Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 6/12/1998
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Economical and efficient means of nitrate remediation are needed to prevent the spread of nitrate-impacted ground water into drinking water supplies. We suggest using nitrate-impacted ground water to irrigate alfalfa (Medicago sativa L.). Where alfalfa is adapted, it can produce very high yields with high protein concentration, resulting in large N removal rates in harvested forage. In addition, nonassimilated nitrate-N concentrations usually remain low in herbage, even with high nitrate supply. High water use by alfalfa also allows greater water removal from the aquifer than with annual grain crops, and the high value of alfalfa hay helps offset irrigation costs. When inorganic N supply is adequate, an adapted special purpose (ineffectively nodulated) alfalfa will be 30 to 40% more efficient at removing nitrate than standard alfalfas. In cooperative research with Canadian Pacific Railway, we found that 'Ineffective Agate' alfalfa removed d425 kg N/ha in one cropping season at a rail car spill site in ND, whereas adapted grain crops typically remove only 20 to 40% as much N.