Spatiotemporal Variability of Soil Organic Carbon Content Over India Based on an Ecosystem Model and Regional Databases

Biogenic link to the recent increase in atmospheric methane over India

“…The experimental soil belongs to the Vertisol order of U.S. soil Taxonomy and filled in 1300 cm 3 pots, which were planted with two (21 days old) rice plants per pot after taking out from nursery. The crop management and yield estimation were done during crop growth and maturity, respectively (Nayak et al, 2020). The nutrients N, P and K were supplied at a rate of 125, 62.5, and 45 kg ha − 1 of N, P, and K, respectively, as soil test based (STB) recommendation in the form of Urea, Single superphosphate (SSP), and Muriate of potash (MOP) as per the treatment details.…”

“…The emission of methane is strongly influenced by soil bio-geochemistry, which depends on soil pH, soil temperature and SOC. The increase in the organic carbon in croplands in the past decades (Nayak et al, 2020) indicates the increased use of organic fertilizers and soil conditioners. The production of organic manures (r = 0.98) and (Table S2b) the use of chemical fertilizers (r = 0.61) in paddy increases CH 4 emissions (Galic et al, 2020).…”

Soil organic carbon stocks and quality in small-scale tropical, sub-humid and semi-arid watersheds under shrubland and dry deciduous forest in southwestern India

“…2). These stocks were in the same range than modelled SOC stocks of 62-80 Mg ha −1 for the first metre under tropical mixed shrubland/grassland (Nayak et al, 2020). They were lower compared to global estimates for tropical grassland (100.9 Mg ha −1 for 0-100 cm; (Duarte-Guardia et al, 2019)) or tropical grassland/ savannah ecosystems (108-218 Mg ha −1 for 0-300 cm; (Carvalhais et al, 2014)), but for different depth intervals.…”

“…This was depicted in the present study by high replication in small, contrasting watersheds; however, these small-scale watersheds cannot be considered as representative for the whole Western Ghats ecoregion as compared to Dharumarajan et al (2021). If we would extrapolate our SOC stocks for sites (F4 and F6 respectively) where we have measured SOC contents up to 1 m (by approximating the BD for 60-100 cm from the average BD of 45-60 cm), the total SOC stock would account for 174.2 and 159.8 Mg ha −1 respectively (data not shown), which would fall in the range of SOC stocks up to 1 m depth predicted for deciduous forests (125-240 Mg ha −1 ) across India (Nayak et al, 2020). Recent global estimates of SOC stocks in the first metre for tropical dry forests (130.7 ± 40.5 Mg ha −1 ) were also comparable to our findings (Duarte-Guardia et al, 2019).…”