Agriculture & Biology
drainage channels
100%
drainage systems
71%
nitrogen
39%
agricultural watersheds
28%
drainage water
22%
denitrification
20%
nitrification
20%
aquatic ecosystems
20%
agricultural soils
19%
surpluses
18%
mineralization
16%
agricultural land
16%
water
14%
agriculture
12%
crops
9%
soil
8%
sampling
6%
Earth & Environmental Sciences
flow control
55%
drainage
50%
nitrogen
40%
loss
18%
watershed
16%
drainage water
12%
watercourse
12%
water retention
12%
surplus
12%
agricultural soil
11%
drainage system
11%
aquatic ecosystem
10%
nitrification
10%
physical process
10%
denitrification
10%
agricultural land
9%
crop
8%
agriculture
8%
removal
5%
soil
4%
water
3%