Farming progress can mean climate progress as processing tomato growers are proving in California. Since the tomato growers shifted almost totally to buried drip irrigation, water use  became more efficient,  yields increased, fertilizer was more precisely applied through the drip system, and, surprisingly the emission of one of the most potent green house gases, nitrous oxide, was virtually eliminated.  Of the three primary green house gases, carbon and methane are best known, but nitrous oxide will stay in the atmosphere for 300 years.  Agriculture  produces 7% of all green house gases but 70% of all nitrous oxide comes from agriculture.  To combat climate change green house gas emissions must be assessed, mitigated and reversed where possible.   To explain how progress is being made, Dr. Will Horwath, the Chairman and Professor of Soil Biogeochemistry of the Department of Land air and Waster Resources of UC Davis visits Farm To Table Talk.