Fertilizer use responsible for increase in nitrous oxide in atmosphere

[Dead_Parrot]

University of California, Berkeley, chemists have found a smoking gun proving that increased fertilizer use over the past 50 years is responsible for a dramatic rise in atmospheric nitrous oxide, which is a major greenhouse gas contributing to global climate change.

Climate scientists have assumed that the cause of the increased nitrous oxide was nitrogen-based fertilizer, which stimulates microbes in the soil to convert nitrogen to nitrous oxide at a faster rate than normal.

The new study, reported in the April issue of the journal Nature Geoscience, uses nitrogen isotope data to identify the unmistakable fingerprint of fertilizer use in archived air samples from Antarctica and Tasmania.

“Our study is the first to show empirically from the data at hand alone that the nitrogen isotope ratio in the atmosphere and how it has changed over time is a fingerprint of fertilizer use,” said study leader Kristie Boering, a UC Berkeley professor of chemistry and of earth and planetary science.

More: http://newscenter.berkeley.edu/2012/04/02/fertilizer-use-responsible-for-increase-in-nitrous-oxide-in-atmosphere/
Paper (sub): http://www.nature.com/ngeo/journal/v5/n4/full/ngeo1421.html

[drokhole]

1. Artificial fertilizer has absolutely decimated our soil...

...along with the monoculture farming it's largely used in conjunction with. Just watched this today, it's phenomenal:

DIRT! The Movie (TRAILER)

Available in full here:
http://www.hulu.com/watch/191666/dirt-the-movie

[GliderGuider]

2. A tip of the planetary hat...

To Norman Borlaug and the Law of Unintended Consequences.

The road to Hell is paced with good intentions.

[JDPriestly]

3. Would that include compost from garden and food waste?

[NickB79]

4. Probably not. The decomposition time for compost is pretty long

Even a "hot pile" won't churn out finished compost in under 4-5 months, in my experience. A cold pile will take a full year to finish off. It looks like the major problem with synthetic fertilizers is that they offgas so rapidly that the biosphere can't hold onto them and convert them into biomass. For example, right now farmers are pumping anhydrous ammonia into the fields in my backyard. It's a gas that's been pressurized and cooled to function as a semi-liquid at application, but without crops to incorporate the nitrogen it would be gone from the soil in only a few months, tops. I'm sure compost piles offgas some nitrogen, but nothing compared to what artificial fertilizers do.

[FogerRox]

5. AS Nick says no.

Granular fertilizer applications are often many times too much. 2-3 fold over what might really be needed.

Low PH soils may have nitrogen stored in the soil that is unavailable to the plant, liming would release the nitrogen so the plant can take it up. 20-40 yrs ago it was typical to just keep applying nitrogen until the grass turned the dark shade of green desired, but the majority of that nitrogen actual bonded to clay particles in the soil, and never made it to the plant.

See cat ion exchange capacity.