Enhanced Soil Carbon Storage under Agroforestry and Afforestation in Subtropical China

Abstract

Soil carbon (C) in three Ginkgo (Ginkgo biloba L.) agroforestry systems, afforestation (Ginkgo alone; G), and an agricultural cropping system were compared over a five-year period. The agroforestry systems were Ginkgo + Wheat (Triticum aestivum L.) + Peanut (Arachis hypogaea L.; GWP); Ginkgo + Mulberry (Morus alba L.; GM); and Ginkgo + Rapa (Brassica napus L.) + Peanut (GRP). The agricultural system consisted of wheat and peanut (WP). Total soil carbon (TSC), soil organic (SOC) and inorganic carbon (SIC), and the pools of five SOC chemical fractions were measured. TSC and SOC were always lower under WP than the G-based planting systems, and TSC in the latter increased significantly across years in the top 20 cm. Stocks of SIC under WP were significantly greater than the G-based systems, whereas SOC fractions tended to be lower. Most fractions increased across years but not in WP.

Revisiting IPCC Tier 1 coefficients for soil organic and biomass carbon storage in agroforestry systems

“…The loss of SOC following a LUC can be very quick while it usually takes much longer to gain SOC (Smith 2004), especially with low tree densities. The studies using a diachronic approach to quantify SOC changes in agroforestry are rare (Beer et al 1990, Mazzarino et al 1993, Maikhuri et al 2000, Oelbermann et al 2004, Sierra and Nygren 2005, Swamy and Puri 2005, Raddad et al 2006, Lenka et al 2012, Singh and Gill 2014, Wang et al 2015, most of them have been performed using a synchronic or chronosequence approach. The diachronic approach has been recognized to be a more accurate method to assess SOC changes than other methods (Costa Junior et al 2013).…”

Storage, patterns and influencing factors for soil organic carbon in coastal wetlands of China

“…The stabilization mechanisms of SOC have been intensively discussed with respect to (i) physical protection by aggregates associated with minerals, (ii) the nature of recalcitrant compounds of SOC, and (iii) refractory biological components (such as microbial residual carbon), and cementation of physicochemical function and biological substances (Cui et al, 2014;Sarker et al, 2018;Throckmorton et al, 2015). These SOC stabilization mechanisms have been demonstrated in uplands to increase C sequestration (Fujisaki et al, 2018;Luo et al, 2017;Poeplau et al, 2017;Sarker et al, 2018;Wang et al, 2015). Less attention, however, has been paid to understanding the mechanisms of soil C stabilization in coastal wetlands at large regional scale, and investigations on the relative influence of individual soil properties remain scarce.…”

Enrichment Planting and Soil Amendments Enhance Carbon Sequestration and Reduce Greenhouse Gas Emissions in Agroforestry Systems: A Review

“…In the humid tropics, agroforestry mitigated N 2 O and CO 2 emissions from soils, and increased CH 4 uptake, compared to sole cropping systems [28]. While N 2 O emission in the agroforestry system was as low as 3%, CO 2 emissions were 70% of the high input cropping systems, and CH 4 uptake was almost double that of the low input cropping system [33]. In contrast, management practices that disturbed soil and vegetation, such as tillage, burning of biomass, fertilization, and manuring, lead to net emissions of GHGs from soils and vegetation to the atmosphere [43].…”