Subject
agriculture
12
cultivated plant
7
ecosystem
4
plant ecology
4
soil chemistry
4
crop
3
fertilizer
3
gardener
3
plant breeding
3
plant development
3
plant physiology
3
erosion
2
forestry
2
geography
2
microorganism
2
plant protection
2
plant soil relationship
2
soil biology
2
soil microbiology
2
soil water
2
spruce
2
vegetable
2
vocational training
2
water pollution
2
water protection
2
wood
2
Biological pest control agents.
1
Botany.
1
Crops
1
Crops.
1
Life sciences.
1
Pests
1
Plant biotechnology.
1
Plant science.
1
agronomy
1
anatomy
1
animal breeding
1
animal welfare
1
barley
1
biogeochemistry
1
biotope
1
botany
1
calculation
1
cattle
1
control engineering
1
developing country
1
ecology
1
environmental effect
1
environmental law
1
environmental policy
1
more ...