I caught part of Forum on KQED on Wednesday morning, and now am listening to it again.
The evidence of overwhelming nitrate pollution of groundwater in the Central Valley and Salinas Valley is in. This is a serious health problem in drinking water. It's a particular problem for people in small rural communities where the cost of remedying the problem is prohibitive.
What amazed me was the extent to which the host kept asking what the high nitrogen water is doing to our food supply. Gosh. I thought it was junior high science that nitrogen is a nutrient necessary to plant growth. Another example of how a lack of basic scientific knowledge contributes to public fears. What century is this anyway?
In spite of this, and the lack of sophistication around agricultural issues, the shocking statistic cited by one of the guests was that 1 million Californians don't have safe drinking water.
Also interesting to learn that use of synthetic fertilizers here has not been increasing for twenty years or so, that most of the Central Valley depends on ground water, not surface water, for drinking, and that the effects of nitrogen contamination are heightened by development for housing of former agricultural tracts.
I just did some web crawling to see what kind of resources are out there on the nitrogen cycle. Turns out there are lots. What fascinated me the most was that each depiction of the nitrogen cycle features an animal to represent the contribution of animal waste to the cycle. Most show a holstein. One shows a bunny. And this one http://www.esa.org/science_resources/issues/FileEnglish/issue1.pdf shows a bear! Reminds me of a certain overworked sarcastic retort.