EFFECT OF SEWAGE SLUDGE COMPOST TREATMENT ON CROP YIELD

Abstract

Due to the increasing number of sewage cleaning plants, the amount of sewagesludge also increases. We have to solve the environmentally sound disposal of thesludge. Results of many experiments show that sewage sludge and sewage sludgecompost can be recycled as nutrient suppling material in agriculture. Municipalsewage sludge compost could cause the occurrence and accumulation of toxicelements in the soil. A small-plot experiment with sewage sludge compost wasestablished in the spring of 2003. The applied compost contains 40% sewagesludge, 25% straw, 30% rhyolite, 5% betonite. The small-plot experiment was retreatedin the autumn of 2006, 2009, 2012and 2015. There are 4 treatments in fiveblocks, where the sewage sludge compost was applied at a rate of 0, 9, 18 and 27tha-1 and then ploughed into the soil. Triticale as autumn cereal, maize and greenpea as spring crops were sown in crop rotation every year. Plant samples werecollected before harvesting. In this paper the results of crop yield between 2010-2012 are presented. Crops of triticale and maize were higher in the treated plotsthan in control one in 2010 and 2011. Treatment effect was not observed on greenpea yield.The results show that the effect of applied compost doses depends onplant species and time. Our aim is to maintain this unique long-term experiment forstudying the composted sewage sludge as a nutrient and organic matter source,applying it similarly to the farmyard manure.