New NebGuide - Crop Management to Reduce Soil Nitrous Oxide Emissions in Nebraska

New NebGuide - Crop Management to Reduce Soil Nitrous Oxide Emissions in Nebraska

A new NebGuide, G2322, authored by Bijesh Maharjan, Virginia Jin, Laila Puntel, Javed Iqbal, Tyler Williams, Humberto Blanco and Charles Wortmann, is available in both html and PDF formats.

Nitrous oxide (N2O) is the greenhouse gas most associated with crop production. This NebGuide covers basic information about nitrous oxide. It addresses the following practices for effects on soil N2O emission with considerations of cost-effectiveness.

  1. Avoid excessive irrigation for no-cost reduction of N2O emission.
  2. Reduce fertilizer-N applied and the amount of residual soil nitrate-N
    • Reduce fertilizer-N rates to the most profitable rates for no-cost reduction of N2O emission
    • Apply N at 25 lb/ac below the most profitable rate for very low-cost reduction of N2O emission
    • In-season N application for sandy loam or sandier soil, often for no-cost or low-cost reduction of N2O emission
    • Better crediting of manure-N for no-cost reduction of N2O emission
    • Less corn-corn, often for no-cost reduction of N2O emission, and
    • Alfalfa in rotation, especially in community wellhead protection areas, often for no-cost reduction of N2O emission.
  3. Well-targeted double cropping and cover crops with some costs for reduction of N2O emission
  4. Timely and well-targeted nitrification inhibitor use with some costs for reduction of N2O emission
  5. Corn stover harvest, often for no-cost reduction of N2O emission.
  6. Tillage effects on N2O emission have been inconsistent with inconclusive results.

Most of the practices for reducing soil emission of N2O will also result in reductions of other losses of N to the environment, including reduced leaching of nitrate beyond the depth of crop rooting zones. Much reduction can be achieved with a gain in profit or at no cost while other practices do have some cost.