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Foliar fertilizing – the perfect complement to soil fertilizing

Our cultivated plants take in the basic nutrients they need through their roots. Even when all of the nutrients are present in our soil at a sufficient level, plants are not always able to absorb enough of them to meet their needs.
The make-up of nutrients varies greatly according to the soil type. Unfavorable climatic conditions such as dryness, wetness, low temperatures, etc., can have a detrimental effect on nutrient absorption.
Other factors can be of a biological nature, such as a poorly developed root system, strong growth, the wrong combination of plant and soil in fruit trees, replanting problems, etc.
If just one of the 17 essential plant nutrients is not available at an adequate level, the entire development of the plant is disturbed, and it becomes more vulnerable to disease and pests. In such situations, a quick solution can be to provide individual nutrients to the plant via its leaves.
Plants can absorb not only gaseous compounds such as oxygen and carbon dioxide through their leaves, but also mineral nutrients such as _calcium, _magnesium, _iron, _manganese, _zinc, _boron, etc.
This method of absorption is particularly effective because some loss of nutrients usually occurs in the case of administration through the soil. Compared to soil fertilizing, foliar fertilizing generally achieves the same effect with much smaller doses of nutrients – and significantly faster.
Absorption of nutrients through leaves
Plants can absorb mineral nutrients through their leaves that are dissolved in water or micronized. There are therefore several potential formulations for foliar fertilizers. Nutrients dissolved in water, usually salts, can, under ideal conditions, be almost completely absorbed and introduced into the plant’s metabolism within a matter of hours. Nutrients from _micronized particles applied to the surface of the leaf take slightly more time to be absorbed by the plant, and can therefore be applied in higher concentrations without causing undesirable side-effects (damage) such as calcium chloride “burns.” This damage is caused by an excessively high concentration of ions on the leaf surface, and their need to “liquefy.” After drying has taken place, the salts take water from the plant, damaging the entire cell structure.
LANXESS Distribution therefore provides two product lines:
1. Fertilizers dissolved in water based on carboxylic acids - CARBO products 
An auxiliary substance is required to dissolve mineral plant nutrients in water. Instead of chelates, chlorides, sulfates or nitrates, our _CARBO products contain carboxylic acids. Carboxylic acids occur in plants in a wide range of forms. Examples include formic acid, malic acid, butyric acid, tartaric acid, citric acid and acetic acid. The molecules of carboxylic acids contain carboxyl groups (-COOH), whose negative charge enables them to combine with positively charged nutrient ions such as _potassium, _iron, etc. in a special, water-soluble form. They also stimulate growth, the vitality of the culture and the quality of the end crop.
All CARBO products are readily absorbed by plants, not at all harmful to them, and can be mixed with other water-based products without difficulty.

2. Highly concentrated suspensions based on micronized rock flour
Natural raw materials, such as manganese carbonate, are ground so finely that the plant can absorb the nutrient in particle form directly through the leaf, primarily through the stomata. Formulated suspensions offer the great advantage that they can be very highly concentrated, which also means that the proportion of water in the formulations can be kept as low as necessary. This minimizes the spray rate per hectare. Being free of water-soluble salts, such suspensions are also very plant-friendly. This means that a single spraying can distribute large quantities of nutrients, as no phytotoxic effects are anticipated.
Timing foliar fertilizing perfectly - _leaf analyses tell you when
Symptoms of deficiency, typically reduced growth or discoloration of the leaves become clearly visible when the problem has reached a certain level of severity. That is the final warning that it is time to act! However, the majority of these symptoms will be irreversible by then. It is therefore much more advisable to prevent any kind of deficiency. This requires knowledge of local conditions (soil, climate, type of culture) and the nutrient requirements of the culture in its various stages of development. Leaf and/or fruit analyses - comparable to a blood test - are important tools in monitoring this. They enable nutrient deficiencies to be recognized quickly and clearly.
Evaluation is performed using a nutrient chart. This enables the immediate, targeted fertilizing of the cultivated plants with the nutrients required and can provide a long-term remedy.
To enable any necessary corrective fertilizing to be done in time, a leaf analysis should be performed as early as possible in the vegetation period. The following table provides an overview:
Sampling schedule for leaf analyses
Plant Development stage Sampling organ
Grapes When 10% of blossoms are open 30 - 50 leaves away from the inflorescence
Strawberries In fall or until blossoming starts Youngest, fully developed leaves
Pip fruits / stone fruits Beginning of June - mid-July Fully-grown rosettes of leaves from short shoots bearing fruit (approx. 200 leaves)
Another late leaf analysis between the end of July and August can provide valuable information for the coming harvest season, thereby influencing fall fertilizing. This is particularly the case with pome and stone fruits. This evaluates the 3rd and 5th leaves of the base long shoot.
Advantages of foliar fertilization after leaf analysis
  • Precise record of nutritional condition
  • Targeted application of the nutrients required instead of the “watering can principle” 
  • Possible at any time
  • Nutrients are absorbed directly into the plant
- The most economical and ecological solution!