Differentiating characteristics of sports surface profiles

The soil profiles of our sports surfaces have particularly different characteristics to other agricultural soils. On the one hand, they follow the specifications given by organisations such as the USGA, with textures of sandy with specific granulometric curves, where Infiltration rates will generally be higher as we move to the right in these curves.

Both the accumulation and fixation of CO2, felt or thatch, as well as the breathing Heterotrophic conditions in our sports turf are governed by maintenance practices and have been estimated to range from 31 g C/m2 and year for unmaintained turf surfaces, to 922 g C/m2 and year for areas with fertilisation and mowing residue input (source: Milesi et al., 2005). These sports surfaces produce more CO2 than agricultural soils and natural ecosystems because they contain more organic matter in the soil. (source: Kaye et al., 1997). Today there are numerous new technologies for the disposal of organic matter.

There are records of very high CO2 values in the soil profiles of golf courses and football pitches. Values up to 3 and 4%, much higher than the atmospheric 0.03%, are a consequence of the intensive maintenance and high growth rates that occur on these sports surfaces. (source: Lee et al., 1997).

Obear and Soldat (2015) studied the vertical distribution of Total Dissolved Inorganic Carbon in 28 USGA greens. They wanted to check whether calcium carbonate accumulation occurred, as it usually happens in agricultural soils, as a consequence of irrigation with more or less hard water with high bicarbonate and carbonate contents (resulting from the dissolution of CO2 in the soil). The study presented values different from those occurring in agriculture..

It turned out that when the Soil pH was below 7.8 the soil had very low amounts of inorganic carbon, while at pH values above 7.8 the amounts of inorganic carbon were variable. Furthermore, in most of the samples the pH increased with depth, with the highest values in the lower profile. Those soils with acid pH did not show traces of inorganic carbon, although from alkaline values, in particular from pH values above 7.8 (determined by statistical analysis on the samples studied) the probability increased, although there were also cases with no carbonate present.

Common assumptions such as the accumulation of calcium and magnesium carbonate crusts in USGA profiles and the associated physical infiltration problems due to irrigation with very alkaline water have not been proven true on USGA greens, and are being challenged, as these soil profiles are very different from agricultural ones.

(source: Carrow et al., Ellis, 2009; Fidanza, 2006; Harivandi, 1999; Simmons, 2010)

The high density of foliage and other inherent characteristics of these sports constructions mean that these effects, common in agriculture, are not common on USGA greens. (Obear et al., 2015). The effects of the different fertilisers used on sports surfaces on the chemical characteristics of the pore water are very strong, increasing or decreasing the value of the pH of the soil depending on the acidic or basic nature of each fertiliser. This is a function of the low buffering capacity of these soil profiles. (Obear et al., 2015).

Due to the particular characteristics of the soils of our sports surfaces, for an adequate and sustainable management, including irrigation and fertilisation, it is convenient to study which are the most relevant processes in each place and to build a model that allows us to advise on such management. Ask for advice at info@tiloom.com to learn more about how to manage your sports surfaces.