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  Harnessing soil carbon sequestration to address climate change challenges in agriculture

  Elevating levels of atmospheric carbon dioxide (CO2), primarily driven by the burning of fossil fuels, combustion of organic matter, and unsustainable land practices, have amplified global concerns regarding climate change. The industrial revolution has propelled the rise in CO2 emissions, leading to anticipated increases in concentrations and alterations in CO2 sequestration within agricultural soils. Land use alterations, encompassing deforestation, biomass burning, changes in agricultural conditions, drainage of natural wetlands, and incorrect soil management practices, have further amplified these emissions. Moreover, the reduction of soil organic carbon (SOC), an outcome of soil degradation and mismanagement, has intensified atmospheric CO2 levels. However, by implementing state-of-the-art land application and contemporary management systems in agriculture, there's potential to slow the rate of CO2 emissions. The restoration of depleted SOC is possible through various strategies, such as converting marginal lands into restorative uses, promoting reduced or zero-tillage practices combined with cover or residue crops, and implementing nutrient cycling via composting, manure application, and other sustainable soil and water management techniques. Long-term soil carbon sequestration is increasingly being viewed as a comprehensive strategy to combat climate change. By rejuvenating depleted soils, enhancing biomass production, purifying surface and groundwater, and offsetting CO2 emissions from fossil fuels, soil carbon sequestration can serve as a holistic and effective approach for mitigating current climatic changes. Adoption of these innovative techniques is crucial in managing the challenges imposed by recent environmental changes, positioning soil carbon sequestration as a promising solution. This review aims to explore the potential methods of mitigating climate change through the implementation of soil carbon sequestration strategies.
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  The role of soil in regulation of climate

  The soil carbon (C) stock, comprising soil organic C (SOC) and soil inorganic C (SIC) and being the largest reservoir of the terrestrial biosphere, is a critical part of the global C cycle. Soil has been a source of greenhouse gases (GHGs) since the dawn of settled agriculture about 10 millenia ago. Soils of agricultural ecosystems are depleted of their SOC stocks and the magnitude of depletion is greater in those prone to accelerated erosion by water and wind and other degradation processes. Adoption of judicious land use and science-based management practices can lead to re-carbonization of depleted soils and make them a sink for atmospheric C. Soils in humid climates have potential to increase storage of SOC and those in arid and semiarid climates have potential to store both SOC and SIC. Payments to land managers for sequestration of C in soil, based on credible measurement of changes in soil C stocks at farm or landscape levels, are also important for promoting adoption of recommended land use and management practices. In conjunction with a rapid and aggressive reduction in GHG emissions across all sectors of the economy, sequestration of C in soil (and vegetation) can be an important negative emissions method for limiting global warming to 1.5 or 2°C This article is part of the theme issue ‘The role of soils in delivering Nature's Contributions to People’.
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  A Paradigm Shift to CO2 Sequestration to Manage Global Warming – With the Emphasis on Developing Countries

  Global land use changes that tend to satisfy the food needs of augmenting population is provoking agricultural soils to act as a C source rather than sink. Agricultural management practices are crucial to offset the anthropogenic C emission; hence, Carbon sequestration (CS) in agriculture is a viable option for reversing this cycle, but it is based on hypotheses that must be questioned in order to contribute to the development of new agricultural techniques. This review summarizes a global perspective focusing on 5 developing countries (DC) (Bangladesh, Brazil, Argentina, Nigeria and Mexico) because of their importance on global C budget and on the agricultural sector as well as the impact produced by several global practices such as tillage, agroforestry systems, silvopasture, 4p1000 on CO2 sequestration. We also discussed about global policies regarding CS and tools available to measure CS. We found that among all practices agroforestry deemed to be the most promising approach and conversion from pasture to agroforestry will be favorable to both farmers and in changing climate, (e.g., agroforestry systems can generate 725 Euroeq C credit in EU) while some strategies (e.g. no-tillage) supposed to be less promising and over-hyped. In terms of conservative tillage (no-, reduced-, and minimal tillage systems), global and DC’s land use increased. However, the impact of no-tillage is ambiguos since the beneficial impact is only limited to top soil (0-10 cm) as opposed to conventional mechanisms. Grasses, cereals and cover crops have higher potential of CS in their soils. While the 4p1000 initiative appears to be successful in certain areas, further research is needed to validate this possible mode of CS. Furthermore, for effective policy design and implementation to obtain more SOC stock, we strongly emphasize to include farmers globally as they are the one and only sustainable driver, hence, government. and associated authorities should take initiatives (e.g., stimulus incentives, C credits) to form C market and promote C plantings. Otherwise, policy failure may occur. Moreover, to determine the true effect of these activities or regulations on CS, we must concurrently analyze SOC stock adjustments using models or direct measurements. Above all, SOC is the founding block of sustainable agriculture and inextricably linked with food security. Climate-smart managing of agriculture is very crucial for a massive SOC stock globally especially in DC’s.