Role of soil moisture management and carbon sequestration in agriculture on mitigating greenhouse gas emissions

Climate change, defined as long-term alterations in weather and temperature patterns, poses a significant threat to life on Earth. These variations may result from natural processes or human activities (Hardy, 2003). A major driver of climate change today is the greenhouse effect, caused by greenhouse gases emitted primarily from fossil fuel combustion, deforestation, and the depletion of soil carbon (C) storage. Among these gases, carbon dioxide (CO₂), methane (CH₄), nitrogen oxides (NOₓ), and fluorinated gases, including hydrofluorocarbons (HCFs), perfluorocarbons (PFCs), and chlorofluorocarbons (CFCs), contribute significantly to global warming with CO₂ being the most abundant (Lehmann et al., 2006). In 2022, agriculture accounted for 11% of total U.S. greenhouse gas emissions with half of those emissions linked to soil and crop management practices (USEPA, 2025).

Role of carbon sequestration on greenhouse gas emissions

Soil is the largest terrestrial C reservoir, storing approximately 2,500 PgC in the top meter of soil while vegetation holds an additional 620 PgC. Together, these two carbon pools store nearly three times the 880 PgC present in the atmosphere (Lal et al., 2021). As a result, soil plays a crucial role in mitigating greenhouse gas emissions by reducing atmospheric CO₂ levels (Lal et al., 2007).

Carbon sequestration, the process of capturing and storing atmospheric CO₂ in the soil, helps minimize net CO₂ emissions from agriculture. It retains carbon either in solid form as organic matter or in dissolved form in soil solution, thereby reducing its gaseous presence in the atmosphere and mitigating the greenhouse effect (Cheddadi et al., 2001; Lal et al., 2021). In addition to lowering atmospheric CO₂, carbon sequestration enhances soil moisture retention, improves soil fertility, and boosts overall soil health and agricultural productivity (Hao et al., 2025).

Soil management practices significantly influence carbon sequestration potential. While some practices enhance soil C storage, others degrade it. Sustainable approaches such as cover cropping, no-till or minimum tillage, and organic farming increase carbon sequestration, whereas conventional tillage, deforestation, and overgrazing diminish it (Smith & Conen, 2006; Zerssa et al., 2021). Additionally, environmental factors such as temperature and soil moisture play key roles in regulating soil carbon dynamics. Since soil organic matter decomposition depends on microbial activity, cooler temperatures slow decomposition and increase soil C storage, whereas warmer temperatures accelerate decomposition and decrease C retention (Lal et al., 2015).

Role of soil moisture in greenhouse gas emissions

Soil moisture indirectly affects greenhouse gas emissions by influencing plant growth, microbial activity, and organic matter decomposition. These processes directly impact atmospheric C fixation, soil carbon sequestration, and greenhouse gas fluxes (Hao et al., 2025). Limited soil moisture impairs photosynthesis, reducing CO₂ fixation and decreasing organic matter inputs to the soil. Consequently, soil microbial communities are affected, slowing organic matter decomposition. Approximately 90% of the variability in global soil C uptake is attributed to soil moisture fluctuations (Humphrey et al., 2021).

Soil respiration, the release of CO₂ from the soil, consists of two components: autotrophic respiration (from plant roots) and heterotrophic respiration (from microbial decomposition). Soil moisture affects both processes at different levels (Hu et al., 2018). Drought conditions, for example, have been shown to reduce autotrophic respiration by 50% in subtropical forests and by 47% in grasslands (Huang et al., 2018; Balogh et al., 2016).

However, extreme moisture conditions—both excessive dryness and excessive wetness—reduce heterotrophic respiration. This process follows a "peak and decline" pattern where heterotrophic respiration increases with soil moisture up to an optimal threshold (~80% water-filled porosity, WFP) but declines beyond this point due to anaerobic conditions (Widanagamage et al., 2025). Under excessive moisture (>80% WFP), oxygen depletion promotes anaerobic microbial respiration, leading to methane production (methanogenesis). Agricultural practices such as flood irrigation, furrow irrigation, and ponding water can increase anaerobic conditions, thereby enhancing methane emissions. Thus, sustainable soil moisture management is critical for minimizing greenhouse gas emissions and maximizing soil C sequestration. Soil texture and structure also influence C sequestration by regulating soil moisture and protecting organic matter within soil aggregates (Blanco-Canqui & Lal, 2004). Tillage and soil compaction caused by agricultural machinery can disrupt soil aggregates, exposing previously stabilized organic carbon and increasing greenhouse gas emissions.

Soil management practices to minimize greenhouse gas emissions

Sustainable soil management practices, including minimum tillage, conservation agriculture, mulching, and cover cropping, play a vital role in promoting carbon sequestration and reducing greenhouse gas emissions (Follet, 2001). Minimum tillage minimizes soil disturbance while no-till farming preserves soil structure and enhances aggregate formation, thereby improving carbon storage capacity and soil hydrological properties (Lal & Kimble, 1997). Conservation agriculture and mulching increase organic matter content, protect soil aggregates, reduce erosion, and enhance soil moisture retention. Similarly, cover cropping ensures continuous vegetation cover, preventing soil erosion, enriching organic matter, stabilizing soil aggregates, and improving overall soil health and carbon storage (Kaye & Quemada, 2017).

