Fate of fertilizer nitrogen applied to grassland. II. Nitrogen-15 leaching results |
| |
| Authors: | D BARRACLOUGH E L GEENS J M MAGGS |
| |
| Institution: | Jealott's Hill Research Station, Bracknell, Berkshire |
| |
| Abstract: | Results are presented from a 3-year investigation into nitrate leaching from grassed monolith lysimeters treated with double (15NH415NO3) or single (15NH4NO3) labelled ammonium nitrate at three rates, 250, 500 and 900 kg N ha?1 a?1. Over the 3 years of the experiment, 0.14%, 3.1% and 18.1% of the applied fertilizer was recovered in the leachate at 250, 500 and 900kg N ha?1 respectively. This represented 9%, 39% and 75% of the overall nitrate leaching at the three application rates. A significant proportion of the fertilizer leached as nitrate at the three application rates was derived, via nitrification, from the fertilizer ammonium. Increasing fertilizer applications caused a rise in the leaching of both soil and fertilizer derived nitrogen, although whether the increase reflected a true priming effect was not clear. |
| |
| Keywords: | |
|
|
