Earth & Environmental Sciences
cover crop
100%
cropping practice
74%
nitrogen
44%
tillage
39%
maize
33%
cash crop
26%
crop
20%
manure
18%
mulch
12%
crop rotation
11%
synchrony
11%
source of pollution
10%
cereal
10%
farming system
10%
loss
9%
planting
9%
fixation
9%
harvest
8%
fertilizer
8%
soil
7%
air quality
7%
mineralization
6%
demand
6%
services
5%
biomass
5%
economics
5%
need
5%
experiment
3%
method
2%
Agriculture & Biology
cover crops
82%
cropping systems
71%
nitrogen
43%
tillage
41%
corn
26%
cash crops
26%
cover crop termination
18%
waterways
14%
air quality
13%
crop management
12%
crops
11%
grain crops
11%
aboveground biomass
10%
soil
10%
management systems
10%
no-tillage
10%
phytomass
10%
mineralization
10%
pollution
9%
planting
8%
fertilizers
8%
farmers
7%
economics
7%
methodology
2%