Agriculture & Biology
long term experiments
96%
nutrient management
90%
soil acidification
65%
fertilizers
59%
soil fertility
57%
nitrogen fertilizers
56%
crop yield
55%
nutrient use efficiency
52%
China
50%
management systems
47%
farmers
44%
crops
41%
cropland
37%
organic fertilizers
34%
food security
31%
nutrients
28%
groundwater contamination
21%
traditional farming
21%
small-scale farming
20%
continuous cropping
20%
nitrogen
18%
sustainable development
17%
greenhouse gas emissions
17%
crop management
17%
vegetable crops
17%
intercropping
17%
fruit trees
16%
soil pH
15%
leaching
15%
fertilizer application
14%
cropping systems
14%
ammonium
14%
soil quality
14%
weather
13%
hands
13%
nitrates
13%
farming systems
12%
legumes
12%
urea
12%
uptake mechanisms
10%
rice
10%
carbon
10%
wheat
10%
corn
9%
Earth & Environmental Sciences
long-term experiment
100%
fertilizer
52%
nutrient
50%
crop
43%
chemical fertilizer
43%
nutrient use efficiency
42%
soil fertility
37%
crop yield
37%
soil acidification
33%
crop rotation
32%
organic fertiliser
21%
food security
17%
demand
16%
continuous cropping
13%
intercropping
12%
fruit tree
12%
yield response
12%
groundwater pollution
10%
nitrogen
10%
world
9%
resource
9%
cereal
9%
farming system
9%
soil quality
9%
vegetable
8%
urea
8%
cropping practice
8%
weather condition
8%
wheat
7%
management practice
7%
maize
7%
greenhouse gas emissions
7%
rice
7%
ammonium
7%
sustainable development
7%
leaching
6%
plain
6%
nitrate
6%
sensor
5%
services
5%
carbon
4%
loss
4%
soil
3%
rate
2%
Chemical Compounds
Fertilizer
95%
Nutrient
83%
Soil Fertility
77%
Crop Rotation
70%
Soil Acidification
69%
Organic Fertilizer
38%
Reaction Yield
22%
Groundwater Pollution
20%
Food
15%
Nitrogen
13%
Environment
12%
Leaching
10%
Soil
9%
Nitrate
8%
Application
7%
Carbon Atom
5%
pH Value
4%
Surface
3%
Engineering & Materials Science
Nutrients
98%
Fertilizers
85%
Soils
35%
Experiments
27%
Acidification
25%
Groundwater pollution
10%
Nitrogen
10%
Vegetables
7%
Nitrates
7%
Urea
6%
Leaching
6%
Fruits
6%
Gas emissions
5%
Greenhouse gases
5%
Sustainable development
4%
Synchronization
4%
Carbon
4%
Sensors
2%