Columbia subject headings:
Animal waste--Environmental aspects.
Fertilizers--Environmental aspects.
Groundwater--Pollution.
Nitrates--Environmental aspects.
Pesticides--Environmental aspects.
Harvard subject headings:
Agricultural pollution.
Fertilizers--Environmental aspects.
Pesticides--Environmental aspects
Water--Pollution
Princeton subject headings:
Animal waste--Environmental aspects--Developing countries.
Fertilizers--Environmental aspects--Developing countries.
Groundwater--Pollution--Developing countries.
Nitrates--Environmental aspects--Developing countries.
Pesticides--Environmental aspects--Developing countries.