Nitrate-nitrogen Removal from Soil Profiles by Alfalfa1
- A. C. Mathers,
- B. A. Stewart and
- Betty Blair2
Alfalfa (Medicago sativa L. ‘Cody’) was established in the fall of 1971 on plots previously treated with 0, 22, 45, 112, or 224 metric tons/ha of manure annually for 3 years. Additional plots had received 224 kg N/ha (as NH4NO3) annually for 3 years. Nitrate-nitrogen and water contents of the soil profile were determined by 30-cm increments to 6 m prior to planting. Nitrate-nitrogen was found to 6 m, but the largest concentrations were in the top 1.8 m, where amounts of NO3−-N varied from 100 to 2,400 kg/ha. Additional profile samples were taken in 1972 and 1973 after the final cutting of alfalfa. The data showed that alfalfa removed water and NO3−-N to a 1.8-m depth the first year and to 3.6 m the second year. These results indicate that alfalfa could remove NO3−-N from the lower depth of soil profiles where annual crops were not effective. Yield, NO3−-N, and P contents of alfalfa were increased by manure. Total N taken up by the crop was directly related to the yield.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .