Why is it that agriculture produces so much nitrogen oxides? Is it just fertilizer, or is there something more

Question

Why is it that agriculture produces so much nitrogen oxides? Is it just fertilizer, or is there something more

Answer 1

Across the midwest, approx 90,000,000 acres are planted to corn each year..To obtain  maximum yields most  producers  apply nitrogen fertilizers..usually more than the plant utilizes..some leaches into ground waters..some erodes with rain or irrigation water runoff.  Wheat farmers also use nitrogen ferilizers, but not as much per acre as corn & sorghum producers.

Answer 2

Yes it is fertilizer

Answer 3

Nitrates are required to produce proteins, and proteins are needed to produce all of our food. So the amount of food plants can produce is distinctly limited by availability of all 16 essential elements, the largest 3 being nitrogen, phosphorus and Potassium (NPK).

We do get concentrations of nitrates when animals, including people, consume the plants and then defecate/urinate.

The total amount of nitrogen fertilizer that a pasuring animal will return to the soil is close to the amount the plants it eats need to grow. A small incremental amount is produced by bacteria on plant roots or blue-green algae.

If the land is not supplying food for people at distance from the land, or for animals living elsewhere, the cycle produces only small amounts to get into the aquifers. What cause big flow into aquifer or stream is concentrated livestock growing in feedlots, or of course cities. CIties do produce massive amountrs of nitrogen fertilizer flows into the rivers that flow out from them. This is because people must have protein,and brfeakdown of protein gives nitrogen fertilizer.

Answer 4

Most pastoral systems are based around establishing a clover driven pasture, so that the clover fixes nitrogen for the pasture as a whole to grow.  This nitrogen is converted (via urease, an enzyme) to amonium, which is then converted to nitrite (by nitrosomonas bacteria), then nitrate.  The plant can take up N in the ammonium and nitrate forms.  If there is more nitrate than can be utilised by the plant, there is the risk of it being lost to the atmosphere or leaching.  It is not only the clover that fixes the nitrogen, but the excreta from animals also contains nitrogen, which results in the production of some nitrogen oxide.  Although nitrogen fertilisers can have an effect, the animal and clover produce a lot more than will ever be applied with fertiliser (a urine patch from a cow applies about 1000kg/ha of nitrogen, compared to "normal" application rates in fertiliser of 20 to 40 kg/ha).

Answer 5

The majority of nitrogen in crops is in protein which is an  ammoniacal form rather than as one of the nitrogen oxides.  Over time the ammonia gradually converts to nitrate under the right conditions.