Root activity in creeping bentgrass thatch as measured by 32P and 33P

Abstract

A soil sample taken for chemical analysis should be representative of the growing medium of the plant. Turfgrasses often have thatch layers between the zone of green vegetation and the soil surface, and this thatch layer is generally discarded in the process of soil analysis. These thatch layers contain both roots and nutrient elements. If turfgrass roots are actively involved in removing nutrignts from the thatch, there may be advantages to including it with the soil for testing purposes. In the present investigation, two radioactive isotopes of phosphorus (³²P and ³³P) were used to separately label the thatch layer and the underlying soil of creeping bentgrass (Agrostis palustris Huds. ‘Penncross'). The roots of creeping bentgrass were found to simultaneously remove phosphorus from the thatch and from the underlying soil.

If the soil samples taken from turfgrass areas are to be truly representative of the soils capacity to supply nutrients, the thatch should be retained with the samples. Further investigations should be conducted to determine the feasibility of including the thatch in the chemical analysis process.