United States Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Accessibility Remediation
If you are unable to use this item in its current form due to accessibility barriers, you may request remediation through our remediation request form.
Document Type
Article
Date of this Version
2002
Citation
Nutrient Cycling in Agroecosystems 63: 251–254, 2002.
Abstract
Inorganic nitrogen in the soil is the source of N for non-legume plants. Rapid methods for monitoring changes in inorganic N concentrations would be helpful for N nutrient management. The effect of varying soil moisture content on soil mineral nitrogen, electrical conductivity (EC), and pH were studied in a laboratory experiment. Soil NO3-N increased as soil water-filled pore space (WFPS) increased from 0 to 80 cm3 cm−3. At soil moisture levels greater than 80 cm3 cm−3, NO3-N concentration declined rapidly and NH4-N concentration increased, likely due to anaerobic conditions existing at higher WFPS levels. Soil pH did not change as soil moisture increased from 100 g kg−1 to 400 g kg−1 and increased from 6.2 to 6.6 at higher levels of soil moisture. Soil EC was correlated with soil mineral N concentration when measured in situ with a portable EC meter (R2=0.85) or in the laboratory as 1:1 soil water slurries (R2=0.92). Results suggest that EC can be used to rapidly detect changes in soil inorganic N status in soils where salts and free carbonates are not present in large amounts.