Sustainability Protocols and Certification Criteria for Switchgrass-Based Bioenergy

Abstract

Production of bioenergy from cellulosic sources is likely to increase due to mandates, tax incentives, and subsidies. However, unchecked growth in the bioenergy industry has the potential to adversely influence land use, biodiversity, greenhouse gas (GHG) emissions, and water resources. It may have unintended environmental and socioeconomic consequences. Against this backdrop, it is important to develop standards and protocols that ensure sustainable bioenergy production, promote the benefits of biofuels, and avoid or minimize potential adverse outcomes. This paper highlights agronomic information on switchgrass, a high-potential bioenergy feedstock, and the role of specialized certification programs. The existing sustainability standards and protocols were reviewed in order to identify key gaps that justify a certification program specifically for switchgrass-based bioenergy. The criteria and indicators that should be considered for such a certification program are outlined.

Sustainability Indicators for Biobased Product Manufacturing: A Systematic Review

“…In examining the start of any supply chain from farm, forest, or fossil fuel, the effect on the land that provides the resources plays a significant role. Some indicators in papers reviewed from the biomass discipline mentioned documenting land use change and associated GHG emissions, carbon sequestration potential, and GHG release intensity (GHG emissions released during production plus other overheads, divided by a normalization factor) (Baumert et al, 2005;Burli et al, 2016;Heslouin et al, 2017;Huang & Badurdeen, 2017;Kim et al, 2012;Mikko et al, 2013;OECD, 2017bOECD, , 2017cVaidya & Mayer, 2016). Accounting, sales, and marketing aspects (discussed in Section 3.6) are additional factors influencing emissions during product manufacturing (Diamantopoulou et al, 2016;Eseoglu et al, 2014;Heslouin et al, 2017).…”

“…In the reviewed papers, several mentioned quantifying nutrient content (Diamantopoulou et al, 2016;McBride et al, 2011;Oliveira et al, 2013;Thevathasan et al, 2014). They also looked into other soil health issues, including standing tree biomass; soil organic carbon; pH; dehydrogenase activity (the total range of oxidative activity of soil microflora) (Järvan et al, 2014;Wolińska & Stępniewska, 2012), expressed in units of μg TTC/g h, based on the triphenyltetrazolium chloride method (Lin et al, 2017); fluorescein diacetate (FDA) hydrolysis (μg FDA/g h), a measure of enzyme activity; and bulk density (g/cm 3 ) (Burli et al, 2016;Diamantopoulou et al, 2016;Diaz-Balteiro et al, 2017;Fortună et al, 2012;Gaitan-Cremaschi et al, 2015;Haverkort et al, 2009;Kudoh et al, 2015;McBride et al, 2011;Oliveira et al, 2013;Rasmussen et al, 2017;Smith et al, 2017;Vaidya & Mayer, 2016). The papers also track soil balance to estimate total nutrients as import minus export, nitrogen mineralization, and rate and estimation of carbon release and sequestration (CO 2 -C/g) (Oliveira et al, 2013;Rasmussen et al, 2017;Smith et al, 2017).…”

“…This category is linked not only to land, but also labor, capital, and soil properties. Specifically, influences such as land use change, area of cultivation, and soil quality (e.g., colloidal properties of humic substances and color) determine the yield of a given crop in any given year (Burli et al, 2016;Diamantopoulou et al, 2016;Fortună et al, 2012;Gaitan-Cremaschi et al, 2015;Haverkort et al, 2009;Karvonen et al, 2017;Kudoh et al, 2015;Lal et al, 2011;Rasmussen et al, 2017;Vaidya & Mayer, 2016;Valdez-Vazquez et al, 2017). For a more intricate perspective, the concept of multiple factor productivity can be considered, which looks into an array of indexes in relation to both input and output values (Council, 2012;Rehman, 2014).…”

“…The yields of biomass feedstock are influenced by factors such as slope of land, reforestation area, soil degradation, soil quality, type, variety of crop, and nutrient input. Land cover-related units that contribute to stability and resilience, patterns such as mono or intercropping systems, can also be recorded (Burli et al, 2016;Fortună et al, 2012;Oliveira et al, 2013;Rasmussen et al, 2017). Other indirect factors include landscape structure, number of vehicles entering and exiting the area, efficiency of resource use, and the capacity of the environment to meet social and ecological requirements (Gaitan-Cremaschi et al, 2015;Lal et al, 2011;Vaidya & Mayer, 2016;Vinodh & Girubha, 2012).…”

“…Keeping in mind these interlinkages, it is crucial to keep indicators easy to estimate and understand. Therefore, the indicator yield (amount of crop per unit area harvested) expressed in kg product/ha, was identified for productivity (Burli et al, 2016;Diamantopoulou et al, 2016;Diaz-Balteiro et al, 2017;Fortună et al, 2012;Gaitan-Cremaschi et al, 2015;Haverkort et al, 2009;Karvonen et al, 2017;Kudoh et al, 2015;Lal et al, 2011;Oliveira et al, 2013;Rasmussen et al, 2017;Smith et al, 2017;Vaidya & Mayer, 2016;Valdez-Vazquez et al, 2017;Vinodh & Girubha, 2012).…”