Subject
humic substance
humic acid
3
soil
2
soil biology
2
soil chemistry
2
biomass
1
carbohydrate
1
chemical analysis
1
degradation
1
ecosystem
1
environmental health
1
enzyme
1
fungus
1
global aspect
1
humus
1
microorganism
1
minerals
1
nematode
1
organic compound
1
organic matter
1
soil mechanics
1
soil microbiology
1
soil physics
1
soil science
1
soil water
1
sulfur cycle
1
water
1