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Nitrate losses under various nitrogen management systems

100%

Mitchell J. K., Walker S. E., Hirschi M. C., Cooke R. A. C., Banasik K.

Zeszyty Problemowe Postępów Nauk Rolniczych

1998

tom 458

The effectiveness of nitrogen management systems in reducing the movement of nitrate in surface and sub-surface flow in the Little Vermilion River watershed is presented. Nitrate in sub-surface tile flow have been monitored for five years from fields with various tillage and cropping management practices. Water samples have also been obtained along the mainstream of the watershed. Concentrations of nitrate differed little among specific sampling locations along the river, but they definitely followed a seasonal cycle. Nitrate concentrations from the tile drains varied considerably between fields depending upon the management systems used, primarily based on the level of nitrogen fertilizer applied. The effect of the application of large amounts of nitrogen fertilizer, particularly as a pre-plant operation, is clearly shown in the nitrate-N concentrations from tile drains. The pre-plant anhydrous-N application systems with average nitrogen application of 100 kg/ha/yr. had a mean concentration of nitrate-N of 16.8 mg/L while the side-dress and manure application systems with average nitrogen application of 85 kg/ha/yr. had a mean concentration of nitrate-N of 9.8 mg/L. The mean concentration of nitrate-N from a permanent meadow field was 1.1 mg/L. Nitrate-N losses from cropped fields have ranged from 15 to 41 kg/ha/yr. depending upon the management system. Losses from the grassed system was 3.8 kg/ha/yr. and in the most upstream river station was 12 kg/ha/yr. of nitrate-N.

Ograniczanie wyników

1 Zeszyty Problemowe Postępów Nauk Rolniczych

1 Banasik K.

1 Cooke R. A. C.

1 Hirschi M. C.

1 Mitchell J. K.

1 Walker S. E.

1 1998

Wyniki wyszukiwania

Nitrate losses under various nitrogen management systems