Performance of switchgrass and Miscanthus genotypes on marginal land in the Yellow River Delta

Abstract

The lignocellulosic biomass derived from Miscanthus Anderss. and switchgrass (Panicum virgatum L.) has been widely investigated; however, large−scale production is obstructed by the lack of suitable genotypes for their growth on marginal land. To breed new varieties that can adapt to specific marginal lands, a four-year (2014−2017) field experiment was conducted using switchgrass and 12 Miscanthus genotypes on marginal land in the Yellow River Delta (YRD). The performances of Miscanthus and switchgrass were evaluated and climatic factors limiting their biomass yield were identified. During each year of the trial, 13 genotypes were harvested in winter and their biometric characteristics (biomass yield, plant height, stem diameter, and tiller number) were measured. Quality parameters (cellulose, hemicellulose, lignin, and ash) were determined in the third growing season. The three-year average biomass yield of switchgrass was 5.66 Mg/ha. The three-year average biomass yield of the 12 Miscanthus genotypes ranged from 1.99 to 32.09 Mg/ha. The biomass yields of M. lutarioriparius and hybrids were significantly higher than that of switchgrass, however, these were more sensitive to rainfall than switchgrass. No significant difference was found between the ash contents of M. lutarioriparius, M. sacchariflorus, and switchgrass. The contents of hemicellulose, cellulose, and lignin were 377.69, 526.10, and 109.33 g/kg, respectively for switchgrass, and 247.56−391.28 g/kg, 473.52−619.85 g/kg, and 83.03−132.88 g/kg, respectively, for Miscanthus. Combining biomass yield and quality, the potential ethanol productions of M. lutarioriparius and Miscanthus hybrids were higher than that of switchgrass, and the Miscanthus hybrid h1 reached 14,600 L/ha. The results of this study provide fundamental information for the development and utilization of biomass crops on marginal land in the YRD.