Nutritivne vrednosti komposta, vermikomposta i dugoročni efekat na status plodnosti zemljišta

The principal aim of this study was to examine the nutrient release pattern from two types of composts and long-term implications on soil fertility status. An incubation experiment was carried out in the laboratory to determine the nutrient release patterns from compost and vermicompost mixed with soil at different application rates of SC30, SC70, SC120 and SV30, SV70 SV120 respectively for 21 days. Initial pre-incubation analysis of the compost material used for the experiment showed that both the compost and vermicompost had high nutrient content. The results further revealed that the different rates of compost and vermicompost application to soil had significant influence on the slow, gradual release process, indicating the long-term effect the organic fertilizers could exert on soil fertility statusGlavni cilj ove studije je bio ispitivanje obrazca oslobađanja hranljivih materija iz dva tipa komposta i dugoročne posledice na status plodnosti zemljišta. Izvršen je eksperiment inkubacije u laboratoriji da bi se utvrdili obrasci oslobađanja hranljivih materija iz komposta i vermikomposta pomešanih sa zemljištem, pri različitim količinama kombinacijama primene SC30, SC70, SC120 i SV30, SV70 SV120, tokom 21 dan. Početne pre inkubacijske analize kompostnog materijala korišćenog za eksperiment pokazale su da i kompost i vermikompost imaju visok sadržaj hranljivih sastojaka. Rezultati istraživanja pokazuju da su različite količine unetog komposta i vermikomposta u zemljište imale značajan uticaj na spor, postepen proces oslobađanja, hranljivih materija, što ukazuje na dugoročni efekat koji organsko đubrivo može da ima na status plodnosti zemljišta

Assessment of radioactivity and heavy metals in water sources from Artisanal mining areas of Anka, Northwest Nigeria

This study assessed the health risk associated with water sources in the artisanal and local mining areas of Anka, Northwest Nigeria. The evaluation of radioactivity concentration was carried out using a gas flow proportional counter while the carcinogenic and non-carcinogenic risks of heavy metals exposure were also evaluated. The concentrations of Cd, Co, Cu, Fe, Hg, Ni, Pb and Zn were measured using the microwave plasma atomic emission spectrometer. The mean annual effective dose for α- and β- emitters for children were 10.12 and 14.63 µSvy−1, respectively and those of adults were 22.94 and 30.51 µSvy−1 for α- and β- emitters, respectively. The mean values of lifetime cancer risk for children and adults were 2.73 × 10−4 and 1.26 × 10−4, respectively. The mean concentrations of heavy metals in descending order show the trend as Pb > Fe > Zn > Hg > Cu > Ni > Co > Cd > Cr. The mean concentrations of Fe, Hg, and Cd were above the WHO permissible limits of 0.200, 0.100 and 0.003 mgL−1, respectively. The hazard index of heavy metal evaluated in this study for children was 7.43 while that of adults was 1.27, which are higher than the limit of 1. The cancer risk due to heavy metal was 1.55 × 10−3 for children and 2.65 × 10−4 for adults; these values are higher than USEPA safe limits. The carcinogenic and non-carcinogenic risks from heavy metal are of concern and should be considered for continuous monitoring and remediation