Rattan Lal

• argues that agricultural soil could absorb 13% of atmospheric CO₂

• erosion occurs more readily when soil is 1. 
• found extremely 2.  soil during his research in Africa

• encountered the theory that carbon had moved from soil into the atmosphere

Soil and carbon

• plants convert atmospheric CO₂ into carbon-based materials such as 3. 
• some carbon dioxide products pass from plant 4.  to soil microbes

• the invention of farming caused carbon to disappear from soil

Regenerative agriculture

• applies established methods to keep soil productive and 5. 
• examples include planting throughout the year and growing a wider 6.  of plants

California study

• is being conducted on a large 7.  farm
• applies compost containing agricultural waste and waste from 8. 

Australian study

• attempts to build soil carbon by planting permanently green 9. 

Possible future developments

• using less fertiliser in agriculture

• providing farmers with 10.  for storing carbon as well as producing food