New Article: Agroforestry systems: Meta‐analysis of soil carbon stocks, sequestration processes, and future potentials
Agroforestry (AF) has the potential to restore degraded lands, provide a broader range of ecosystem goods and services such as carbon (C) sequestration and high biodiversity, and increase soil fertility and ecosystem stability through additional C input from trees, erosion prevention, and microclimate improvement. Advantages and processes for global C sequestration in AF are unknown.
Agroforestry (AF) is an intermediate land use practice that combines trees or shrubs with crops or pastures and thus merges the ecosystem characteristics of forests and cropland or pastures (Figure 1). AF is an integrated approach to sustainable land use because of its socioeconomic advantages and environmental benefits, including prevention of soil erosion and microclimate improvement, as well as higher crop productivity (Nair et al., 2011, Nair, 2013; Torralba, 2016).
AF has also been adopted as a greenhouse gas mitigation strategy under the Kyoto Protocol since 2007 (Baah‐Acheamfour et al., 2017; Stavi & Lal, 2013). The current review has summarized and documented the lower C loss through greenhouse gas emissions in AF systems compared with croplands (Kim, Kirschbaum, & Beedy, 2016). Thus, there is increasing research interest in the C sequestration potential, processes, and mechanisms in AF systems (Nair, Kumar, & Nair, 2009a; Lorenz & Lal, 2014; Zomer et al., 2016).
AF promotes C sequestration relative to cropland or pasture. This review indicated that all four main AF systems—alley cropping, windbreaks, silvopastures, and homegardens—sequestered significantly more C than did cropland (or pasture). Of the four main AF systems, silvopasture sequestrated the most C aboveground, whereas homegardens were best at storing C in soil per area unit. Homegardens, however, currently cover only a small area and thus have great potentials for future C sequestration by increasing the area. Carbon sequestered in AF aboveground is slightly more than in the upper 20‐cm soil but much smaller than C stocks in soil up to 1‐m depth. Read further the open article