View Full Table | Close Full ViewTable 1.

Losses of dissolved organic nitrogen (DON), nitrate, and dissolved organic carbon (DOC) across a diverse array of agricultural systems with various rates of N inputs.

 
N input Leached
Cropping system Method Precipitation Texture Manure Inorganic DON Nitrate DOC DON Reference
mm yr−1 kg ha−1 yr−1 %†
Ryegrass/maize‡ Suction cup 742 Sandy 108 62 8.6 50 30§ 15 Siemens et al., 2002, 2003
Ryegrass/maize‡ Suction cup 742 Sandy 161 41 9.2 59 38 13 Siemens et al., 2002, 2003
Fallow‡ Suction cup 742 Sandy 0 0 4.7 2.5 33 65 Siemens et al., 2002, 2003
Fallow/sheep‡ Suction cup 742 Sandy 0 0 4.0 17 96 19 Siemens et al., 2002, 2003
Maize/soybean/chisel§ Lysimeter 900 Silt-loam 150 0.4 0.8 nr# 33 Shuster et al., 2003
Maize/soybean/chisel¶ Lysimeter 900 Silt-loam 150 3.8 6.4 nr 37 Shuster et al., 2003
Maize/soybean/ridge§ Lysimeter 900 Silt-loam 150 2.1 4.4 nr 32 Shuster et al., 2003
Maize/soybean/ridge¶ Lysimeter 900 Silt-loam 150 3.1 8.9 nr 26 Shuster et al., 2003
Cabbage Suction cup 1400 Silt-clay-loam 40–60 0.9 4.1 17.2 18 Moller et al., 2005
Grass-clover/fallow Suction cup nr Coarse sandy 120 31 316 216 9 Vinther et al., 2006
Grass-clover Suction cup nr Sandy loam 0 0 3.3# 10.5 28.3 24 Vinther et al., 2006
Grass-clover/barley Suction cup nr Coarse sandy 120 20 303 174 6 Vinther et al., 2006
Grass-clover Lysimeter 627 Sandy loam 220 0.3 0.9 nr 25 Saarijarvi et al., 2004
Grass-clover/roundup Lysimeter 627 Sandy loam 2.8 26.4 nr 10 Saarijarvi et al., 2004
Grass/grass clover Lysimeter 567†† Sandy loam 65 110 0.5 12.3 nr 4 Saarijarvi et al., 2007
Plowed-barley/grass Lysimeter 545†† Sandy loam 5.5 40.2 nr 12 Saarijarvi et al., 2007
Grassland-mono‡‡ Lysimeters 660 nr 0 1.6 18.8 nr 8 Dijkstra et al., 2007
Grassland-mono‡‡ Lysimeter 660 nr 40 3.0 30.0 nr 9 Dijkstra et al., 2007
Grassland-diverse‡‡ Lysimeter 660 nr 0 3.5 2.3 nr 60 Dijkstra et al., 2007
Grassland-diverse‡‡ Lysimeter 660 nr 40 3.8 2.8 nr 58 Dijkstra et al., 2007
Pasture Basin nr Sandy-clay-loam 100 4 13 nr 24 Watson et al., 2000
Pasture Basin nr Sandy-clay-loam 200 4.3 21.5 nr 17 Watson et al., 2000
Pasture Basin nr Sandy-clay-loam 300 4.3 35 nr 11 Watson et al., 2000
Pasture Basin nr Sandy-clay-loam 400 4.5 57.6 nr 7 Watson et al., 2000
Pasture Basin nr Sandy-clay-loam 500 3.5 63 nr 5 Watson et al., 2000
Pasture§§ Lysimeter 824 nr 1030¶¶ 127 542 nr 19 Wachendorf et al., 2005
Pasture§§ Lysimeter 824 nr 1052## 23 94 nr 20 Wachendorf et al., 2005
Pasture Lysimeter 1200 Silty sand 200 2.2 7.7 nr 22 Korsaeth et al., 2003
Pasture Lysimeter 1200 Silty sand 195 4.8 15.7 nr 23 Korsaeth et al., 2003
Pasture Lysimeter 1200 Silty sand 127 80 2.5 11.6 nr 18 Korsaeth et al., 2003
Pasture Lysimeter 1200 Coarse sand 127 80 13.3 33.0 nr 29 Korsaeth et al., 2003
Turfgrass/high irrigation Lysimeter 859††† Sandy 433‡‡‡ 38 45 nr 46 Barton et al., 2006
Turfgrass/high irrigation Lysimeter 859 Sandy 433§§§ 47 47 nr 50 Barton et al., 2006
Turfgrass/low irrigation Lysimeter 859 Sandy 433 20 7 nr 74 Barton et al., 2006
Turfgrass/low irrigation Lysimeter 859 Sandy 433 33 7 nr 83 Barton et al., 2006
Fruit trees Suction cup 2500 Clay 100 1.2¶¶¶ 1.3 nr 48 Renck and Lehman, 2004
Cereals Tile drain 842### Silty-clay-loam 240 7 52 nr 12 Murphy et al., 2000
Cereals Tile drain 842 Silty-clay-loam 216 1.8 17.8 nr 9 Murphy et al., 2000
Cereals Tile drain†††† 775‡‡‡‡ Silty-clay-loam 88 0.6§§§§ 48 nr 1 Lawes et al., 1881
Grassland Suction plate 587 Sandy-loam/silty clay 0 0 0.9¶¶¶¶ 1.3 nr 41 Oelmann et al., 2007
Grassland Basin nr Clay 0#### 0 6.2 2.7 108 70 Frank et al., 2000
Calculated as [DON/(DON + NO3)] × 100.
Losses averaged across 3 yr.
§ Across tillage and earthworm treatments.
Average of 1, 8, and 9-yr clover sward.
# nr is not reported.
†† Calculated from Table 2 in Saarijarvi et al. (2004)
‡‡ Across CO2 treatments.
§§ Average across 2 yr.
¶¶ Applied as urine, and mimicking a urine patch.
## Applied as dung and mimicking a dung patch.
††† High irrigation is equal to 140% of daily replacement of pan evaporation; low irrigation is equal to 70% of daily replacement of pan evaporation.
‡‡‡ Average for water soluble and control-release fertilizer.
§§§ Average for pelletised poultry manure and biosolids.
¶¶¶ At 2 m depth.
### Obtained from the Rothamsted archives.
†††† Based on data collected from a drain-gauge placed at 150 cm depth.
‡‡‡‡ Average rainfall between 1873 and 1879.
§§§§ Average based on 4 yr (1877–1881).
¶¶¶¶ Average of seven different levels of species richness and five different functional groups of grasses, small herbs, tall herbs, and legumes.
#### Grassland was in fallow for 15 yr at the initiation of the experiment.



