EFFECTS OF NITROGEN AND BIOLOGICAL MATERIALS ON DECOMPOSITION OF THATCH IN SPORTS TURFGRASS

In turfgrass, thatch is a tightly intermingled layer of living and dead stems, roots, rhizomes, plant crowns and other plant parts that develop between the layer of green vegetation and the soil surface. One method for preventing the formation of thatch to increase microbial activity in soil and to regulate the application of nitrogen fertilizers. The objective of this study was to evaluate the relative efficacy of biological dethatching materials and effect of nitrogen in decomposition of thatch in sports turfgrass. The treatments included T₁= Control; T₂= PHC biological material; T₃= Iranian-made biological material (IBM); T₄= Urea; T₅= Sulfur coated urea (SCU); T₆= PHC biological material+ urea; and T₇= IBM+urea. The experiment was carried out at the turfgrass nursery field of Azadi Sport Complex in Tehran (Iran) during 2004 and 2005. Experimental parameters determined on site included thickness of the thatch, turfgrass height and the color of the turfgrass leaves. Other parameters such as total N, chlorophyll content, and C:N ratio were determined at the end of the study in the laboratory. The ANOVA results indicated treatments were significantly different (=0.01) for thatch thickness, leaf-nitrogen content, C:N ratio, as well as the chlorophyll content, while plant height and leaf color were not affected by treatments. The results also showed that although treatments contain biological materials (T₂, T₃, T₆ and T₇) were effective in thatch decomposition, but the greatest reduction was observed with T₆.