The Content Of The Article:
- Causes of over-fertilization
- The long way from dung to chemical fertilizer
- Over-fertilization and deficiency go hand in hand
- Signs and consequences for plants
It is a complex nutrient dynamics that takes place in the system of the garden floor. A healthy growth of plants depends on a balanced balance of main nutrients, such as nitrogen, phosphorus and potassium as well as numerous trace elements. Unfortunately, the symptoms are similar to deficiency symptoms and excess nutrients. Is fertilized according to the motto, 'much helps a lot' tilts a shortage only in the other direction, without it comes to a solution. Instead, prudence is needed. Read here how the over-fertilization of the soil affects with information on signs and consequences for the plants.
Causes of over-fertilizationIt is an indisputable fact that the soils in most ornamental and vegetable gardens are over-fertilized. This applies both in the private and in the commercial sector, with fatal consequences for our health and the environment. The question of the cause is difficult to answer in one sentence and requires a retrospective view of the historical development.
The long way from dung to chemical fertilizerFor plants to flourish, good soil, enough water, air and sunlight are not enough. Only a balanced combination of nutrients and trace elements ensures a vital, healthy growth. Where the availability of nitrogen, phosphorus, potassium, and other minerals is limited, the entire ecosystem suffers, and entire cultures perished throughout history. Since the invention of agriculture farmers and gardeners are trying to counteract a lack of nutrients. Until the 19th century, soil fertility was promoted using organic fertilizers such as bone meal, manure and horse manure. In addition, methods were used, such as crop rotation, supplemented by optimized equipment and machinery. In fact, steadily higher yields were achieved, so that despite growing populations, enough food was available.
This development changed dramatically around 1840, when Justus von Liebig came on the scene. In his opinion, it was perfectly sufficient to supply the soil with sufficient inorganic nutrients to promote plant growth at will. Unimagined earnings increases were now within reach. Near-natural methods, such as crop rotation and the use of organic fertilizers were suddenly no longer considered modern enough. Instead, a development began, at the end of the invention of the chemical fertilizer stood. Hundreds of tons of industrial fertilizer are released into the environment every year, most of which go unused into deeper soil layers, into groundwater and drinking water, into biotopes and through outgassing into the air. The consequences are known to us all under catchwords such as 'acid rain', 'biodiversity loss', 'water tipping over' or 'greenhouse effect'. Although the use of blue-grain, dicamba and other purely chemical fertilizers is increasingly becoming twilight, it continues to take place privately and primarily in commercial cultivation.
Over-fertilization and deficiency go hand in handIn view of the described development now simply stop any fertilization, proves to be a fallacy. In fact, a nutrient oversupply is always accompanied by a lack of other minerals. If a plant lacks nitrogen, it will not be helped by an oversupply of potassium. On the contrary, a surplus of certain substances reinforces the undersupply. A classic example is the excess of lime in the soil on plants that require an acidic pH. The excess of lime blocks the path of iron into the plant pathways, which by nature is sufficiently abundant in the soil. The result is life-threatening leaf chlorosis. In order to save the affected plant, the over-fertilization with lime is to be revised and at the same train immediately available iron to administer.
Signs and consequences for plantsThe optimal nutrient supply of ornamental and useful plants is therefore one of the central challenges in the hobby garden. An important step on the way there is the correct interpretation of the signs of over-fertilization of the soil to take appropriate action. For your guidance, we have listed some typical symptoms for you below, including hints on the consequences for the plants and tips for correcting the problem:
- Soft, spongy shoots
- Reinforced growth in length
- Soft leaves that turn blue-green or fade
- Later rolled down leaf margins
- On potted flowers, the lower leaves turn yellow with brown edges
- Increased frost sensitivity
- Increased infestation with pests, especially aphids, spider mites, cicadas
- Increased occurrence of fungal infections, such as mildew, gray mold and stipe rot
- Increased susceptibility of rubber flow to stone fruit
- Reduced shelf life of fruits and vegetables
Tips: Consistent mulching with straw in the long term contributes to the elimination of over-fertilization with nitrogen, as the straw attracts and binds the nutrient. The administration of the plant strengthening agent Mr. Evergreen Flora also provides relief. In addition, the family members of the genus Phaecila - also known as honey bees - remove the harmful nitrate from the soil; seeded as green manure on the over-fertilized area.
Phosphorus eutrophicationSigns and consequences
Excessive intake of this nutrient does not cause immediate symptoms, such as nitrogen. Rather, too much phosphorus indirectly affects. It comes to an overall growth disorders, as important trace elements such as copper and iron can no longer be absorbed by the plant. If you suspect an over-fertilization with phosphate, only a professional soil analysis from the special laboratory will give more detailed information.
Tip: One of the main causes of phosphorus over-fertilization is the overuse of blue-grain. In addition, the concentrated administration of bone meal is responsible for the shortcoming. Therefore, adjust the nutrient supply to a phosphate-poor, mineral-organic fertilizer and no longer use bone meal.
- leaf-edge necrosis
- root burns
- leaf damage
- stunted growth
- Growth inhibition due to decreased absorption of calcium and magnesium
- Destruction of the fine crumb structure in the soil due to the displacement of calcium ions
Over-fertilization of the soil with potassium rarely causes serious consequences for the plants. Due to its mobility, potassium is easily washed out by rain and irrigation. In addition, only the potassium is available to the plants, which accumulates on the outer layers of the clay minerals in the soil, while the ions between the layers can not be absorbed. The more clay-rich the soil, the lower the risk of potassium oversupply.
Tips: In very light, clay-poor soils, it pays to invest in a low-cost Primus Kalitest from Neudorff before taking any action against over-fertilization with potassium. If your suspicions are confirmed, we recommend repeating potassium-poor, magnesium-stressed rock flour repeatedly.
Calcium eutrophicationSigns and consequences
- A pH greater than 8
- Yellow-green leaf discolorations
- Lime-encrusted soil
- leaf fall
Tips: The regular administration of acid leaf compost makes an effective contribution to the elimination of excess lime in the soil. In addition, from now on no hard tap water should be used, but only soft rain or pond water. Lowering the pH also affects the incorporation of peat.
Magnesium eutrophicationSigns and consequences
Diagnosing magnesium over-fertilization is difficult even for the expert as there are no immediate symptoms. First and foremost, the closely related interaction between magnesium and calcium is out of balance. The oversupply of magnesium blocks the availability of lime, so again we are dealing with a typical after-effect. The result is damage to the roots of those plants that rely on adequate lime intake. At the same time, too much magnesium inhibits the plant's access to the main nutrient, potassium, which primarily affects frost resistance.
Tips: As the practice has proven, magnesium over-fertilization usually indicates an oversupply of the soil with other nutrients and trace elements. The administration of magnesium-enriched fertilizers should be discontinued from now on, so that the problem is regulated by leaching over the next few years. The incorporation of 3 liters of compost per square meter of garden soil completely covers the nutrient requirement during this phase.
Extensive use of industrial fertilizers has led to an oversupply of nutrients, which runs counter to the ultimate goal of improved plant growth.In addition to the disastrous consequences for the environment and health, the over-fertilization of the soil paradoxically causes at the same time a reduced growth and other, typical deficiency symptoms. Without further ado, any use of fertilizer is therefore no solution. Rather, conclusions should be drawn from the recognizable symptoms on the ideal composition of the nutrient supply in the hobby garden. The signs listed here may serve as a guide to minimizing the negative consequences on your plants and reversing them with the help of our tips.