QUALITY COMPARISON OF DIFFERENT COMPOSTS REGISTERED BY GOVERNMENT OF PUNJAB UNDER FCO 1973

Abstract

Composts are mostly prepared from mixed municipal solid waste and due to probable chance of heavy metals contamination these can pose a great threat to environment by polluting our soils and subsequent insertion into food chain to cause severe ill effects on health. The present study was designed to assess quality of 13 licenced composts/organic amendments regarding plant nutrients and heavy metals contents manufactured by different companies. These products were collected randomly. Chemical analysis for basic nutrients i.e. nitrogen (N), phosphorus (P2O5), potassium (K2O), organic matter (OM), heavy metals namely cadmium (Cd), chromium (Cr) and lead (Pb) was carried out in the year 2012. The results were compared with national standard to determine product status. Organic matter values in all samples ranged from 11.9 to 70.9 percent. Three products with trade names of Taqatwar, Zameen Dost and Agrolizer manufactured by Green Force Fertilizers (Pvt). Ltd, National Fertilizer Marketing and Kanzo AG Multan, respectively were substandard with respect to standard value of 25 percent organic matter as established by Agriculture Department. Among macronutrients, total nitrogen contents ranged from 0.8 to 4.3 percent in all these samples which contained nitrogen above the minimum required value of 0.6 percent. Regarding phosphorus and potassium concentrations, one sample of Lahore Compost local (Zameen Dost) and one of Agro Partner (Simba) was found deficient having 0.4% P2O5 and 0.07% K2O against standard values of 0.5% and 0.08%, respectively. Considering heavy metals Cd and Cr as contaminants, all samples were found within permissible limit of 1.0 and 300 mg/kg, respectively whereas three samples of Elegant Agro, Bioman Chemical & Fertilizer and Agri Com Int. with trade names of Orgevit Plus, FertePlus and Biocom Super, respectively were found contaminated with lead having values higher than permissible limit of 1.00 mg/kg. This situation demands sound management/policy for manufacturing of composts to ensure a safeguard to the environment.