| Abstract: | The ability of carrot, leek and white cabbage to deplete the soil inorganic nitrogen (N) pool was studied. All three crops are late-harvested crops with a long growing season, but they have been found to have very different root growth. At their optimal N supply, carrot left 27 kg nitrate-N ha-1 in the top 100 cm of the soil, leek left 87 kg N ha-1 and white cabbage left only 11 kg N ha-1, in accordance with previously published differences in rooting depth among the three crops. Compared at a supply of 160 kg N ha-1, 52, 65 and 4 kg nitrate-N ha-1 was left in the soil by carrot, leek and white cabbage respectively. Apart from an extensive root system, white cabbage also had a much higher N-uptake capacity than the two other crops. The significance of differences in root growth, N-uptake capacity and other factors in determining the ability of the three crops to deplete the soil inorganic N pool is discussed. |
