The organic fertilizer hides a complex product that activates various soil processes. Although remedies are commercially available, everyone should think about making their own. This is neither difficult nor expensive, because plants form the basis of a good fertilizer.

Organic fertilizer is the most environmentally friendly fertilizer option

Table of Contents

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  1. the essentials in brief
  2. definition
  3. mode and speed of action
  4. application
  5. Be careful when buying
  6. advantages and disadvantages
  7. make your own fertilizer
  8. frequently asked Questions

    9. the essentials in brief

    • Organic fertilizer consists of animal or plant residues. The nutrient composition varies depending on the origin of the biodegradable substances.
    • Compared to mineral fertilizers, they act more slowly. Organic NPK fertilizers contain both natural and synthetic substances.
    • Organic fertilizers are incorporated into the soil and are only suitable for lawns in liquid form. When buying, aspects such as quality, purpose and origin should be considered.
    • Since the pros outweigh the cons, natural fertilizers are a better choice. They can easily be made by yourself.

    What is organic fertilizer?

    If a fertilizer is of organic origin, then dead organisms and their excrement provide the fertilizing components. They are made from waste from agriculture or private horticulture. The nutrients are not available in pure form, but are mostly bound to carbon-containing compounds.

    These are organic fertilizers:

    • Slurry, liquid manure or stable manure
    • sewage sludge
    • green manure
    • compost and straw

    Nutrient content of organic fertilizers

    Organic fertilizers are rich in essential nutrients and life

    Organic fertilizers contain the main nutrients nitrogen, phosphorus and potassium (NPK for short) and a number of other trace elements, proteins and vitamins. Nitrogen comes in different forms. The total nitrogen content includes the organically bound nitrogen, which has to be decomposed by soil organisms, as well as immediately available nitrogen compounds such as ammonium nitrogen. These compounds are available to plants in the first year. The nutrient content varies depending on the substrate.

    nitrogen content effective nitrogen percentage in the first year phosphorus content potassium content
    Compost from leaves and green waste 6kg/t less than 1kg/t 2kg/t 4kg/t
    horse manure 4kg/t 2kg/t 3kg/t 11kg/t
    horn shavings 140 kg/t 1kg/t 8 kg/t 1kg/t
    organic waste 9kg/t less than 1kg/t 5kg/t 8 kg/t
    bark mulch 3kg/t insignificant less than 1kg/t 1kg/t

    How does organic fertilizer work?

    The composition of the material determines how quickly the organic fertilizer works. The C/N ratio is the ratio between carbon and nitrogen and provides an orientation for the rate of action. The more organically bound nitrogen it contains, the slower the fertilizer works. This must be mineralized in the soil, which first releases ammonium compounds and finally nitrate.

    Plants can absorb nitrate. Conversely, this means that the fertilizer works faster the more nitrate and ammonium nitrogen it contains. Manure is an example of a particularly fast-acting organic fertilizer. It resembles a dissolved mineral fertilizer.

    Ammoniacal nitrogen content in:

    • slurry: about 50 percent
    • stable dung: ten to twenty percent
    • compost: around five percent

    background

    mineralization and humification

    Various processes take place when microorganisms utilize organic material. The decomposition of organic matter in soil is called humification. The plant and animal remains are not broken down, but broken down and transformed by soil organisms. This produces humic substances, which form the basis of humus. These organic fragments are broken down by enzymes from various microorganisms and finally decomposed. This results in mineral end products that can be used by the plants. This process is called mineralization.

    Influencing Factors

    The implementation of organic fertilizer depends on the weather, because the active soil organisms are strongly influenced by their environment. A moist environment with warm temperatures and good oxygen supply promotes the conversion of the material. Cold, wet and lack of oxygen inhibit the activity of the soil fauna.

    Organic NPK fertilizer

    Organic fertilizers can also be industrially processed to contain natural substances and synthetic nutrients. They are less concentrated than mineral NPK fertilizers and can be applied in liquid form or as granules. With regular use, the soil is improved because organic commercial fertilizers build up the humus layer. On the one hand, they contain nutrients that act immediately and components that release nutrients over a longer period of time.

