Modeling Water Quality Impacts of Growing Corn, Switchgrass, and &amp;lt;i&amp;gt;Miscanthus&amp;lt;/i&amp;gt; on Marginal Soils

Mark A Thomas,Laurent M Ahiablame,Bernard A Engel,Indrajeet Chaubey

doi:10.4236/jwarp.2014.614125

Abstract

The goal of the study was to model water quality impacts of growing perennial grasses on marginal soils. The GLEAMS-NAPRA and RUSLE models were used to simulate long-term surface runoff, percolation, erosion, total phosphorus (TP), and nitrate (NO3-N) losses associated with the production of corn-based bioenergy systems (i.e. conventional tillage corn and corn grain plus stover removal), switchgrass and Miscanthus on three marginal quality soils and one good quality soil in Indiana. Simulations showed that switchgrass and Miscanthus had no effect on annual runoff, but decreased percolation by at least 17%. Results also suggested a potential for reduction in erosion for Miscanthus across the soil types examined when compared to corn-based bioenergy production. The production of switchgrass and Miscanthus did not have significant effects on the simulated TP and NO3-N losses in runoff compared to corn production systems. Nitrates leached from fertilized Miscanthus production were approximately 90% lower than NO3-N leached from the production of fertilized switchgrass and corn systems. Additional studies are needed to better understand the hydrology, erosion and nutrient responses of Miscanthus and switchgrass production to meet bioenergy demands.

Highlights

IntroductionThere is increased interest for biofuel production on marginal lands (i.e. low quality soils), as this avoids competition with food crops [5]-[8]
Over the past few years, the interest to intensify renewable energy production resulted in increased attention forThere is increased interest for biofuel production on marginal lands, as this avoids competition with food crops [5]-[8]
The GLEAMS-NAPRA and RUSLE models were used to simulate long-term surface runoff, percolation, erosion, total phosphorus (TP), and nitrate (NO3-N) losses associated with the production of corn-based bioenergy systems, switchgrass and Miscanthus on three marginal quality soils and one good quality soil in Indiana

Summary

Introduction

There is increased interest for biofuel production on marginal lands (i.e. low quality soils), as this avoids competition with food crops [5]-[8]. Research showed that biofuel feedstocks are capable of growing on soils with naturally poor conditions (for agriculture) due to their high efficiency for water and nutrient use [9]-[13]. The most popular crops for biofuel energy production in the United Sates include corn, soybeans, and perennial grasses such as switchgrass (Panicumvirgatum), big bluestem (Andropogongerardii), Indiangrass (Sorghastrumnutans) and Miscanthus × giganteus [14] [15]. The perennial grasses considered consist of switchgrass and Miscanthus due to their potential adaption to Indiana’s climatic conditions. Miscanthus × giganteus is a sterile perennial grass, relatively new to the United States and has high biomass yield potential [19]. The cold-tolerant Miscanthus hybrid is capable of retaining high C4 photosynthetic activities at temperatures as low as 8oC, with increased productivity potential under increasing precipitation, making it suited to the rain-fed Midwest regions [19]

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