Details

Autor(en) / Beteiligte

• Russelle, Michael P.
• Lamb, JoAnn F.S.
• Montgomery, Bruce R.
• Elsenheimer, Donald W.
• Miller, Bradley S.
• Vance, Carroll P.

Titel

Alfalfa Rapidly Remediates Excess Inorganic Nitrogen at a Fertilizer Spill Site

Ist Teil von

• Journal of environmental quality, 2001-01, Vol.30 (1), p.30-36

Ort / Verlag

Madison: American Society of Agronomy, Crop Science Society of America, Soil Science Society

Erscheinungsjahr

2001

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• By 1996, standard remediation techniques had significantly reduced the concentration of nitrate nitrogen (NO−3–N) in local ground water at the site of a 1989 anhydrous ammonia spill, but NO−3–N concentrations in portions of the site still exceeded the public drinking water standard. Our objective was to determine whether local soil and ground water quality could be improved with alfalfa (Medicago sativa L.). A 3‐yr study was conducted in replicated plots (24 by 30 m) located hydrologically upgradient of the ground water under the spill site. Three alfalfa entries [`Agate', Ineffective Agate (a non‐N2–fixing elite germplasm similar to Agate), and MWNC‐4 (an experimental germplasm)] were seeded in the spring of 1996. Corn (Zea mays L.) or wheat (Triticum aestivum L.) was seeded adjacent to the alfalfa each year. Crops were irrigated with N‐containing ground water to meet water demand. During the 3‐yr period, about 540 kg of inorganic N was removed from the aquifer through irrigation of 4.9 million L water. Cumulative N removal from the site over 3 yr was 972 kg N ha−1 in Ineffective Agate alfalfa hay, compared with 287 kg N ha−1 for the annual cereal grain. Soil solution NO−3 concentrations were reduced to low and stable levels by alfalfa, but were more variable under the annual crops. Ground water quality improved, as evidenced by irrigation water N concentration. We do not know how much N was removed by the N2–fixing alfalfas, but it appears that either fixing or non‐N2–fixing alfalfa will effectively remove inorganic N from N‐affected sites.