Sustainability of soil fertility and the use of lignocellulosic crop harvest residues for the production of biofuels: a literature review

Abstract

Use of lignocellulosic crop harvest residues for liquid or gaseous biofuel production may impact soil quality, long-term soil fertility and the major determinants of the latter, stocks of soil organic carbon and nutrients. When soil organic carbon stocks of mineral cropland soils are to be maintained, there is scope for the removal of lignocellulosic harvest residues in several systems with much reduced tillage or no tillage. The scope for such removal might be increased when suitably treated residues from the conversion of harvest residues into biofuel are returned to cropland soils. For mineral cropland soils under conventional tillage, the scope for the production of liquid biofuels from harvest residues is likely to be less than in the case of no-till systems. When fertility of cropland soils is to be sustainable, nutrients present in suitably treated biofuel production residues have to be returned to these soils. Apparently, the actual return of carbon and nutrients present in residues of biofuel production from crop harvest residues to arable soils currently predominantly concerns the application of digestates of anaerobic digestion. The effects thereof on soil fertility and quality need further clarification. Further clarification about the effects on soil fertility and quality of chars and of co-products of lignocellulosic ethanol production is also needed.

Global Bioeconomy Assessment: Coordinated Efforts of Policy, Innovation, and Sustainability for a Greener Future

“…Such expansion may target "marginal" lands to avoid clashing with food crops, which can detrimentally affect natural ecosystems (Tilman et al 2009;Gelfand et al 2013). Even agricultural and forestry residues may have concealed costs since these residues play vital roles in soil fertility and biodiversity protection (Reijnders 2013;Victorsson and Jonsell 2013). Research worldwide underscores that replacing natural ecosystems with bioenergy crops, especially high-yield ones, can significantly harm biodiversity (Núñez-Regueiro, Siddiqui and Fletcher Jr. 2021).…”

Climate-Neutral Agriculture?

“…Moreover, as the demand for food is expected to increase greatly in the coming decades, the option of energy crops becomes even less attractive [7]. As to the use of lignocellulosic harvest residues for biofuel, it should be noted that there is a case for applying at least a part thereof to the soil to prevent a reduction in soil carbon stocks, serve soil fertility and protect against soil erosion [71,72]. The remainder of the harvest residues may be applied to the production of power and heating (e.g., [7,72,73]).…”

Bioenergy and Biodiversity: Key Lessons from the Pan American Region

“…Likewise, prescriptions for harvesting biomass for bioenergy on ''marginal'' land to avoid direct competition with food crops (Tilman et al 2009;Gelfand et al 2013) tend to encounter economic or ecological difficulties, due to low productivity and socioecological values provided by lands subjectively defined as marginal (Dale et al 2010c;Fahd et al 2012;Bryngelsson and Lindgren 2013;ButterbachBahl and Kiese 2013). Using agricultural or forestry residue (e.g., corn stover, tree slash and stumps; Tilman et al 2009) also comes at a cost when the residues are critical for soil fertility, protecting soils against excessive erosion, and biodiversity conservation (Reijnders 2013;Victorsson and Jonsell 2013).…”