How are the different sources of N made available to the plant or, on the other hand, lost from the root system to the air or water?
The N Cycle involves many processess that make the N in manure, fertilizer, soil, and killed sod available to plants. Plant available N can also be lost from the rootzone to the atmosphere and groundwater and/or taken up by competing organisms (e.g. weeds, soil microbes, etc.).
The major conversion processes at play in the crop and soil N cycle are below:
Although not conversion processes, the following are key components of the N Cycle:
Step through the interactive N cycle diagram to see how each N source can be converted to other forms of N by the conversion processes, above. What does it mean for crop production (i.e. N uptake by plants)? For losses from the rootzone to water and air?
As you step through the N cycle, answer the questions on the N Cycle Worksheet and bring the worksheet and any questions to class.
For a printable, fact sheet version of the N cycle: N Cycle Fact Sheet.
To read more on this subject: Nitrogen Guidelines for Field Crops in New York (section 2).
Continue on to see how the basics of the N cycle are used to determine crop N requirements.