Crop N Guidelines: Soil N

The nitrogen mineralized from soil organic matter is a major N credit that should be considered when making a plan for fertilizing corn. Soil N is the average amount of N that becomes plant available from soil organic matter every year. The availability of the soil N depends on a couple major factors.

• Soil type: soils vary in texture, drainage, native fertility, organic matter, structure, temperature, etc. Thinking back to the N cycle, these are all factors that influence N mineralization.
• Artificial drainage (drained or undrained): poor drainage limits N mineralization and nitrification. The presence or lack of artificial drainage (e.g. tile drainage) in a field may shift the availablity of N from soil, depending on the native drainage of the soil.

The table, below, contains examples of soil N availability for a range of soils in the Cornell database. Move your mouse over each of the soil names for a description of each soil. Why does the amount of N available from soil organic matter vary across the soil types in the table?

To read more on this subject: Nitrogen Guidelines for Field Crops in New York (section 3.1).