2017 journal article

Soil Responses to Bioenergy Crop Production in the North Carolina Piedmont

AGRONOMY JOURNAL, 109(4), 1368–1378.

By: Z. Wang n, J. Heitman n, T. Smyth n, C. Crozier n, A. Franzluebbers n, S. Lee*, R. Gehl

co-author countries: United States of America 🇺🇸
Source: Web Of Science
Added: August 6, 2018

Core Ideas Three bioenergy and two traditional cropping systems were compared in the North Carolina Piedmont. Bioenergy crops sorghum, switchgrass, and giant mischanthus produced large yields. Removal of N, P, and K was least for perennial bioenergy crops. Perennial bioenergy crops had slightly poorer soil physical conditions after 3 yr. Organic C pools were greatest with giant miscanthus and fescue. Bioenergy crops are potential alternatives to traditional row‐crop and pasture/hay systems. A trial comparing effects of bioenergy to traditional production on soil properties was established in 2012 under no‐till in the North Carolina Piedmont. Five cropping systems included: giant miscanthus ( Miscanthus × giganteus ), switchgrass ( Panicum virgatum L.), biomass sorghum ( Sorghum bicolor spp.), tall fescue [ Schedonorus arundinaceus (Schreb.) Dumort.], and corn ( Zea mays L.)/wheat ( Triticum aestivum L.)/soybean ( Glycine max L.) rotation. Soil samples were collected before and 3 yr after trial establishment. Sorghum produced average yield of 21.5 Mg ha −1 in 2012 to 2015. Miscanthus and switchgrass reached yield plateaus of 21 and 15 Mg ha −1 , respectively, and removed significantly less N, P, and K than other crops, due to their rhizome systems and lower fertilizer requirements. They did not, however, demonstrate advantages over annual crops in soil physical properties. Soils under miscanthus and switchgrass had the least macropores and lowest saturated hydraulic conductivity. Summed to 30‐cm soil depth, miscanthus maintained similar soil organic C as with tall fescue (58.6 vs. 55.0 Mg C ha −1 ), whereas soil organic C under sorghum and switchgrass were lowest (average of 49.5 Mg ha −1 ). Microbial biomass soil C under miscanthus (0–12‐cm depth) was significantly greater than under annual crops. Negative effects of switchgrass on soil physical properties and organic C and N might have been due to tillage required for establishment. Typical bioenergy crops do not appear to have major negative or positive effects on soil properties in the North Carolina Piedmont.