Organic fertilizers and mineral fertilizers provide plants through the soil with the nutrients they need for growth. In addition to carbon, oxygen and hydrogen that plants take from the air and water.
The main of these nutrients released by the soil (major macroelements) are nitrogen (N), phosphorus (P) and potassium (K). However, plants also feed on other elements such as: calcium, magnesium, sulfur and iron (secondary macroelements); and to a lesser extent also copper, zinc, boron, manganese, molybdenum (microelements).
To be clear, when it comes to organic fertilizers or minerals we usually refer to fertilizers that provide the main macroelements (nitrogen, phosphorus and potassium), without which plants cannot live. The products that provide the soil with secondary macroelements and microelements are instead more correctly defined as 'soil improvers' or 'corrective'.
What is the difference between organic fertilizers and mineral fertilizers? Both provide the plants with the main macro elements, the difference lies in how these elements are transferred to the soil and from it to the plants.
THE organic fertilizers (manure, poultry, guano, dried blood, bone meal ...) degrade slowly with a process called 'mineralization' (which has different times depending on the type of fertilizer) and can be assimilated by plants after weeks or months. The difference between a organic fertilizer and the other lies precisely in the times of assimilation.
Mineral fertilizers, on the other hand, disintegrate immediately (the presence of humidity is enough) and are readily assimilable. Among the fertilizers on the market there are 'simple mineral fertilizers', which contain only one of the main macroelements, and 'complex mineral fertilizers' which instead contain all three in variable quantities (the percentages can be found from the NPK formula printed on the package) .
Better i organic fertilizers or mineral fertilizers? Let's say that some do not exclude the others. A good organic fertilization of the soil should always be done, also because i organic fertilizers they also provide secondary macro elements and micro elements which are absent in mineral fertilizers. But there is a problem: in organic fertilizers only nitrogen is present in some cases (nitrogen fertilizers N, such as dry blood) and in others nitrogen and phosphorus together (nitrogen-phosphate fertilizers NP, such as manure) .
In the organic fertilizers potassium is absent, which is why it is never lacking in the third category of fertilizers on the market, namely that of 'organo-mineral' fertilizers, which contain an organic part and a mineral part. Slow-release organic fertilization is certainly suitable for preparing the seedbed and for annual fertilization, as well as for the underlying chemical balance of the soil.
Mineral fertilizers can instead be used in the vegetative and productive phase of plants, when they cannot be replaced by organic fertilizers with rapid mineralization. Always observing the recommended doses (even something less) and the 'little and often' rule.
Finally, in the use of organic fertilizers or minerals keep in mind that each of the three macroelements (NPK) performs a specific function for plant life. In particular:
- nitrogen is the most important element for the lawn and leaf plants, it is mainly used in planting and in spring recovery;
- phosphorus promotes the development of roots and flowers, and also increases the resistance of plants to diseases and cold;
- potassium helps flowering and fruiting making them abundant, improves the shelf life of the fruits and favors the lignification of plants.
Maybe you may also be interested in: Fertilize plants; How to do home composting; Natural organic fertilizers: not just manure