Sustainable irrigation practices are essential for lowering agriculture-related greenhouse gas emissions

Sustainable irrigation practices are also essential for lowering agriculture-related greenhouse gas emissions. For example, in rice production, prolonged water saturation creates anaerobic conditions that promote methane production, which has 28 times the global warming potential of CO₂ (Hao et al., 2025). Additionally, some irrigation practices increase nitrous oxide (N₂O) emissions due to excessive soil moisture.

Excessive nitrogen fertilizer application further exacerbates N₂O emissions, a greenhouse gas with 298 times the global warming potential of CO₂. Moreover, land-use practices such as tillage and deforestation, accelerate CO₂ emissions while soil and crop management techniques that enhance nitrogen availability inadvertently increase N₂O emissions.

Conclusion 

Climate change, driven by both natural processes and human activities, is primarily fueled by greenhouse gas emissions such as CO₂, CH₄, and N₂O. Agriculture plays a significant role in these emissions, particularly through soil and crop management practices. While destructive practices like excessive nitrogen use, tillage, and deforestation contribute to greenhouse gas emissions, the soil being the largest terrestrial carbon sink, has the potential to mitigate climate change through carbon sequestration. Implementing sustainable management strategies such as cover cropping, no-till farming, and organic agriculture enhances carbon storage, whereas poor land management practices reduce sequestration capacity. Additionally, factors like soil moisture, temperature, and structure influence carbon dynamics, making sustainable land management essential for mitigating greenhouse gas emissions and combating climate change effectively.

References

Balogh, J., Papp, M., Pintér, K., Fóti, S., Posta, K., Eugster, W., & Nagy, Z. (2016). Autotrophic component of soil respiration is repressed by drought more than the heterotrophic one in dry grasslands. Biogeosciences, 13(18), 5171–5182.

Blanco-Canqui, H., & Lal, R. (2004). Mechanisms of C sequestration in soil aggregates. Critical Reviews in Plant Sciences, 23(6), 481–504.

Cheddadi, R., Guiot, J., & Jolly, D. (2001). The Mediterranean vegetation: What if the atmospheric CO₂ increased? Landscape Ecology, 16, 667–675.

Follett, R. F. (2001). Soil management concepts and C sequestration in cropland soils. Soil and Tillage Research, 61(1-2), 77–92.

Hardy, J. T. (2003). Climate change: causes, effects, and solutions. John Wiley & Sons.

Hu, S., Li, Y., Chang, S. X., Li, Y., Yang, W., Fu, W., ... & Lin, Z. (2018). Soil autotrophic and heterotrophic respiration respond differently to land-use change and variations in environmental factors. Agricultural and Forest Meteorology, 250, 290–298.

Huang, S., Ye, G., Lin, J., Chen, K., Xu, X., Ruan, H., ... & Chen, H. Y. (2018). Autotrophic and heterotrophic soil respiration responds asymmetrically to drought in a subtropical forest in the Southeast China. Soil Biology and Biochemistry, 123, 242–249.

Humphrey, V., Berg, A., Ciais, P., Gentine, P., Jung, M., Reichstein, M., ... & Frankenberg, C. (2021). Soil moisture–atmosphere feedback dominates land C uptake variability. Nature, 592(7852), 65–69.

Kaye, J. P., & Quemada, M. (2017). Using cover crops to mitigate and adapt to climate change. A review. Agronomy for Sustainable Development, 37, 1–17.

Lal, R., Follett, R.F., Stewart, B.A., & Kimble, J.M. (2007). Soil C sequestration to mitigate climate change and advance food security. Soil Science, 172, 943–956.

Lal, R., Monger, C., Nave, L., & Smith, P. (2021). The role of soil in regulation of

Hao, Y., Mao, J., Bachmann, C. M., Hoffman, F. M., Koren, G., Chen, H., ... & Dai, Y. (2025). Soil moisture controls over C sequestration and greenhouse gas emissions: a review. npj Climate and Atmospheric Science, 8(1), 16.

Lal, R., Negassa, W., & Lorenz, K. (2015). C sequestration in soil. Current Opinion in Environmental Sustainability, 15, 79–86. https://doi.org/10.1016/j.cosust.2015.09.002

climate. Philosophical Transactions of the Royal Society B, 376(1834), 20210084.

Lehmann, J., Gaunt, J., & Rondon, M. (2006). Bio-Char sequestration in terrestrial ecosystems—a review. Mitigation and Adaptation Strategies for Global Change, 11, 403–427.

Smith, K.A., & Conen, F. (2006). Impacts of land management on fluxes of trace greenhouse gases. Soil Use Management, 20, 255–263.

Widanagamage, N., Santos, E., Rice, C. W., & Patrignani, A. (2025). Study of soil heterotrophic respiration as a function of soil moisture under different land covers. Soil Biology and Biochemistry, 200, 109593. https://doi.org/10.1016/j.soilbio.2024.109593

Zerssa, G., Feyssa, D., Kim, D.-G., & Eichler-Löbermann, B. (2021). Challenges of smallholder farming in Ethiopia and opportunities by adopting climate-smart agriculture. Agriculture, 11, 192.