Nitrogen good or bad?

Background information

Did you know that all organisms need nitrogen to survive? While the atmosphere is full of nitrogen, it is in a form that can’t be used by living things. Processes within the nitrogen cycle convert nitrogen from the atmosphere into a form that plants and animals can use. Humans alter and influence the nitrogen cycle, primarily through the use of fertilizers, which can have serious environmental consequences.

Impact on cycle of humans

The chief culprit is fossil fuel combustion, which releases nitric oxides into the air that combine with other elements to form smog and acid rain. But it has been difficult to know precisely the extent to which such emissions have altered the nitrogen balance.

Measures to protect nitrogen cycle

  • Never exceed nitrogen-based manure rates [83.293 (a) (1)]. The rate may not exceed the amount of nitrogen necessary to achieve realistic expected crop yields or the amount of nitrogen the crop will utilize for an individual crop year.
  • Time manure and fertilizer applications as close to crop uptake as practical [83.294(a & b)]. Nutrients shall be applied to fields during times and conditions that will hold the nutrients in place for crop growth, and protect surface water and groundwater using best management practices (BMPs) as described in the plan.
  • For fall- and winter-applied manures, cover crops are encouraged to be planted [83.294(f & g)]. For fall applications, manure should only be applied if a cover crop will be planted and grow enough for nutrient uptake, or if the manure is injected (or other no-till incorporation methods) within five days. For winter applications, fields must have at least 25 percent cover by crop residue or an established cover crop.
  • Setbacks and buffers [83.294 (f)]. Manure may not be applied within 100 feet of a stream or intermittent stream bed unless a 35-foot permanent vegetative buffer is established. It may not be applied within 100 feet of an open sinkhole (meaning there is direct access to the water table at the bottom) unless a 35-foot permanent vegetative buffer is established. Manure also cannot be applied within 100 feet of private wells or public drinking water sources.
  • Use the PSNT or chlorophyll meter to determine supplemental nitrogen needs [83.293 (d)]. Recommendations based on these tests may be used in place of supplemental N needs in a nutrient management plan.
  • Incorporate manure as soon after application as practical or use low disturbance manure injection [83.291 (d) and 83.293(f)(5)(i)]. The planned incorporation time is used to determine the amount of N available from manure.
Big image