Tree-based mulches influence soil properties and plant growth

Abstract

The objective of this research was to determine the response of soil properties and plant growth to the application of various tree-based mulches and provide information specifically regarding attributes of eastern redcedar mulch (Juniperus virginiana). Eastern redcedar mulch, cypress mulch (Taxodium distichum), pine bark nuggets [southern yellow pine (Pinus sp.)], pine mulch (southern yellow pine), hardwood mulch [maple (Acer sp.), oak (Quercus sp.)], reddyed mulch [maple, poplar (Populus sp.)], and grand eucalyptus mulch (Eucalyptus grandis), as well as two nonmulched controls (with and without chemical weed control) were tested. Volumetric soil moisture, soil nutrients, soil temperature, weed growth, and growth and survival of planted annuals and trees were measured. Compared with nonmulched controls, mulch treatments generally increased growth of annuals and trees and decreased weed growth, but few differences in measured variables were noted among mulch types. Mulched plots had greater volumetric soil moisture than nonmulched plots during extended periods without rainfall. Mulched plots had more moderate diurnal soil temperatures than nonmulched control plots. Soil pH and soil potassium increased with hardwood mulch during the 2 years of the study. These results indicate tree-based mulch benefits plant growth and survival by maintaining greater soil moisture, decreasing competition from weeds, and moderating soil temperatures compared with not using mulch. Eastern redcedar mulch provides similar benefits as other common wood mulches and is a viable forest product.