Uptake of selected antiretrovirals by pepper (Capsicum annum), radish (Raphanus sativus), and ryegrass (Lolium perenne) grown on two contrasting soils and fertilized with human urine-derived fertilizers.

The use of urine-derived fertilizers has several economic and environmental advantages. However, there is concern that pharmaceutical residues present in urine could enter the food chain after plant uptake and pose potential risks to human and animal health. A pot experiment was conducted to evaluate the uptake of nine target antiretroviral drugs (ARVDs) by pepper (Capsicum annum), ryegrass (Lolium perenne) and radish (Raphanus sativus) grown in two soils of contrasting texture and organic matter content and fertilized with stored urine, nitrified urine concentrate (NUC), and struvite.

Total organic carbon, aluminium and iron in bulk samples and aggregate size fractions of a sandy clay loam humic soil under sugarcane relative to native forest in northern KwaZulu-Natal, South Africa.

The distribution of total aluminium (Al) and iron (Fe) and organic carbon (TOC) in aggregate fractions gives an insight into the dynamics of these elements in soil. This study determined the effects of over 30 years of sugarcane cultivation, compared to adjacent native forest, on Al, Fe and TOC in bulk soil and aggregate fractions within the 100 cm depth of a sandy clay loam humic soil. Samples were separated into large macro-aggregates: LM (>2000 μm), small macro-aggregates: SM (250-2000 μm), micro-aggregates: M (250-63 μm) and silt + clay: SC (<63 μm) fractions.

Land use and site effects on the distribution of carbon in some humic soil profiles of KwaZulu-Natal, South Africa.

Land use effects on the stocks of soil organic carbon (SOC) are generally based on the topsoil. Although subsoil horizons have lower concentrations, they contain a significant amount of SOC which may be more strongly protected than that in the topsoil layers. Analysis of SOC storage must therefore include the whole profile in respect of climate change mitigation.