Improved understanding of changes in soil recalcitrant organic carbon (C) in response to global warming is critical for predicting changes in soil organic C (SOC) storage. Here, we took advantage of a long-term field experiment with increased temperature and precipitation to investigate the effects of warming, increased precipitation and their interactions on SOC fraction in a semiarid Inner Mongolian grassland of northern China since April 2005. We quantified labile SOC, recalcitrant SOC and stable SOC at 0–10 and 10–20 cm depths.

When a chartered fishing boat strewed 100 tonnes of iron sulphate into the ocean off western Canada last July, the goal was to supercharge the marine ecosystem. The iron was meant to fertilize plankton, boost salmon populations and sequester carbon. Whether the ocean responded as hoped is not clear, but the project has touched off an explosion on land, angering scientists, embarrassing a village of indigenous people and enraging opponents of geoengineering.

Phytolith occluded carbon (PhytOC) which is stable in the soil environment is considered to be an important
fraction of soil organic carbon and substantially contributes to the terrestrial carbon sequestration for long periods (millennia). Phytoliths are silica bodies produced by plants as a result of biomineralization process. During this process, occlusion of carbon also takes place within the phytoliths. Some of the major agricultural crops like barley, maize, rice, sorghum, sugarcane and wheat are known to be prolific producers of phytolith and PhytOC. In India, an estimate