Explain how eutrophication may occur in a lake surrounded by agricultural land.

Question

butterflydreamer · Answer

Soooo like agricultural land can be related to both animal farming/grazing and crop farming and in animal farming, there would be animal waste in the dam water and nutrients from the waste may cause an increase in BOD and lead to lower DO levels and perhaps even eutrophication?

Also, with crop farming, this includes fertilisers usually.. so then any sediment run-off could increase turbidity while fertiliser run-off into a dam can again increase BOD, lower DO levels and maybe even cause eutrophication to occur?

I know eutrophication results from the addition of nutrients (phosphates and nitrates) into waterways. 
I'm just struggling to talk about how it may occur in a lake -_-....

Any help will be appreciated ^_^ <3

Note: 
BOD -> Biochemical oxygen demand.
DO -> Dissolved oxygen

butterflydreamer · Answer

Do i need to talk about algal blooms or...? :/

nechirwan · Answer

may be this help you http://people.oregonstate.edu/~muirp/eutrophi.htm