Nutrient cycling in the Columbia River Basin eutrophication in part due to the use of the river and its tributaries to irrigate over seven million acres of farmland, an extraction that comprises an average of 93 percent of daily water use in the basin. Natural run-off caused by precipitation and snowpack melt across agricultural lands further transports more of these nutrients into the river. In the late 1990s, the nitrogen load in the Columbia river was over twice the concentration historically observed. Forests are important terrestrial sinks for nutrients due to the ability of vegetation to sequester excess nutrients into their biomass. Additionally, plant roots stabilize soils
Plant nutrition Plant nutrition Plant nutrition is the study of the chemical elements and compounds necessary for plant growth, plant metabolism and their external supply. In 1972, Emanuel Epstein defined two criteria for an element to be essential for plant growth: This is in accordance with Justus von Liebig's law of the minimum. The essential plant nutrients include carbon, oxygen and hydrogen which are absorbed from the air, whereas other nutrients including nitrogen are typically obtained from the soil (exceptions include some parasitic or carnivorous plants). There are seventeen most important nutrients for plants. Plants must obtain the following mineral nutrients from