Influence of simulated traffic and roots of turfgrass species on soil pore characteristics

• Traffic test with four turfgrass species.
• Soil physical and hydraulic properties and root parameters were measured.
• Traffic treatment did not affect the available and productive water content.
• Higher root biomass have a beneficial effect on the soil water retention.

A field experiment was conducted during the period of 2011 to 2012 to study the effect of traffic on physical properties of soil when different turfgrass species were cultivated. Experimental plots were established with three replications in a split-plot design with species as a main plot and traffic treatment as a subplot. The traffic treatment was applied to the turfgrass using Brinkman traffic simulator (BTS). Two levels of treatments were applied: non-trafficked vs. trafficked. Four grass species were used, Festuca arundinacea, Festuca rubra, Poa pratensis and Lolium perenne. The BTS compaction was applied every week since the beginning of April to the end of November. Physical parameters of soil, bulk density, total porosity and penetration resistance were determined. Based on the water retention characteristic curve, the pore size distribution, available water content (AWC), productive water content (PWC) and relative water capacity (RWC) were calculated. Root parameters like length density (RLD) and dry matter (RDM) were determined as well.Both experimental factors, grass species and BTS compaction, changed soil physical parameters, penetration resistance, bulk density and total porosity. These changes were results of modification of pore system. Large pores were modified by grass species and BTS compaction. However, storage pores of 0.5–50 μm in diameter were affected only by grass roots. This reflected in the water retention characteristics of the soil. The RWC ratio indicated poor water conditions prevailing in the soil except trafficked two grass species, namely F. arundinacea and L. perenne. The highest water retention in the range of the AWC was noticed for F. arundinacea (0.191 cm3 cm− 3) and for L. perenne (0.187 cm3 cm− 3). Significantly lower AWC was recorded for F. rubra and P. pratensis, 0.151 and 0.141 cm3 cm− 3, respectively. The similar relationship was also observed for the PWC. It was found that changes in the AWC and PWC can be explained by the root parameters. The higher root biomass concentration in the soil had a beneficial effect on the soil water retention. It can be concluded that F. arundinacea and L. perenne can be recommended for turfgrasses with irrigation system where the water resources are limited.