To be able to benefit from abundant harvests, the gardener must take care to cultivate his plants in the vegetable garden in a soil capable of providing them with all nutrients they need, trace elements, and mineral elements. However, it may happen that some plants poorly assimilate some of these elements or that the nutrients are lacking. This is how we talk about sun lacked. The plants then show symptoms that can put the gardener on the right track, such as slow growth, yellowing or signs of discoloration in the leaf system, or even a decline in production. In order to correct the deficient soil of your vegetable garden, it is therefore essential to know which element is insufficient. Let’s do a check in.
Vegetable garden soil: the different types of deficiencies
In the soil, plants draw many mineral elements that are essential to them, namely:
- Trace elements including manganese, zinc, chlorine, iron, copper, molybdenum or even boron,
- Macroelements such as calcium, sulphur, magnesium, potassium, nitrogen, phosphorus…
Among them are three basic elements – nitrogen (N), phosphorus (P) and potassium (K), absolutely major – while the others are present in the garden soil in lesser quantities, sometimes in the form of traces. The fact remains that all without exception contribute to the good health of plants, even if some are not absolutely vital, as is the case with sodium, silicon, vanadium or even cobalt. It should be noted that in addition, it is in the water of the ground that the plants draw oxygen and hydrogen which are just as essential to them but which they need just as much light and air.
The slightest imbalance is unfavorable for the plant organism. When we talk about deficiency at ground level, we can be faced with one of the following problems:
- A poor assimilation of an element by the plant,
- And imbalance between the different elements of the vegetable garden soil,
- L’insufficiency one or more nutrients,
- L’excess elements due to an irrational amendment.
In all cases, the physiological mechanisms of the plants in the vegetable garden may be disturbed.
Deficient vegetable garden soil: the different means of assessment
Different solutions make it possible to check the level of fertility of the soil in the vegetable garden and to ensure the good nutrition of his plants.
In case of deficiency, symptoms do not take long to appear in certain plants (because they do not all have the same needs), such as:
- Slowed or stopped growth
- Foliage color anomalies,
- Burns or necrosis on certain plant parts,
- Excessive leaf growth,
- A lack of flowering or fruiting…
The simple observation of his crops can already put the flea in the ear of the gardener provided that he has a little experience in the matter because the confusion is quite possible. Some symptoms may have various unrelated origins. For example, necrosis can be due to a potassium deficiency but also to trauma or even to a pathogen. It is therefore clear that observing the symptoms from which some plants in the vegetable garden suffer is important, but this is enough to be certain that the soil of the vegetable garden is deficient.
Observation of the local flora
The local plants that grow spontaneously in the vegetable garden say a lot… a lot about the composition of the soil and it is important to observe them before planting anything to know if the soil is fertile. Excellent bioindicatricesthem weeds are, contrary to what is too often thought, allies of the gardener.
The year before starting a vegetable garden should be used for preparation. It is very useful to begin by listing over the four seasons all the species of wild plants that grow on the plot as well as their density. A little here or there does not mean much, whereas a large concentration of local plants in the same area gives valuable indications on the nature du sol, its richness or its poverty in nutritional elements. The same vegetables are not grown in fertile or infertile soil, in draining or waterlogged soil, in sandy and loose or clayey and compact soil. Similarly, we do not find the same plants depending on whether the soil is very rich or poor in nitrogen, for example.
From nettle to dandelion, from field bindweed to white clover… wild grass are the real ones ground messengers. So we take the time to watch them live in order to better understand the soil of our vegetable garden.
Soil and plant tissue analysis in the laboratory
This is by far the safest technique for obtaining a precise dosage of bioavailable elements essential for plant nutrition. Soil analysis, both chemical and physical, is certainly interesting, but it is not enough on its own to determine if there is a real deficiency since all plants do not have the same needs. It is therefore also necessary to carry out the analysis of plant tissues in order to be able to measure the specific nutrient requirements of each species or variety and to check whether the nutrients are properly assimilated.
It is by coring to the agronomic probe that different samples of arable land are taken (by specialists) so that a very detailed analysis of the soil can be carried out. If this is commonplace in the field of agriculture, it is much less so in the private sector.
The analysis report indicates, among other things:
- The identification of deficiencies since the content of carbon, trace elements and macroelements is measured,
- heavy metals,
- The proportion of humus,
- The Hydrogen potential (pH), i.e. whether the soil is neutral, acid, alkaline,
- The type of soil,
- The particle size…
After knowing all these results, it is easier to select plants to grow in the vegetable garden depending on its type of soil and all its characteristics. Indeed, we should always grow plants adapted to the environment they are offered. This considerably limits problems of all kinds.
It is therefore in spring or autumnand before drawing the plan of his vegetable garden, that a gardener should have this real inventory by submitting soil samples to a laboratory. He can also use this process to find out the true origin of a recurring problem jeopardizing his successive crops or even if he uses backfilling earth. The results make it possible to know what kinds of inputs are needed to make the soil fertile and thanks to this type of analysis we can also know if the fill soil is simply compatible with that of the vegetable garden.
Very useful for planning vegetable crops, analyzing the soil of a vegetable garden costs at least a hundred euros. The more samples and items to research, the higher the score. To reduce the cost of the operation, the gardener can carry out the coring himself on at least ten sampling points, 30 cm deep, and at different places on the plot on which he wishes to plant vegetables. All he then has to do is send his samples to the laboratory he has chosen.
Deficiency in the vegetable garden: solutions to improve the soil
A plant can suffer as much from a lack of essential elements only one excess. This is why the gardener has every interest in being on the lookout for the slightest symptom so as not to allow an imbalance at soil level to persist. For this, this growing medium must be as balanced as possible.
If the lack of water is quickly and easily identifiable, this is not the case for the deficiency in trace and macro elements, especially when you take your first steps in gardening. Hence the importance of being able to quickly spot the signs of failure because any soil improvement has a beneficial impact that is quickly visible.
For example, the simple fact of make up for a deficiency in nitrogen, phosphorus or potassium, namely the three major chemical elements of the soil, we can very quickly realize that this changes everything. Nitrogen promotes the development of foliage and more generally of all aerial parts of a plant. Of the plants that do not grow may therefore suffer from a nitrogen deficiency. Phosphorus is essential for beautiful flowering and abundant production, but it also participates in the development of the root system. A lack of phosphorus leads to low harvest.
As for potassium, it promotes the assimilation of nutrients and intervenes in the process of regulating the circulation of sap. The flowers of the plants are thus more colorful, the plants are more resistant to diseases, the fruits and vegetables see their taste qualities improved.
But be careful of the inappropriate amendments, excessive, or even carried out at the wrong time or with poor quality fertilizer products. The gardener should give preference to natural fertilizer products and always ask a professional if your plants show questionable symptoms rather than trying at all costs to correct the soil of your vegetable garden in the wrong way.