Nitrogen

Nitrogen is one of three key elements needed by plants. (phosphorus P and potassium K being the other two). The plants use nitrogen to build up amino acids and proteins This therefore is the element that is responsible for vegetative growth of plants.

Being perdanic, there are also three other key elements needed, Carbon C Oxygen O and Hydrogen H. Carbon Dioxide (CO₂) and Water (H₂O) providing the plant with these elements.

The technical bit

Other facts

• Nitrogen comes from the Greek word 'nitron genes' which means 'nitre'  and 'generator'
• Discovered by Daniel Rutherford, Scotland, 1772
• In 1776 French scientist, Antoine Laurent Lavoisier declared it an element.
• 78% of the air is made up of nitrogen gas specifically dinitrogen N2.
• Lightning causes natural production of ammonium nitrate, (NH4NO3) that is dissolved by the rain and thus ready to be taken up by plants.

Nitrogen and the gardener

Nitrogen as mentioned above is responsible chiefly for the vegatative growth in plants, therefore plants must have a means of obtaining nitrogen. Since nitrogen in the air is not taken up by the plants it follows that it must be the root system. It is the nitrogen compounds that are taken up by the plants, ammonium nitrate for example that is made by lightning. Since plants contain nitrogen it is logical to assume that when these rot down compounds of nitrogen are released into the soil which are again taken up by plants. Animals when they urinate pass nitrogen compounds into the soil too. These were nature's methods of ensuring plants got sufficient nitrogen to survive and prosper before man began cultavation.

The cheapest way of supplying nitrogen to plants is in using decaying organic matter, either as a top dressing or by incorporating into the soil when digging. Over a long period of time nitrogen contained is slowly released and made available to the plants. Organic gardeners or those wishing to maintain our natural resources can use poultry manure pellets, dried blood, fish emulsions, sewerage sludge. Sulphate of Ammonia is available to non organic gardeners. There is also combined fertilisers like Growmore and those from differing manufacturers.