Crop residue harvest for bioenergy production and its implications on soil functioning and plant growth: A review

Abstract

ABSTRACT:The use of crop residues as a bioenergy feedstock is considered a potential strategy to mitigate greenhouse gas (GHG) emissions. However, indiscriminate harvesting of crop residues can induce deleterious effects on soil functioning, plant growth and other ecosystem services. Here, we have summarized the information available in the literature to identify and discuss the main trade-offs and synergisms involved in crop residue management for bioenergy production. The data consistently showed that crop residue harvest and the consequent lower input of organic matter into the soil led to C storage depletions over time, reducing cycling, supply and availability of soil nutrients, directly affecting the soil biota. Although the biota regulates key functions in the soil, crop residue can also cause proliferation of some important agricultural pests. In addition, crop residues act as physical barriers that protect the soil against raindrop impact and temperature variations. Therefore, intensive crop residue harvest can cause soil structure degradation, leading to soil compaction and increased risks of erosion. With regard to GHG emissions, there is no consensus about the potential impact of management of crop residue harvest. In general, residue harvest decreases CO 2 and N 2 O emissions from the decomposition process, but it has no significant effect on CH 4 emissions. Plant growth responses to soil and microclimate changes due to crop residue harvest are site and crop specific. Adoption of the best management practices can mitigate the adverse impacts of crop residue harvest. Longterm experiments within strategic production regions are essential to understand and monitor the impact of integrated agricultural systems and propose customized solutions for sustainable crop residue management in each region or landscape. Furthermore, private and public investments/cooperations are necessary for a better understanding of the potential environmental, economic and social implications of crop residue use for bioenergy production.

Improving phosphorus sustainability of sugarcane production in Brazil

“…Straw : Each kilogram of sugarcane straw on average contains 1.05 g P (Cherubin et al, ; Fortes, Trivelin, & Vitti, ). We consider straw as top leaves + bottom leaves.…”

Sugarcane Straw Blanket Management Effects on Plant Growth, Development, and Yield in Southeastern Brazil

“…In general, both treatments that retained straw (i.e., straw cover, raked) enhanced N and P concentrations in the plant tissue both early and late in the second ratoon. Increased plant nutrient concentrations may reflect the benefits of retaining straw, such as enhanced nutrient cycling (Sousa Jr. et al, 2018) and/or increased C accumulation (Galdos et al, 2017;Cherubin et al, 2018;Sousa Jr. et al, 2018), water storage and infiltration (Valim et al, 2016;Anjos et al, 2017), and biological activity (Paredes Jr. et al, 2015). Healthy soils generally have increased availability of N and P for plant uptake, which subsequently increases plant tissue concentrations of these elements when straw is retained.…”

“…Retaining a portion of sugarcane straw in the field is necessary for protecting several soil functions and to maintain or enhance soil quality (Carvalho et al, 2017; Cherubin et al, 2018). Residue retained on the soil surface creates a microenvironment that affects heat, water, and gas exchange between the soil and atmosphere (Cherubin et al, 2018).…”

Sustainable intensification of crop residue exploitation for bioenergy: Opportunities and challenges

“…However, residue exploitation for bioenergy is subject to several barri ers such as environmental concerns and market, logistic and biomass conversion challenges (IEA Bioenergy, 2017). One of the most acknowledged limitations to large-scale crop res idue exploitation is its likely impacts on long-term soil func tioning, productivity and associated ecosystem services due to reduction of the soil organic carbon (SOC) pool (Carvalho, Hudiburg, Franco, & DeLucia, 2017;Cherubin et al, 2018;Lal, 2005).…”