Mapping cropland waterway buffers for switchgrass development in the eastern Great Plains, USA

Abstract

Switchgrass (Panicum virgatum L.), a highly productive perennial grass, has been recommended as one potential source for cellulosic biofuel feedstocks. Previous studies indicate that planting perennial grasses (e.g., switchgrass) in high-topographic-relief cropland waterway buffers can improve local environmental conditions and sustainability. The main advantages of this land management practice include (i) reducing soil erosion and improving water quality because switchgrass requires less tillage, fertilizers, and pesticides; and (ii) improving regional ecosystem services (e.g., improving water infiltration, minimizing drought and flood impacts on production, and serving as carbon sinks). In this study, we mapped high-topographic-relief cropland waterway buffers with high switchgrass productivity potential that may be suitable for switchgrass development in the eastern Great Plains (EGP). The US Geological Survey (USGS) Compound Topographic Index map, National Land Cover Database 2011, USGS irrigation map, and a switchgrass biomass productivity map derived from a previous study were used to identify the switchgrass potential areas. Results show that about 16 342 km 2 (c. 1.3% of the total study area) of cropland waterway buffers in the EGP are potentially suitable for switchgrass development. The total annual estimated switchgrass biomass production for these suitable areas is approximately 15 million metric tons. Results from this study provide useful information on EGP areas with good cellulosic switchgrass biomass production potential and synergistic substantial potential for improvement of ecosystem services.

Decreased land use intensity improves surface soil quality on marginal lands

“…Perennial bioenergy grasses such as switchgrass (Panicum virgatum L.) have received great attention because of their adaptability and suitability to marginal lands (Lee et al, 2018). When planted in environmentally susceptible areas across the landscape, these grasses can serve as an erosion buffer to intercept surface runoff and reduce nutrient and sediment loads entering waterbodies (Agostini et al, 2021;Gu & Wylie, 2018;Kreig et al, 2019). Furthermore, perennial grasses can decrease soil bulk density (BD) compared with annual crop because of their extensive and often deep rooting systems and reduced soil compaction due to the absence of tillage and wheel traffic associated with multiple machine passes needed for row-crop production (Karlen et al, 1999).…”

Carbon-Negative Biofuel Production

“…Switchgrass has long been used in riparian buffers. − Riparian buffers are strips of grasses, shrubs, or trees grown along rivers, streams, lakes, and wetlands and provide the following ecosystem services: slowing and absorbing floodwater, trapping and redistributing sediments, cycling nutrients, filtering chemical pollutants, maintaining fish and wildlife habitats, and supporting the food web for biota . The potential of switchgrass grown in riparian areas as feedstock for biofuel production has been studied. ,, Ha and Wu show that the conversion of low-productivity land in watershed land areas to switchgrass production for biofuel can effectively improve water quality by reducing suspended sediment and nutrient runoff.…”

“…17 The potential of switchgrass grown in riparian areas as feedstock for biofuel production has been studied. 15,18,19 Ha and Wu 15 show that the conversion of low-productivity land in watershed land areas to switchgrass production for biofuel can effectively improve water quality by reducing suspended sediment and nutrient runoff.…”