Over a 4-yr period fertilizers having three N and five K levels in a factorial arrangement were applied in a replicated, randomized complete block design to coastal bermudagrass (Cynodon dactylon L.) growing on a Pembroke silt loam just north of Fayetteville. In the spring of the fifth year (1972) soil samples were taken from a 3.67-m profile of each plot. Nine depth samples from the profile of each plot were analyzed for exchangeable K and Ca. Potassium fertilizer, especially at the higher rates, and where no N was applied, greatly increased exchangeable K levels only in the top 45 cm of the profile; however, exchangeable Ca levels were decreased markedly in these same upper soil layers, and increased greatly at lower levels in the profile. The first increment of N reduced this effect of K fertilizer on exchangeable Ca, probably because of increased plant growth that resulted from N fertilization; this increased growth removed a larger portion of the fertilizer K. At the higher N rate the net change in exchangeable Ca was greater, but more varied between K treatments, with the highest level of N and K resulting in a net loss of Ca from the 3.67-m profile sampled.
Allured, R. A. and Thompson, Lyell F.
"Effects of Intensive N-K Fertilization on Exchangeable Ca and K in a Soil Profile,"
Journal of the Arkansas Academy of Science: Vol. 27
, Article 6.
Available at: http://scholarworks.uark.edu/jaas/vol27/iss1/6