Fertilizers and testing for nitrates.

by daniela1973 (student)

Fertilizers

Mined inorganic fertilizers have been used for many centuries, whereas chemically synthesized inorganic fertilizers were only widely developed during the industrial revolution. Increased understanding and use of fertilizers were important parts of the pre-industrial British Agricultural Revolution and the industrial Green Revolution of the 20th century

Fertilizers (also spelled fertilisers) are compounds given to plants to promote growth; they are usually applied either via the soil, for uptake by plant roots, or by foliar feeding, for uptake through leaves. Fertilizers can be organic (composed of organic matter), or inorganic (made of simple, inorganic chemicals or minerals). They can be naturally occurring compounds such as peat or mineral deposits, or manufactured through natural processes (such as composting) or chemical processes (such as the Haber process).

Fertilizers typically provide, in varying proportions, the three major plant nutrients (nitrogen, phosphorus, and potassium), the secondary plant nutrients (calcium, sulfur,magnesium), and sometimes trace elements (or micronutrients) with a role in plant nutrition: boron, chlorine, manganese, iron, zinc, copper, and molybdenum.

In the past, both organic and inorganic fertilizers were called "manures," but this term is now mostly restricted to man-made manure.

Though nitrogen is plentiful in the Earth's atmosphere, relatively few plants engage in nitrogen fixation (conversion of atmospheric nitrogen to a biologically useful form). Most plants thus require nitrogen compounds to be present in the soil in which they grow.

Justus von Liebig invented fertilziers He is known as the "father of the fertilizer industry" for his discovery of nitrogen as an essential plant nutrient, and his formulation of the Law of the Minimum which described the effect of individual nutrients on crops.

Fertilizer adds nutrients and texture to soil that needs to provide nutrients to trees, vegetables, herbs, shrubs and flowers. There are several ways to categorize fertilizer, and the most basic is whether it is organic or inorganic. It also can be classified according to its ingredients, whether it is solid or liquid and by its particular actions, such as slow-releasefertilizers that dissolve and release their nutrients slowly. The choice of fertilizer that is used typically depends on the nature of the soil, such as whether it is acidic or alkaline; sandy, clay or rocky; and weak ...