@article{heitman_castillo_smyth_crozier_wang_heiniger_gehl_2017, title={Nitrogen Fertilization Effects on Yield and Nutrient Removal of Biomass and Sweet Sorghum}, volume={109}, ISSN={["1435-0645"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85023770813&partnerID=MN8TOARS}, DOI={10.2134/agronj2016.12.0710}, abstractNote={Core Ideas
During the 4‐yr period of this trial, N fertilization increased dry matter yield in 2 out of 4 yr for biomass sorghum and there was no effect on dry matter yield of sweet sorghum.
High DM yield supports sorghum as a bioenergy crop, however, the relatively low nutrient removal rate may limit its utilization in nutrient‐rich environments such as spray fields.
Greatest dry matter yields achieved were ∼18.5 Mg ha−1 at a N fertilization rate of 67 kg N ha−1 yr−1 for biomass sorghum.
Sorghum [Sorghum bicolor (L.) Moench] can be used as bioenergy crop for either biomass or sugar yield. Dry matter (DM) yield and nutrient removal information is needed if sorghum is to be planted in high‐nutrient receiving areas such as swine (Sus scrofa domesticus) spray fields. The objectives of this 4‐yr experiment (2012 through 2015) were to determine the effect of five N fertilization rates (0, 67, 134, 201, and 268 kg N ha−1 yr−1) on DM yield and nutrient (N, P, and K) removal of cultivars Blade ES5200 (biomass) and M81‐E (sweet). The DM yield of ES5200 plateaued at 18.5 and 18.9 Mg ha−1 in 2012 and 2014, respectively, when N rate was 67 kg ha−1. There was no N fertilization effect on DM yield of M81‐E, which were 11.1 and 15.0 Mg ha−1 in 2012 and 2014, respectively. Early season excess rainfall in 2013 and 2015 negatively affected yield of both sorghums. Nutrient removal for ES5200 was 87 to 139 kg N ha−1, 20 to 23 for kg P ha−1, and 187 to 205 kg K ha−1. For M81‐E, nutrient removal was 52 to 118 kg N ha−1, 8 to 20 for kg P ha−1, and 92 to 156 kg K ha−1. Sorghum cultivars responded differently to N fertilization. High DM yield supports sorghum as a bioenergy crop, however, the relatively low nutrient removal rate may limit its utilization in nutrient‐rich environments such as spray fields.}, number={4}, journal={AGRONOMY JOURNAL}, author={Heitman, Adam J. and Castillo, Miguel S. and Smyth, T. Jot and Crozier, Carl R. and Wang, Zan and Heiniger, Ron W. and Gehl, Ronald J.}, year={2017}, pages={1352–1358} }
 @article{wang_heitman_smyth_crozier_franzluebbers_lee_gehl_2017, title={Soil Responses to Bioenergy Crop Production in the North Carolina Piedmont}, volume={109}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2017.02.0068}, abstractNote={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.}, number={4}, journal={AGRONOMY JOURNAL}, author={Wang, Zan and Heitman, Joshua L. and Smyth, T. Jot and Crozier, Carl R. and Franzluebbers, Alan and Lee, Sage and Gehl, Ronald J.}, year={2017}, pages={1368–1378} }
 @article{wang_smyth_crozier_gehl_heitman_2017, title={Yield and Nutrient Removal by Bioenergy Grasses on Swine Effluent Spray Fields in the Coastal Plain Region of North Carolina}, volume={10}, ISSN={1939-1234 1939-1242}, url={http://dx.doi.org/10.1007/S12155-017-9856-1}, DOI={10.1007/s12155-017-9856-1}, number={4}, journal={BioEnergy Research}, publisher={Springer Nature}, author={Wang, Zan and Smyth, T. Jot and Crozier, Carl R. and Gehl, Ronald J. and Heitman, Adam J.}, year={2017}, month={Jul}, pages={979–991} }
 @article{wang_bell_penn_moss_payton_2014, title={Phosphorus Reduction in Turfgrass Runoff Using a Steel Slag Trench Filter System}, volume={54}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2013.10.0667}, abstractNote={ABSTRACTExcessive concentrations of P can lead to the deterioration of surface waters through eutrophication. This study was conducted to test the effectiveness of a trench filter system for P removal from runoff and to determine the effect of P fertilizer on P losses in runoff from bermudagrass [Cynodon dactylon L. (Pers.)]. A total of 12 plots on a uniform 5% slope covered with ‘Astro’ bermudagrass mowed at 38 mm were used to collect pre‐ and postfiltered runoff from 14 natural or simulated precipitation events that occurred from March through September 2012. Runoff filtered by steel slag contained from 14.2 to 49.2% lower dissolved P concentrations than runoff filtered through an inert gravel control. The P concentrations in runoff from fertilized plots were always greater than unfertilized plots. The difference between P concentrations from the fertilized and unfertilized treatments tended to decline with each runoff event from 13.1 mg L–1 in an initial event after fertilization to 1.6 mg L–1, 133 d and nine runoff events later. Trench filter systems could be used to remove a portion of the P in runoff from turfgrass areas.}, number={4}, journal={CROP SCIENCE}, author={Wang, Zan and Bell, Gregory E. and Penn, Chad J. and Moss, Justin Q. and Payton, Mark E.}, year={2014}, pages={1859–1867} }