Polyculture chemicals into the environment such as eutrophication of fresh water or the presence of excess atmospheric nitrogen are greatly reduced in polycultures. Other negative impacts of modern agriculture are similarly reduced. Excessive tillage occurs in most modern agricultural practices, but removes essential microbes and nutrients from the soil that are conserved in polycultures, especially permacultures. Agricultural machinery not only uses fossil fuels and creates waste, but is more costly to farmers. Because polyculture relies on natural systems of crop maintenance these costs can be eliminated as well. Modern agriculture is also dependent on a very limited number of plant species.
Dispersal vector excess algae and non-native plant growth. Eutrophication can lead to decreased long distance dispersal because the lack of nutrients to native plants causes a decrease in seed release height. However, because of the lowered release height, eutrophication can sometimes lead to an increase in short distance dispersal. Climate change effects on wind patterns have the potential increase average wind velocity. However, it can also lead to lower levels of wind dispersal for each individual plant or organism because of the effects climate change has on the normal conditions needed for plant growth, such as temperature and rainfall. Hydrochory is dispersal