These tests are designed to measure the plant useable nutrients on a specific site, stand or tract. Soil sample results allow a resource manager to look at all of the available nutrients in a soil sample . Foliar samples are treated in much the same way as soil samples in terms of testing. These tests give resource managers a tool for evaluating prescriptions of needed macro-nutrients by analyzing what the tree foliage is currently holding compared with what the tree should be holding under optimum conditions. The University of Georgia has a web site that provides information for taking foliar samples .
Aircraft are the only means of application in rugged terrain and unthinned mid-rotation stands.
Trucks, tractors and skidders can be used for at planting applications and in thinned stands where terrain permits. The goal of application should be an even coverage of the site with the prescribed fertilizer at the prescribed rate. In numerous pilot blind ground samples, the variations between actual rates and prescribed rates were so small that sampling was canceled to better utilize the labor force at hand. It is important to note that any fertilizer application should coincide with a weed control application designed to control weed species present on the site. Most weeds are much more efficient at taking up and using fertilizers than are trees.