Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/20/2002
Publication Date: 5/28/2002
Citation: Reed, R.L., Sanderson, M.A., Allen, V.G., Zartman, R.E. 2002. Cadmium application and ph effects on growth and cadmium accumulation in switchgrass. Communications In Soil Science And Plant Analysis. 33(7&8):1187-1203. Interpretive Summary: Growing switchgrass for bioenergy requires nitrogen fertilizer. Alternatives to inorganic fertilizer are needed to reduce energy costs. Municipal sewage sludge may be an economical source of fertilizer nutrients, but heavy metals (such as cadmium) in the sludge may be a concern if it accumulates in switchgrass. Our research has shown that high hlevels of cadmium reduce switchgrass growth. Cadmium also accumulates in switchgrass, mainly in the roots. Maintaining the soil pH near neutral (7.0) will minimize cadmium accumulation in switchgrass.
Technical Abstract: Recent efforts have been initiated to develop switchgrass (Panicum virgatum L.), which requires nitrogen (N) for productivity, as a bioenergy crop. Alternatives to inorganic fertilizers are needed to reduce input costs and maintain a positive energy balance. Municipal sludge may be an economical source of N and other nutrients for biomass production, but switchgrass's response to heavy metals in the sludge is unknown. A study was conducted to determine the interaction of soil pH and Cd application on biomass accumulation and Cd allocation of switchgrass. 'Alamo' switchgrass was grown in pots at five soil pH levels (4.0, 5.1, 5.8, 6.6, and 7.3) and four soil Cd levels (0, 50, 100, and 200 mg Cd kg-1). Two hundred milligrams Cd kg-1 decreased biomass accumulation of all plant components by 95%. Cadmium concentrations of 900 mg kg-1 were found in root tissue of plants grown in soil with 200 mg Cd kg-1 and a pH of 4.0. Soil pH should be maintained near neutral to minimize Cd accumulation by switchgrass.