The effect of a sandy soil amendment with municipal solid waste (MSW) compost on nitrogen uptake efficiency by plants

The purpose of this work was to determine the influence of municipal solid waste (MSW) compost application on soil properties, nitrogen availability to plants and its uptake efficiency. The paper deals with results of a three-year field experiment where two different MSW composts were non-recurrently applied to sandy soil at rates of 18,36 and 72 t ha(-1) (dry mass). Plots without fertilisation as well as plots fertilised each year with mineral forms of NPK were the controls, and spring triticale was cultivated in a monoculture on all plots as a test plant. Soil properties, plant yield and nitrogen content in grain and straw were determined at harvest, and on this basis the applied nitrogen uptake efficiency was calculated. During the first year, only the plots with the highest dose of the better-quality compost had yields similar to the plots fertilised with mineral NPK. Following the years of the experiment, all the plots treated with compost had distinctly lower yields than the plots fertilised with mineral NPK. That decrease was accompanied by a decrease in the nitrogen content in straw and grain, in spite of the fact that the soil material indicated a similar content of total nitrogen to those fertilised with NPK. This indicates that organic matter brought into the soil with MSW compost was intensively mineralised, releasing a considerable amount of nitrogen. However, the plant response indicated a shortage of the plant-available forms of this element. The efficiency of compost-originated nitrogen uptake by plants was very low, at less than 7% of the applied nitrogen. This indicates that plants can take up only a limited amount of nitrogen released from the compost, while considerable amounts are emitted into the atmosphere. (C) 2013 Elsevier B.V. All rights reserved,