Project: Developing Agroforests For Production of Bioenergy in the LMAV
Project
Objectives
The purpose of this project is to develop economically and ecologically viable agroforest systems for producing cellulosic bioenergy crops on marginal agricultural land in the Lower Mississippi Alluvial Valley (LMAV). To accomplish this, we are establishing agroforest systems composed of diverse mixtures of cottonwood trees (Populus deltoides L.) and switchgrass (Panicum virgatum L.) at three sites of marginal soil quality located along the LMAV from northeast Arkansas through northeast Louisiana. To understand the cellulosic biofuel production potential and ecological sustainability of these systems, we are: (1) assessing biomass and potential biofuel yields, (2) determining the investment potential of these systems by monitoring management costs and potential revenues from biomass production, (3) determining the potential for these systems to sequester carbon (4) quantifying their impacts on water quality by monitoring nitrogen concentrations in water draining from these systems, (5) evaluating impacts on soil quality as indicated by soil nitrogen and carbon dynamics, and (6) assessing the influence of these systems on wildlife by measuring habitat characteristics and monitoring small mammal populations. This is a long-term study slated to occur over a 5 to 10 year period.
Need for proposed research project
This project is the first comprehensive study to simultaneously 1) evaluate the potential of agroforest systems to provide biofuel feedstocks, 2) combine cottonwoods trees and switchgrass in one cropping system to produce cellulosic biomass, and 3) assess the potential of cottonwood-switchgrass mixtures grown on marginal agricultural land in the LMAV to supply both cellulosic biomass and ecosystem services (i.e., carbon sequestration, wildlife habitat, improved soil quality, and watershed protection). Marginal agricultural lands targeted by this study are poorly drained or have low inherent fertility and thus are not well suited for traditional agricultural production or crops. Biofuel feedstock production systems currently under consideration in the LMAV involve the planting and cropping of a single species. Although these cropping practices may provide substantial amounts of biofuel production, the sustainability of these agronomic systems and their ability to provide a diversity of ecosystem services is questionable. Cottonwood-switchgrass agroforests could be a flexible and innovative cropping system for providing cellulosic feedstocks as well as ecosystem services. A wide range of cottonwood and switchgrass mixtures could be employed to provide an optimal suite of services along with high cellulosic production to meet a variety of management objectives, social constraints, and soil/site conditions. The proposed study is unique in that it utilizes a compositional gradient of cottonwood and switchgrass to explore the impacts of these different mixtures on cellulosic production and ecosystem services. Unlike studies that assess only the productive capacity of biofuel cropping systems, this study will also evaluate the economic feasibility of these agroforest systems. Agroforests may have the potential to dramatically increase the biofuel production capacity for the U.S., improve the economies of the economically faltering rural communities of the LMAV, and enhance soil, water, and wildlife habitat quality.
There are currently several MS Graduate Assistantships.
Click to see a powerpoint presentation of the project
Generalized plot diagram Plot Layout at Rowher Site
