Modelling Soil Organic Carbon Changes Under Different Maize Cropping Scenarios for Cellulosic Ethanol in Europe

Abstract

The utilization of crop residues in the production of second-generation biofuels has the potential to boost the bioenergy sector without affecting food commodity prices. However, policies leading to large-scale biomass removal should carefully balance the consequences, both environmental and in terms of emissions, on soil organic carbon (SOC) stocks depletion. Using a recently developed simulation platform, SOC changes were estimated at European level (EU + candidate and potential candidate countries) under two scenarios of low (R30) and high (R90) maize stover removal for cellulosic ethanol production (i.e. 30 and 90 % of stover removal, respectively). Additionally, mitigation practices for SOC preservation, namely the introduction of a ryegrass cover crop (R90_C) and biodigestate return to soil (R90_B), were explored under the highest rate of stover removal. The results showed that 15.3 to 50.6 Mt year −1 of stover (dry matter) would be potentially available for ethanol production under the lower and high removal rates considered. However, largescale exploitation of maize residues will lead to a SOC depletion corresponding to 39.7-135.4 Mt CO 2 eq. by 2020 (under R30 and R90, respectively) with greater losses in the long term. In particular, every tonne of C residue converted to bioethanol was predicted to have an additional impact on SOC loss almost ranging from 0.2 to 0.5 CO 2 eq. ha −1 year −1 , considering a continuous biofuel scenario by 2050. The mitigation practices evaluated could more than halve SOC losses compared to R90, but not totally offsetting the negative soil C balance. There is a pressing need to design policies at EU level for optimum maize biofuel cultivations that will preserve the current SOC stock or even generate C credits.

Production, carbon and nitrogen in stover fractions of corn ( Zea mays L.) in response to cultivar development

“…To preserve soil quality and system productivity, quantitative and qualitative attributes of stover along with other information (e.g. soil type, soil management system, climate) is required to carefully establish proper harvest levels (Blanco-Canqui, 2013;Lugato;Jones, 2015). It is worth noting that since hybrids are the cultivars most widely used in grain production systems (Cruz;Pereira, 2008), the removal and use of their stover is more likely.…”

“…The adoption of cropping systems with no soil tillage has been effective in increasing SOM levels due to a reduction in the loss of C by not turning over the soil (Kumar et al, 2012;Corbeels et al, 2016). In this sense, the intensification of crop rotations using crops with high stover addition (e.g., corn) contributes to positive soil C balance (Govaerts et al, 2009;Lugato;Jones, 2015).…”

Soil application of high-lignin fermentation byproduct to increase the sustainability of liquid biofuel production from crop residues

“…Other studies considers valueadded coproducts derived from HLFB (Schutyser et al 2018, Liu et al 2019. Return of HLFB to the soil has been considered at a conceptual level (Johnson et al 2004, 2007, Johnson 2019 and in a few simulation studies (Pourhashem et al 2013, Adler et al 2015, Lugato and Jones 2015, but lab data are too scant to be conclusive and to our knowledge field studies examining HLFB return have not been reported.…”

Impacts of corn stover removal on carbon dioxide and nitrous oxide emissions

“…Stover removal can also reduce returns of organic matter and plant nutrients to the soil. In a simulation study, Lugato and Jones (2015) estimated that for every metric tonne (Mg) of crop residue that is removed from fields in Europe, the soil organic carbon (SOC) losses would be between 0.2 and 0.5 Mg CO 2 eq ha −1 yr −1 . However, only a few studies have examined the overall effect of this practice on soil biological communities (Lehman et al, 2014;Urra, Mijangos, Lanzén, Lloveras, & Garbisu, 2018), with no studies in the humid regions of eastern Canada.…”