Hardwood growth and foliar nutrient concentrations best in clean cultivation treatments

Nine hardwood species were planted at a 3 m by 3 m spacing on a Mississippi River front soil (Aeric Fluvaquents) in western Mississippi and subjected to three intensities of cultural treatments. Because of the death of yellow-poplar during a severe spring flood (1973) and severe iron deficiency in three oaks caused from high soil pH, only five species are discussed in this paper. Periodic disking substantially increased heights, diameters, and survival of trees through 4 years. Disked plots had significantly lower soil N than mowed and control, while Mg was considerably higher in disked than control plots. Cultural treatments did not affect other measured soil nutrient levels.Trees growing on disked plots had significantly higher N and significantly lower P, K, and Mg concentrations than those in control plots. Foliar concentrations of K and Mg in disked and mowed plots were similar. Cultural treatments did not affect foliar Ca concentrations. Sweetgum had the lowest nutrient concentrations and cottonwood or green ash the highest for most nutrient elements tested. Other species were intermediate, and no ranking was readily apparent.