Carbon Sequestration in Restored Soils by Applying Organic Amendments

Abstract

The study of different natural carbon sinks has become especially important because of climate change effects. The restoration of contaminated areas can be an ideal strategy for carbon sequestration. The studied area was affected by toxic Aznalcóllar mine spill in 1998. Restoration process of the contaminated area was based, mainly, on the use of two organic amendments: leonardite (LE) and biosolid compost (BC). The objective of this study was to verify whether the application of these amendments promotes the long-term carbon sequestration in this soil. Five treatments were established: untreated control, biosolid compost (doses 4 and 2) and leonardite (doses 4 and 2). The addition of amendments implied an improvement in soil quality that was directly related to the amendment dose: decrease in bulk density, increase in pH, higher respiration rates and an improvement in the stratification ratio. Dose-dependent changes in the molecular composition of soil organic matter were shown by nuclear magnetic resonance analysis. Both amendments promoted carbon retention, although because of the low mineralization rates of soil organic matter in LE treatments, the carbon storage was higher. The dosage effect on the carbon balance was more important in LE treatments, whereas in the BC treatments, the balance was similar for both doses. Our findings suggest that LE4 significantly increased the total organic carbon and it was the most suitable treatment for long-term carbon storage, because of its molecular composition rich in relatively stable aromatic and lignin-derived compounds.

Impact of biochar properties on soil conditions and agricultural sustainability: A review

“…Organic carbon is an important resource which is required to be managed and sustained in the soil for an efficient ecosystem functioning, and different SOC fractions depend on the agro‐technical managements (del Mar Montiel‐Rozas, Panettieri, Madejón, & Madejón, ; Hassan et al, ; Lal, ). Because of its high C content, a primary purpose of applying biochar to soil is to increase SOC levels.…”

The Influence of Organic Carbon and pH on Heavy Metals, Potassium, and Magnesium Levels in Lithuanian Podzols

“…In recent years, derivatives of organic carbon such as composts (Srinivasarao et al, 2014b;Mahmoud & El-Kader, 2015;Montiel-Rozas et al, 2016) and biochar have been considered to be a productive solution to various environmental problems, including soil that has been contaminated with potentially toxic elements (Sohi, 2012;Paz-Ferreiro et al, 2014). Biochar is a high-carbon and fine-grained residue which is produced from organic carbon under thermal decomposition in the absence of oxygen (Lehmann, 2009;Gronwald et al, 2015).…”

Effects of farmed managements in sandy soils on composition and stabilization of soil humic substances

“…The formation of high-molecular-weight HA in soils, predominantly those with more aromatic, recalcitrant, and hydrophobic structures, has been reported to increase aggregate stability, decrease disaggregation effects, and increase microbial growth and CEC (Chaney & Swift, 1986;Piccolo & Mbagwu, 1997;Piccolo & Mbagwu, 1999;Piccolo & Stevenson, 1982;Tan, 2014). The application of exogenous sources of HS, including lignin, to the soil leads to both C accumulation and increased soil fertility (Montiel-Rozas, Panettieri, Madejón, & Madejón, 2015), and there is evidence of increased CEC, water retention capacity and soil aggregation and decreased soil density and resistance to penetration (Aksakal, Sari, & Angin, 2016;Lal, 2006 where the increase in structural recalcitrance could contribute to increased stabilization of humified OM. Conversely, in the case of less intense management systems, including G and AFS, increased HA lability requires enhanced transformation processes such as humification and interaction with the mineral fraction, which also contribute to OM stabilization as previously discussed.…”