We all need to eat. vegetables - and other plants are no exception!
The difference between success and good vegetable crops is often down to the feeding regime, and the types of fertilisers or manures that you use.
Always remember, that what you put into vegetables, you will eventually put into yourself! Don't worry though, all garden fertilisers go through a complex change of form to make them available for the vegetables and safe for us to eat
Organic or not is a question you will have to answer for yourself. Whatever the feeding method you adopt, the chemicals will have to be broken down in the soil through various processes to make them available as food that the plant can absorb.
It is folly to think that organic fertilisers do not contain chemicals. If they did not contain the chemicals that the plants require, then they would be no use to the plant. As with non-organic fertilisers, all organic feeds or manures have to be broken down into a series of chemicals that plants can actually absorb through their root system and then feed the plant. Plants cannot eat leaves, or horse manure, or well made compost. Plants can only feed on the chemicals that all feeds break down into! More of that later.
Just think about how the average vegetable plot is managed. Year after year, we sow seeds, grow large plants with leafy tops and swollen roots and tubers. All of this growth takes nutrients out of the soil. In most garden areas, this does not happen. In the shrub border, we leave the same plants in the same place for many years. Very often, food is returned back to the soil by fallen leaves, or by the mulches that we put on to cover the weeds etc. Same with the perennial borders, and bulbs. All are left in the soil, needing very little in the way of added feed to keep them growing well. natural re-cycling of leaves and other debris, keeps the soil nutrients at a constant level.
Just look at the nutrient store locked up in the photo of Florence Fennel! The Fennel - as with all other vegetables are removed from the soil - together with the store of nutrient that they have taken out of the soil.
The only other place in the garden where soil food reserves are removed on such a large scale. is the garden lawn! Week after week, we cut the grass and remove the soil nutrients - sometimes to the compost heap, but often to the bin! And the lawn, like the vegetable plot, needs to be regularly fed if we wish it to stay in good condition.
In the case of the vegetable plot, we want healthy, succulent vegetables. To have these, we need to regularly replace all the nutrients that we take out of the soil - via our crops - to feed ourselves. Eventually, what you put into the vegetable plot by way of fertilisers and manures, is converted by the plants into plant tissue, which is then the basis of our healthy diet! (Takes tongue out of cheek!)
That is the very simple explanation of why vegetables need feeding more than most other areas of the garden. Vegetables - as with any other plants - are very complex organisms that can convert many types of soil chemicals into the food they require.