On a Wrightsville-Vidrine silt loam flatwoods in southwest Louisiana, six-year-old slash pines (Pinus elliottii Engelm. var. elliottii) planted on the better drained Vidrine-pimple mounds Vidrine-like ridges were nearly four times larger than pines planted in the poorly drained Wrightsville depressions. Site preperation treatments did not affect tree growth on the better drained sites. In the poorly drained depressions, pines planted on beds were 37 percent taller and averaged 49 percent more volume per tree than pines planted on harrowed plots. Fertilization did not increase yields on the poorly drained sites. On the better drained sites, pines fertilized with triple superphosphate were 24 percent taller and averaged 84 percent more volume per tree than unfertilized pines.
Haywood, James D. 1983. Small topographic differences affect slash pine response to site preparation and fertilization. Reprinted from the Southern Journal of Applied Forstry Vol 7, No 3, August 1983