Nitrogen Dynamics

Manure Nutrient Dynamics

Nutrients in manure are potentially valuable resources for the management of soil fertility, but these nutrients are potential pollutants as well. Only 10 to 40 percent of the nutrients consumed by animals may end up in the marketed product; the rest is excreted in feces and urine. Manure contains all nutrients needed by plants, but nitrogen and phosphate generally have the most agronomic significance in Nebraska. They are also potential contaminants of water resources. This module focuses on nitrogen.

Manure nutrient dynamics can be considered in three stages:

  • Manure nutrients are produced in feces, urine and other agricultural byproducts associated with an animal feeding operation. The quantity of nutrients produced varies with livestock type as well as the animal ration.
  • Manure nutrients are lost during manure handling, storage, treatment, and application.
  • Manure nutrients become available in the soil for crop uptake or are lost as potential pollutants.
Generalized nitrogen cycle within water, soil and in the air.
Generalized nitrogen cycle within water, soil and in the air.
The Nitrogen Cycle

All nitrogen in or added to the soil is subject to the processes of the nitrogen cycle (figure at right). Some processes are beneficial to plant nutrition while others provide no benefit or are detrimental to plant growth. For example, nitrogen can be converted from forms that are not available to plants, to available forms (and vice versa) by soil bacteria. Nitrogen can be moved by leaching out of the reach of plant roots or can escape into the atmosphere through gaseous loss known as denitrification. Understanding the basic nitrogen cycle provides insight into plant nutrient relationships and can provide the basis of nutrient management decisions on how much and when to apply supplemental nitrogen.

Part I of Nitrogen Dynamics | Part II - Manure Nutrient Losses | Complete the Quiz

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