To live and grow a plant needs light, water and nutrients. It will draw directly into the soil water and different nutrients. Therefore, it is important that you maintain the fertility of your soil by regularly providing garden fertilizer.
The nutrient requirements of garden plants
Plants need mainly macronutrients that is to say nitrogen, phosphorus and potassium:
- nitrogen (chemical symbol N). It contributes to foliage development and stems or branches. It is a major fertilizer in the spring when vegetation is recovering. But beware, used in excess not only it pollutes water and soils but it unbalances the plants that then produce more leaves at the expense of flowers and fruits. The most demanding nitrogen plants are grass, grasses, bamboo and leafy vegetables.
- Phosphorus (chemical symbol P). It contributes to root development and enhances plant resistance to disease. Used in excess it contributes to the eutrophication of water (that is to say the proliferation of algae). The most demanding plants in phosphorus are the flower and fruit species as well as the vegetable seeds.
- Potassium (chemical symbol K). It contributes to flowering and fruit development. The most demanding plants in potassium are fruit trees, flowering shrubs, roses, bulbs and root vegetables.
Fertilizers can consist of only 1 element or 2 or combine the 3 in variable proportion. The initials NPK are then followed by numbers indicating the exact composition. For example NKP 16-5-5 indicates a fertilizer containing 16% nitrogen (N), 5% phosphorus (P) and 5% potassium (K).
In lesser proportion, plants also need to secondary nutrientsCalcium (C), sulfur (S) and magnesium (Mg) as well as trace elements Iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), silicon (Si), etc..
Many fertilizers combine these different elements to form complete ready-to-use formulas. But most of the time, unless there is a soil imbalance or its PH, the secondary nutrients are naturally present in sufficient quantity. Before any fertilizer intake, the ideal is to make analyze his soil to know the strengths and imbalances.
The different types of fertilizer
Macronutrients, secondary nutrients and trace elements come from different sources. So nitrogen is present in dried blood which is an organic fertilizer and in nettle manure which is considered an ecological fertilizer. Phosphorus is derived from phosphate rock, so it is a mineral fertilizer but it is also found in the bone powder which is an organic fertilizer. It is the same for potassium. Not to mention that N, P and K can also come from the chemical industry... It is not by their composition that we can recognize this or that type of fertilizer but rather by their manufacture or their origin.
- Chemical fertilizersThese are synthetic products made from chemical elements.
- Theorganic fertilizers: They are of animal origin (bone powder or fish bones, dried blood, crushed horn, guano) or vegetable (seaweed, nettle or comfrey manure, ash, sugar beet vinasse residue, etc. ).
- Mineral fertilizersThey come from natural deposits of inert minerals such as potash or phosphate. But most of the time, they are actually made from chemical elements.
- Ecological or natural fertilizers: These are natural mineral fertilizers, organic fertilizers when they come from natural plant or animal matter. Stout nettle and comfrey are considered ecological fertilizers.
- Green manuresThese are fast-growing plants (clover, alfalfa, lupine, faba bean, etc.) that are sown and then buried on site to provide a natural fertilizer rich in organic matter. In the garden, before installing a lawn is a good way to fertilize the land.