Agriculture & Biology
soil restoration
100%
small farms
80%
sandy soils
71%
soil fertility
61%
nitrogen fertilizers
60%
zinc
35%
minerals
33%
calcium deficiency
31%
base saturation
30%
calcium
28%
corn
27%
superphosphate
27%
clay soils
25%
soil chemical properties
25%
ammonium nitrate
25%
soil organic carbon
25%
mineral fertilizers
23%
greenhouse experimentation
23%
acidification
22%
fertilizer application
21%
tropics
20%
phosphorus
16%
farmers
15%
nutrients
13%
Earth & Environmental Sciences
smallholder
82%
soil fertility
71%
sandy soil
68%
manure
64%
farm
56%
restoration
50%
calcium
21%
maize
17%
zinc
15%
superphosphate
13%
mineral fertiliser
12%
soil
12%
fertilizer application
11%
ammonium nitrate
10%
mineral
10%
acidification
9%
tropics
8%
chemical property
8%
experiment
7%
organic carbon
7%
phosphorus
6%
saturation
6%
productivity
6%
nutrient
6%
nitrogen
5%
resource
5%
effect
4%