amongst poultry and livestock farmers. Six hundred respondents were selected from five districts each across the three regions. Pretested and structured questionnaire were used to collect data through face to face interview. Data were summarized using descriptive statistics and regression analysis. Factors associated with antibiotic administration were determined using binary multiple logistic regression at p ≤ 0.05. RESULTS:Out of the 600 farmers, 95% administered antibiotics and 84% bought antibiotics over-the-counter without prescription. Approximately 9% of antibiotic administration was carried out by veterinary officers, and the remaining, 91% based on farmer's experience. Approximately 93% had access to antibiotics without any difficulty. Withdrawal period was always observed by only 16% of farmers. Majority (74%) of farmers never had education on antibiotics and none of the farmers screened manure for the antibiotic residuals. Years of farming, income status, level of education of farmers, type of animal kept, access to extension services, registration with farmers' association, employing veterinary services, location of farm, system of production, education on antibiotics and access to antibiotics positively and significantly predicted the administration of antibiotics by farmers. Majority of farmers had inadequate knowledge of the effects of antibiotics on soil ecosystem with mean score ranging between 2.87±0.60 and 2.98 ± 0.7 on a scale of 5.0. CONCLUSION:The study exposed the poor practices regarding antibiotic use and also inadequate knowledge on its effect on the soil ecosystem amongst farmers in Ghana. This calls for development of strategies to increase awareness on antibiotics because its misuse can negatively impact human, animals, environment and impact food security.