Soil organic carbon content and composition of 130‐year crop, pasture and forest land‐use managements

Abstract

Conversion of former agricultural land to grassland and forest ecosystems is a suggested option for mitigation of increased atmospheric CO 2 . A Sharpsburg prairie loess soil (fine, smectitic, mesic Typic Argiudoll) provided treatments to study the impact of long-term land use on soil organic carbon (SOC) content and composition for a 130-year-old cropped, pasture and forest comparison. The forest and pasture land use significantly retained more SOC, 46% and 25%, respectively, compared with cropped land use, and forest land use increased soil C content by 29% compared with the pasture. Organic C retained in the soils was a function of the soil N content (r 5 0.98, Po0.001) and the soil carbohydrate (CH) concentration (r 5 0.96, Po0.001). Statistical analyses found that soil aggregation processes increased as organic C content increased in the forest and pasture soils, but not in the cropped soil. SOC was composed of similar percentages of CHs (49%, 42% and 51%), amino acids (22%, 15% and 18%), lipids (2.3%, 2.3% and 2.9%) and unidentified C (21%, 29% and 27%), but differed for phenolic acids (PAs) (5.7%, 11.6% and 1.0%) for the pasture, forest and cropped soils, respectively. The results suggested that the majority of the surface soil C sequestered in the long-term pasture and forest soils was identified as C of plant origin through the use of CH and PA biomarkers, although the increase in amino sugar concentration of microbial origin indicates a greater increase in microbial inputs in the three subsoils. The practice of permanent pastures and afforestation of agricultural land showed long-term potential for potential mitigation of atmospheric CO 2 .

Distribution of Organic Carbon in Different Soil Fractions in Ecosystems of Central Amazonia

“…Other factors that have been classified as immediate causes of a decline in SOC include residue removal, soil erosion, intensive tillage and bare fallowing (Lal and Kimble, 2000). Awiti et al (2008) show that changes in the forest for other uses reduce soil C and N due to changes in biomass and litter input, mainly on the surface (Martens et al, 2003). Other studies confirm the results found here, emphasizing that AFS has the potential for restoring degraded land, maintaining soil fertility and, more recently, sequestering C, mitigating C emissions to the atmosphere (Oelbermann et al, 2004;Mutuo et al, 2005).…”

A global meta‐analysis of soil exchangeable cations, pH, carbon, and nitrogen with afforestation

“…For instance, ;50% of sites in this analysis are Pinus plantations compared to ;45% of the afforested area globally (Table 1; FAO 2001a, b). The majority of the Barton et al (1999) Scotland pine Binkley and Resh (1999) USA eucalyptus Binkley et al (1989) USA pine Burton et al (2007) Australia pine Chen et al (2007) China pine Chen et al (2000) New Zealand pine Condron and Newman (1998) New Zealand other conifer Condron and Newman (1998) New Zealand pine Davis (1994) New Zealand pine Davis (1995) New Zealand pine Davis (2001) New Zealand pine Davis and Lang (1991) New Zealand pine Del Galdo et al (2003) Italy other angiosperm Garbin et al (2006) Brazil pine Garg and Jain (1992) India other angiosperm Giddens et al (1997) New Zealand pine Gilmore and Boggess (1963) USA pine Groenendijk et al (2002) New Zealand pine Guevara-Escobar et al (2002) New Zealand other angiosperm Guo et al (2007) Australia pine Hawke and O'Connor (1993) New Zealand pine Hofstede et al (2002) Ecuador other angiosperm Hofstede et al (2002) Ecuador pine Huygens et al (2005) Chile pine Jain and Singh (1998) India other angiosperm Jobbagy and Jackson (2003) Argentina eucalyptus Jug et al (1999) Germany other angiosperm Lilienfein et al (2000) Brazil pine Lima et al (2006) Brazil eucalyptus Mao et al (1992) China eucalyptus Markewitz et al (1998) USA pine Martens et al (2004) USA other angiosperm Menyailo et al (2002) Russia other angiosperm Menyailo et al (2002) Russia other conifer …”

Where Carbon Goes When Water Flows: Carbon Cycling across the Aquatic Continuum

“…(4) Terrestrial plants fix atmospheric CO 2 through photosynthesis, returning a fraction back to the atmosphere through respiration (Field et al, 1998). Lignin and celluloses represent as much as 80% of the OC in forests and 60% in pastures (Martens et al, 2004;Bose et al, 2009). (5) Litterfall and root OC mix with sedimentary material to form organic soils where plant-derived and petrogenic OC is both stored and transformed by microbial and fungal activity (Schlesinger and Andrews, 2000;Schmidt et al, 2011;Lehmann and Kleber, 2015).…”