There fertigation consists in fertilizing the soil with liquid fertilizers dissolved in water and is the standard alternative to fertilization solid for potted plants on the terrace and balcony. There fertigation it also has the advantage of evenly distributing the fertilizer in the soil, favoring its absorption by the roots.
We are so used to it that we no longer notice it, but think about it fertilize irrigating is not so obvious because it is not that the fertilizer is born liquid in the bottle or in powder in the bag. There fertigation therefore it is an elaborate and somewhat 'artificial' process (which does not mean that it is bad) and deserves some reflection.
Since all the nutrients (except the carbon dioxide contained in the air) can be assimilated by the roots only in aqueous solution, the fertilizers made with the fertigation they are immediately assimilated by the plants and do not remain on the ground, which in the pots on the balcony and terrace is not a pretty sight.
Unlike solid fertilization, however, in fertigation fertilizers are not used in their original form (manure) and are subjected to industrial processes. Compared to the good old manure Don't worry: they also exist on the market liquid fertilizers natural suitable for organic cultivation. That said, the fertigation follows the same principles as solid fertilization, with some warnings.
First of all the fertigation it must be carried out in damp and never dry soil, to avoid possible burns to the roots: it is better to wet the plant the day before with water only and then give the fertilizer always diluted in water. Applications must be done in the coolest hours of the day, taking care not to wet the flowers (would you put solid manure on the flowers?).
In doing the fertigation you must follow the doses indicated on the labels or possibly on the technical data sheets of the individual plants, but keep in mind that: instead of applying the maximum dose (e.g. 30g decalitre or a cap-measuring cup) it is preferable to make two applications spaced 4-5 days apart (15g decalitre or half cap-measuring cup).
If you use powder fertilizer for the fertigation it is a good rule to weigh or measure the necessary quantity and then dilute it in a bucket with water. Only once the powder has dissolved is the water needed to reach the desired volume added. Avoid adding the powder to the final volume of water directly in the watering can, because the fertilizer may not dissolve well and precipitate to the bottom. This problem obviously does not exist with i liquid fertilizers and emulsions.
When choosing a fertilizer for the fertigation it must be ensured that in addition to nitrogen, phosphorus and potassium there are also trace elements. On the market there are specific products for green, flowering plants, geraniums, roses, azaleas etc ... There are excellent ones compatible with the organic cultivation.