In response to increasing levels of nitrate-N in groundwater in the Central Platte River Valley of Nebraska, intensive education and then regulatory efforts were implemented starting in the 1980s, to encourage adoption of nitrogen fertilizer and irrigation management practices which can reduce nitrate leaching to groundwater. Since 1988, there have been steady declines in average NO3-N concentrations in groundwater in the Central Platte River Valley, resulting from adoption of recommended practices – in particular conversion from furrow to center-pivot irrigation. However, fertilizer nitrogen use efficiency has remained fairly static over the past 25 years. Trends suggest that further improvement in nitrogen use efficiency may require development and adoption of next generation nutrient management tools, such as increased use of fertigation, controlled release formulations, or crop canopy sensors for in-season fertilization.
Soil Science Extension
University of Wisconsin Madison