Municipal sewage sludge is often used in compost production for agriculture. Composting sediments, which include structure-forming materials, result in the formation of matter rich in organic substances and nutrients that can be used as a component of horticultural substrates, being an alternative to peat. The aim of this research paper is to assess the impact of substrates containing municipal sewage sludge compost on Ntot., P, K, Ca, Mg and S levels in the leaves and roots of Impatiens walleriana Hook. A two-year experiment used four types of compost; in the first year the tests were conducted after a 7-month period of compsting and in the second year - after 18 months. The composition of the compost material was as follows: compost I - 70% municipal sewage sludge, 30% rye straw; compost II - 70% municipal sewage sludge, 30% coniferous tree sawdust; compost III - 35% municipal sewage sludge, 35% potato pulp, 30% rye straw; compost IV - 35% municipal sewage sludge, 35% potato pulp, 30% coniferous tree sawdust. During the first and second year, five experimental sites were used: four substrates with 50% of the tested compost and 50% sphagnum peat and one sphagnum peat reference substrate with a 2.5 g dm-3 dose of Azofoska multipurpose fertiliser. After 12 weeks of Impatiens walleriana cultivation, the recorded level of total nitrogen, calcium, magnesium and sulphur in the leaves was lower than the optimal range of the macrocomponent content recommended for this species. The levels of phosphorus and potassium were an exception. Impatiens cultivated in substrates with compost after a 7-month decay period contained 1.7 times more nitrogen and 1.8 times more potassium in leaves; they had a similar phosphorus and sulphur content but less calcium and magnesium than plants cultivated in the compost substrates after an 18-month maturing period. The roots of Impatiens contained more calcium than leaves in both years of the study. The nutrients supplied in the substrates and through top dressing fertilisation were insufficient to achieve the best cultivation results for Impatiens walleriana.

19.1.2014