ABSTRACT
Composting is the controlled conversion of degradable organic products and wastes into stable products with the aid of microorganisms. The application of composting increases agricultural productivity and organic matter content of the soil, owing to the sufficient nutrient in the composted materials and the presence of plant growth-promoting organisms. This helps to ensure food security to a great extent. Aside usage as fertilizer, compost is useful in bioremediation, plant disease control, weed control, pollution prevention, erosion control, landscaping and wetland restoration. Composting also increases soil biodiversity and reduces environmental risks associated with synthetic fertilizer. Compost contains nutrients required by plants both in large proportions and relatively small quantities such as potassium, phosphorus, nitrogen, sulphur, chlorine, iron, manganese, molybdenum, and zinc. It is therefore pertinent to chemically analyse the mineral nutrients present in composted watermelon fruits. To carry out this chemical analysis, a sample of watermelon fruit bought in Ekosodin market, Ovia Northeast local government area, Benin City, Edo State was used. A fresh watermelon fruit was washed, cut into very small pieces and covered in a plastic container with tiny perforation of the cover. The whole set up was wrapped in polyethylene bag to generate heat and lower the amount of oxygen available in order to make the decomposition fast. The sample was allowed to stand for 21 days for complete decomposition. After this period, the water content of the sample was collected and taken to Laboratory for chemical characterisation after digestion using nitric perchloride, conc.suphuric acid while sterilised water and alga nutrient solution was used to carryout bacterial count in the compost waste water. Some of the minerals in the watermelon compost: calcium, magnesium, potassium, manganese, phosphates, sulphates, nitrogen, chloride, copper, minerals were analysed using AAS machine, titrimetry and UV-VIS spectrophotometer. The amounts of each of the minerals in the compost was recorded.
