Agriculture & Biology
greenhouse gases
100%
bioenergy
93%
cropping systems
80%
energy crops
71%
Panicum virgatum
63%
soil organic carbon
48%
biomass
26%
fossil fuels
24%
nitrogen fertilizers
19%
species diversity
16%
carbon sinks
12%
renewable energy sources
11%
soil depth
11%
carbon nitrogen ratio
11%
soil
10%
ethanol production
10%
soil fertility
9%
sowing
8%
grasses
7%
farms
7%
carbon
6%
nitrogen
6%
Earth & Environmental Sciences
cropping practice
84%
greenhouse gas
73%
mitigation
65%
polyculture
32%
crop
30%
organic carbon
21%
soil
18%
biomass
17%
fossil fuel
12%
fertilizer
12%
shallow soil
8%
nitrogen
8%
carbon
8%
seeding
7%
fertility
7%
soil depth
7%
ethanol
6%
species diversity
6%
alternative energy
6%
grass
6%
farm
6%
effect
1%
Engineering & Materials Science
Greenhouse gases
85%
Organic carbon
64%
Soils
58%
Fossil fuels
20%
Nitrogen fertilizers
19%
Carbon
16%
Biodiversity
15%
Fertilizers
13%
Ethanol
10%
Farms
10%
Nitrogen
9%
Renewable energy resources
8%
Chemical analysis
6%