Potassium supply rate as measured by exchange membranes in a calcareous sand
Woods, M.S., F.S. Rossi and Q.M. Ketterings. 2006. Applied Turfgrass Science doi:10.1094/ATS-2006-0323-01-RS
Abstract
Cation exchange membranes [Plant Root Simulator
(PRS™) probes] were used to evaluate the K supply rate of a
calcareous sand putting green. Creeping bentgrass [Agrostis
stolonifera var. palustris (Huds.) Farw.] leaf K content
was used as an indicator of K bioavailability. On all 14 measurement
dates in 2002 and 2003, the K supply rate increased in experimental
plots to which K fertilizer had been applied. On 9 of the 12 dates
when leaf samples were collected, K content in leaf samples increased
with K supply rate. We conclude that K supply rate is a meaningful
indicator of K bioavailability, and exchange membranes offer potential
for assessment of in situ variability in K supply. However, the
sensitivity of the exchange membranes to changes in soil K supply over
time presents obstacles to simple interpretation of supply rate
measurements.
Key Words
fertilization, potassium, putting green, supply rate, turf grass
