Modeling soil organic carbon dynamics and their driving factors in the main global cereal cropping systems

Abstract

Abstract. Changes in the soil organic carbon (SOC) stock are determined by the balance between the carbon input from organic materials and the output from the decomposition of soil C. The fate of SOC in cropland soils plays a significant role in both sustainable agricultural production and climate change mitigation. The spatiotemporal changes of soil organic carbon in croplands in response to different carbon (C) input management and environmental conditions across the main global cereal systems were studied using a modeling approach. We also identified the key variables that drive SOC changes at a high spatial resolution (0.1 • × 0.1 • ) and over a long timescale (54 years from 1961 to 2014). A widely used soil C turnover model (RothC) and state-of-the-art databases of soil and climate variables were used in the present study. The model simulations suggested that, on a global average, the cropland SOC density increased at annual rates of 0.22, 0.45 and 0.69 Mg C ha −1 yr −1 under crop residue retention rates of 30, 60 and 90 %, respectively. Increasing the quantity of C input could enhance soil C sequestration or reduce the rate of soil C loss, depending largely on the local soil and climate conditions. Spatially, under a specific crop residue retention rate, relatively higher soil C sinks were found across the central parts of the USA, western Europe, and the northern regions of China. Relatively smaller soil C sinks occurred in the high-latitude regions of both the Northern and Southern hemispheres, and SOC decreased across the equatorial zones of Asia, Africa and America. We found that SOC change was significantly influenced by the crop residue retention rate (linearly positive) and the edaphic variable of initial SOC content (linearly negative). Temperature had weak negative effects, and precipitation had significantly negative impacts on SOC changes. The results can help guide carbon input management practices to effectively mitigate climate change through soil C sequestration in croplands on a global scale.

Modelling spatial and temporal soil organic carbon dynamics under climate and land management change scenarios, northern Ethiopia

“…The clay content of the soil is one of the input parameters and is used to calculate how the topsoil can hold available water for plants, and affects organic matter decomposition. The soil moisture, temperature and plant cover affect the SOC decomposition rate (Wang et al, 2017), whereas the clay content of the soil determines the proportion of carbon allocated to CO 2 or to BIO and HUM that undergoes further decomposition to produce CO 2 , BIO and HUM (Yokozawa et al, 2010). The RothC model uses internal algorithms and runs to initialize the C pools (Wang et al, 2016).…”

“…Therefore, there is evidence of carbon saturation in the long run being a potential limit to carbon accumulation in soils' saturation capacity (Hassink, 1997; Stewart, Plante, Paustian, Conant, & Six, 2008). The existing SOC stock changes could be due to climatic change, together with improper land management, such as taking all crop residues for the purpose of animal feed and fuel, stubble grazing of cultivated lands after crop harvest and frequent tillage (Wang, Zhang, Sun, Li, & Han, 2017). This SOC is important for the improvement of soil aggregate stabilities, improvement of infiltration and retention of soil water (Jones et al, 2005).…”

“…This SOC is important for the improvement of soil aggregate stabilities, improvement of infiltration and retention of soil water (Jones et al, 2005). Moreover, SOC is essential to improve crop productivity because it is a nutrient reservoir; it recycles nutrients and sequesters greenhouse gases (Wang et al, 2017). The crop residue retained in the system after harvest benefits the sequestration of soil carbon in croplands (Wang, Luo, Han, Chen, & Xu, 2016).…”

Potencial de secuestro de carbono orgánico en quinua simulado con el modelo RothC-26.3

“…Similarmente a lo encontrado por Wang et al (2017) quienes, a nivel global en cereales con diferentes entradas de C al suelo, tuvieron una correlación alta con los cambios del COS. Particularmente, las tasas de cambio de COS encontradas en quinua de nuestro trabajo respondieron a las condiciones particulares de la productividad de la materia seca influenciada por el clima y retención de residuos, aplicación de abonos y las salidas de MST, como reporta Smith et al (2008); Luo et al (2010) en los sistemas agrícolas. Las ejecuciones de escenarios con el RothC detectaron que ambas quinuas responden a las necesidades actuales del uso de cultivos con potencial de secuestro de COS y para mantener el suelo en una condición de equilibrio entre las ganancias y pérdidas de este elemento (Figura 2).…”

Spatiotemporal changes in cropland soil organic carbon in a rapidly urbanizing area of southeastern China from 1980 to 2015

“…Soil organic carbon (SOC), as a basis of soil fertility, not only affects soil quality and crop production (Jiang et al, 2014; Vågen & Winowiecki, 2013; Zhao et al, 2018), but also plays an important role in the global carbon cycle (Borrelli et al, 2018; Wei et al, 2011). Cropland SOC pool accounts for approximately 10% of the global SOC pool, and the change in cropland SOC is highly sensitive to both natural factors and anthropogenic activities (Fujisaki et al, 2018; Wang et al, 2017). A slight change in cropland SOC may have a profound influence on soil nutrient availability, soil carbon storage, and the atmospheric carbon dioxide concentration (CO 2 ) (Atwood et al, 2017; Keesstra et al, 2018; Li et al, 2021; Luo et al, 2019).…”