Effect of Compost from By-Product of the Fishing Industry on Crop Yield and Microelement Content in Maize

A pot experiment was conducted to compare the effects of compost from fish waste with mineral and manure fertilization on the yield and chemical composition of the overground parts of maize (Zea mays L.). The experiment comprised two series: I – composts at a dose of 1 g of compost per pot, and II – composts with 0.5 g of urea. The treatments were conducted on the following types of composts: compost 1: fish waste (80% d.m.), sawdust (20% d.m.); compost 2: fish waste (80% d.m.), straw (20% d.m.); compost 3: fish waste (80% d.m.), bark (20% d.m.); compost 4: fish waste (79.3% d.m.), sawdust (19.7% d.m.), lignite (1% d.m.); compost 5: fish waste (79.3% d.m.), straw (19.7% d.m.); lignite (1% d.m.); compost 6: fish waste (79.3% d.m.), bark (19.7% d.m), lignite (1% d.m). The contents of Ni, Zn, Cr, Cu and Cd were deter-mined in an air-acetylene flame using the flame atomic absorption spectrophotometric method. The average crop yield of the overground parts of maize in the series without additional mineral fertilization and with mineral N-fertilization was higher compared to objects without mineral N-fertilization. The highest crop yield was noted in the case of compost containing fish waste and straw with addition of lignite and with bark and lignite. The addition of lignite to the compost mass in the series with mineral N fertilization had stronger influence on the content of cadmium, chromium, nickel and zinc in the overground parts of maize.