Leaching (agriculture)

Soil structure, crop planting, type and application rates of fertilizers, and other factors are taken into account to avoid excessive nutrient loss.

Of particular concern are hazardous waste dumps and landfills, and, in agriculture, excess fertilizer, improperly stored animal manure, and biocides (e.g. pesticides, fungicides, insecticides and herbicides).

Livestock then eat the crops producing manure, which is returned to the soil, adding organic and mineral forms of nitrogen.

However, soils do not absorb the excess NO3– ions, which then move downward freely with drainage water, and are leached into groundwater, streams and oceans.

[5] Phosphorus (P) is a key nutrient regarding the eutrophication of surface waters and has been shown to limit algae growth in lake environments.

Important potential adsorption sites for P in soils are surfaces of iron and aluminum oxides or hydroxides such as gibbsite or ferrihydrite.

A decrease in the soils redox potential due to prolonged water saturation may lead to reductive dissolution of ferric iron minerals that are important P sorption sites.

Finally, leaching of NO3 from acidic sources can increase the loss of calcium and other soil nutrients, thereby reducing an ecosystem's productivity.