Effects of hog manure application on the nutrition and growth of hybrid poplar (Populus spp.) and on soil solution chemistry in short-rotation woody crops

Abstract

Hybrid poplar plantations were fertilized with hog manure at different manure supply rates for 6 years. In order to evaluate this practice in agricultural landscapes, we studied the effects of increasing manure supply on the growth and nutrition of three hybrid poplar clones and on soil solution chemistry at depths of 20 and 40cm. More specifically, experimental plantations were established in nine fallow fields, each of which was divided into four plots fertilized with one of four levels of hog manure supply (i.e. 0, 40, 60 or 80kgha−1 in total N). Manure application significantly increased tree growth and C sequestration, although growth was not correlated with manure supply rates. Vector analysis of the nutritional status of trees suggests that N and K likely were limiting nutrients for tree growth on unfertilized plots. Our results further suggest that manure application in hybrid poplar plantations did not cause important changes in soil solution NO3− and PO43− concentrations. From a manure management perspective, this could indicate that hog manure can be used to increase the productivity of tree plantations without creating major concerns about potential damage to aquatic ecosystems, especially if plantations are located away from water bodies.