En greens åldrande

The success of a golf green construction cannot be fully judged until after some years after establishment when the green has been exposed to stress from players, maintenance and weather. This project aimed to investigate the changes of different biological, chemical and physical soil parameters in a green over a 6 year period. The green was built in 1999 as a research green at Fullerö Golf Club in the Mälar region in central Sweden. It was built according to USGA recommendations and included treatments with different levels of organic matter content (2, 3 and 4 % of weight) and two different types of organic amendment (fen peat and composted chicken manure mixed with Sphagnum peat). Changes in soil biological activity (C-mineralization), total C and N, nutrient elements, water holding capacity, porosity and bulk density were determined during the period 1999-2004. The effects on soil biological activity of different organic matter contents and qualities in the rootzone mix only lasted during the first year after establishment. Thereafter, the production of fresh organic matter residues, mainly roots, seemed to be the most important factor regulating the biological activity in the soil. Total C slightly decreased in all treatments, whereas there was a tendency for total N to increase in some of the treatments. The soil pH and concentrations of all studied nutrients except phosphorus increased in all treatments,. The rootzone with 4% peat withstood compaction better than the rootzones with 2% or 3% peat. There was a significant loss of pores 100-600 μm in size over the 6 year period, especially in treatments with 2% and 3% organic matter content. This dramatically decreased the saturated hydraulic conductivity (Ksat). Ksat was more related to the presence of pores >100 μm (air-filled porosity) than to organic matter content in the soil mix in the 6 year old green. Turf grass production was highest in the rootzones with 4% peat and lowest in rootzones with 3% peat. There were no difference in root distribution between the different rootzones 6 years after construction.