Nitrogen Management Effects on Soil Health and Environmental Quality.

Nitrogen is the fertilizer nutrient most commonly limiting crop production and is applied in the greatest amount in most crop production systems. Addition of fertilizer N can affect a number of soil properties and functions with the magnitude of that effect depending on the form, timing, amount of N applied, and interactions with other management practices (tillage, rotation, cover crops, and water). A partial list of soil properties responding to N addition includes: soil organic matter, enzyme activity, microbial biomass and respiration, pH, and electrical conductivity. Changes in these properties will affect soil functions such as gas exchange with the atmosphere, water infiltration and storage, and nutrient storage and availability. Management induced changes in soil health result in environmental impacts. Poor management results in loss of sediment and N to surface water, leaching of N to groundwater, increase in greenhouse gas emissions. Management practices that improve soil health also contribute to improved air and water quality.