View Full Table | Close Full ViewTable 2.

Concentrations of dissolved organic nitrogen (DON) and nitrate in leachates collected from agricultural systems. See Table 1 for further experimental details.

 
Cropping system Depth DON† Nitrate‡ Reference
m mg N L−1
Ryegrass/maize 0.90 2.4 12.6 Siemens et al., 2003
Ryegrass/maize 0.90 2.6 18.6 Siemens et al., 2003
Fallow 0.90 1.8 9.0 Siemens et al., 2003
Fallow/sheep 0.90 1.5 5.8 Siemens et al., 2003
Maize/soybean/chisel till§ 0.45 1.6 2.9¶ Shuster et al., 2003
Maize/soybean/chisel till# 0.45 3.2 6.8¶ Shuster et al., 2003
Maize/soybean/ridge till§ 0.45 2.6 4.6¶ Shuster et al., 2003
Maize/soybean/ridge till# 0.45 3.5 6.0¶ Shuster et al., 2003
Cabbage 0.80 0.2†† 2.5 Moller et al., 2005
Grass-clover/sandy 0.90 1.4 0–10 Vinther et al., 2006
Grass-clover/coarse sand 0.7 1.2–3.1 Vinther et al., 2006
Grassland-mono, low N‡‡ 0.60 0.7 7.2 Dijkstra et al., 2007
Grassland-mono, high N‡‡ 0.60 1.2 13.5 Dijkstra et al., 2007
Grassland-diverse, low N‡‡ 0.60 1.6 1.1 Dijkstra et al., 2007
Grassland-diverse, high N‡‡ 0.60 1.8 0.8 Dijkstra et al., 2007
Turfgrass, low irrigation/manure-N§§ 0.98 Barton et al., 2006
Turfgrass, low irrigation/inorganic N§§ 0.98 Barton et al., 2006
Turfgrass, high irrigation/manure-N§§ 0.98 Barton et al., 2006
Turfgrass, high irrigation/inorganic-N§§ 0.98 Barton et al., 2006
Pasture¶¶ NA## 1.6††† Watson et al., 2000
Pasture‡‡‡ NA## 1.1††† Watson et al., 2000
Values above 1.0 mg L−1 of Kjeldahl N (organic N plus NH4 +) exceeds the allowable concentration in the EU for drinking water quality.
Values above 11.3 NO3 –N L−1 in the EU and 10 mg of NO3 –N L−1 in the United States exceeds the allowable concentration for drinking water quality.
§ Ambient earthworm population, average across years and management phases.
Value include NO2 and NH4 +
# 100 earthworms per m2 added; averaged across years and management phases.
†† Values calculated from Tables 4 and 5 in Dijkstra et al. (2007)
‡‡ Across CO2 treatments.
§§ Averaged across two manure or two inorganic N treatments. Median values based on at least 138 values.
¶¶ Average across five rates of N fertilizer applications.
## Depth not applicable as drainage water samples were collected at a weir.
††† Total Kjeldahl N (organic N plus NH4 +).
‡‡‡ Average annual flow-weighted mean concentrations of six river catchments.