RESPONSE OF TURFGRASS GROWTH IN A BLACK CHERNOZEMIC SOIL AMENDED WITH MUNICIPAL SOLID/BIOSOLID WASTE COMPOST

Abstract

High transportation cost is a barrier which prevents land application of compost far away from where the compost is produced. As a result, use of compost in lawns is becoming a popular alternative in municipalities where compost is produced from municipal solid/biosolid waste. A four-year (2002 to 2005) field experiment was conducted on turfgrass [20% Kentucky Blue (Poa pratensis L.) + 80% Creeping Red Fescues (Festuca rubra L.)] grown on a Black Chernozem soil near Edmonton, Alberta, Canada, to determine the effect of rate and frequency of spring application of compost (prepared from soild/biosolid waste of city of Edmonton) on biomass, sward color, concentration and uptake of nutrients of sward, and soil chemical properties. There were three compost treatments: 50 Mg ha−1 annual; 100 Mg ha−1 (1st year) + 50 Mg ha−1 (2nd year) split, and 150 Mg ha−1 once in three years (2002, 2003 and 2004) applications. In addition, there were check (no fertilizers or compost) and annual nitrogen-phosphorus-potassium-sulfur (NPKS) fertilizer application (100 kg N + 20 kg P + 42 kg K + 20 kg S ha−1 annual) treatments. In the fourth year (2005), residual effect of applied compost on turfgrass growth was determined. Annual application of compost at 50 Mg ha−1 had more green color of leaf, and higher sward N concentration and biomass production of turfgrass for prolonged periods than the check treatment. In comparison with annual application, high initial compost and split applications generated greater turfgrass growth only in the first two years, but produced higher cumulative biomass over the three- or four-year period. Both annual and cumulative biomass yields were highest in treatments receiving NPKS fertilizers. After four growing seasons, there was no residual mineral N in soil from both compost and NPKS fertilizer, and no residual sulfate-S in soil from NPKS fertilizer treatments. The amounts of extractable P and exchangeable K in soil were greater in compost treatments than in the NPKS fertilizer treatment. There was downward movement of extractable P into the 15–30 cm soil depth in one-time initial and split compost and NPKS fertilizer treatments, and of sulfate-S in all compost treatments. In conclusion, annual application of compost in spring at 50 Mg ha−1 is recommended for sustainable color and growth of turfgrass.