Selenium, a ubiquitously occurring element in the environment, is classified as an essential element for human and animal health because, among others, it has antiviral and anticarcinogenic effects and plays a biological role as a component of the antioxidant enzyme glutathione peroxidase that catalyzes the decomposition of H2O2 and consequently protects cells from oxidative damage. Dietary Se intake in Malawi is <20 µg person-1 day-1, which is low compared to recommended 50-70 µg person-1 day-1 worldwide. Selenium bioavailability is affected largely by acidity effects. This study was aimed at determining liming effects on Se availability. Extractable Se significantly increased with increasing Se applications from 0.12 mg Se kg-1 to 0.32 mg Se kg-1. Extractable Se content of the soil to which no Se had been added was 0.09 mg kg-1 but increased with increasing liming effects to 0.15 mg kg-1 at 5 t lime ha-1. Selenium uptake also increased with increasing lime application. About 95% of total variation in Se contents in maize grain was accounted for by liming effects while Se application accounted for about 98% of the total variation in maize grain Se contents. Lime and selenium effects on grain Se contents were statistically significant (P 0.001).
Prof. Dr. Bilal BİLGİN