    This is what organic commercial fertilizers contain:

    • animal origin: Meals made from animal skeleton parts such as meat bones and horn; hair meal pellets, feather meal
    • vegetable origin: Water and concentrates from potato plants, leftovers from corn processing, vinasse, malt germ
    • other organic NPK fertilizers: Biosol, fertilizer for legumes, hydrolysates

    application

    Organic fertilizers need to be incorporated lightly into the top layer of soil in order to have their full effect. Microorganisms attack the components from all sides and decompose them so that the nutrients are made available to plants. In the case of a superficial distribution, it is mainly the nitrogen content that is broken down. The material should also not be worked in too deeply, as the absence of air will lead to rotting processes.

    Organic fertilizer for lawns

    Organic fertilizer is also a good choice for the lawn

    The nutrient supply via organic fertilizers can not only be used for herbs in the bed. They also provide the lawn with vital substances so that it thrives magnificently. However, solid substrate is not suitable for fertilizing an existing lawn. In this case, liquid alternatives are necessary because compost can no longer be worked into the soil. Organic commercial fertilizers in liquid form are still better than mineral fertilizers.

    organic lawn fertilizers mineral lawn fertilizers
    humus layer promote the formation of hummus Decomposition of humus when used excessively
    ground activity Soil creatures are encouraged reduce the diversity of soil fauna
    casting time long-term effect quick and direct effect
    application compost only in front of the lawn; organic liquid fertilizer on overgrown areas three times a year on overgrown areas
    Others often polluted by heavy metals or pesticide residues enriched with weed-inhibiting additives

    Buy organic fertilizer - what to look out for?

    Laboratory tests have found heavy metals, pollutants and pesticides in organic fertilizers from various price ranges. A sample from the magazine "Öko-Test" (read the July 2022 issue) states that even most organic products are not perfect. If you want to buy organic fertilizer, you should know exactly where it comes from.

    Even organic fertilizers are not perfect. They can contain pollutants and heavy metals.

    Soil fertilizer or plant fertilizer?

    Fertilizers that are suitable for soils mainly contain stable carbon compounds that are broken down over a longer period of time. They increase soil fertility slowly and sustainably because they act as long-term fertilizers. Mineral fertilizers are completely out of the question as soil fertilisers, as they have a short-term effect and the nutrients are washed out. The situation is different in the group of plant fertilizers. Organic NPK fertilizers provide immediately available nutrients and offer long-term active substances. In contrast to mineral products, they increase the crumb structure.

    Tips for decision making:

    • Granules and pellets can be distributed better and do not create dust
    • Substrates from composting plants are inexpensive and have an optimal nutrient composition
    • Group plants with similar needs and choose an appropriate fertilizer accordingly

    Vegetable or animal?

    Manure usually smells very strong

    Organic fertilizers are waste products and therefore the optimal choice in terms of sustainability. If the degradable residues come from plant raw materials, they often provide better nutrient mixtures than animal products. The production of vegetable raw materials requires little space and requires less water. When it comes to fertilizers made from animal residues, it is often not clear whether the raw materials come from organic or conventional animal husbandry. The odor nuisance is greater with ground animal residues than with purely vegetable products.

    tips

    Coffee grounds are a true source of nitrogen and free from animal products.

    Organic fertilizer - advantages and disadvantages

    Natural fertilizers based on plant or animal residues improve the structure of the soil and promote humus formation. Due to their slower action time, the nutrients in organic fertilizers are not washed out as quickly as in mineral alternatives. They provide the crops with nutrients over a long period of time without over-fertilizing the soil. Plants receive sufficient nutrients during their main growth phase, because the soil organisms are more active during this time than in the cold months.

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    Disadvantage:

    • Fertilizer requirements are difficult to calculate in advance
    • not suitable for remedying an acute nutrient deficiency
    • animal products often only contain one or two main nutrients

    From an ecological point of view

    In many soils there is already an excess of nitrogen, which puts a heavy strain on sensitive habitats. This imbalance means that certain plant species are pushed back and only those that primarily need nitrogen to grow dominate. By fertilizing with organic substances from your own garden, no new nitrogen is introduced into the ecosystem. A balanced cycle is created in which nutrients are returned.

    Make your own organic fertilizer

    Plant manure is a great fertilizer

    Compost is considered an all-rounder among natural fertilizers. The substrate provides the plants with calcium, phosphorus, magnesium and potassium. Weak-feeding plants thrive if they get some compost from time to time. But even heavy feeders grow better with regular composting.

    tips

    Herbs with large and soft leaves enjoy a long-term fertilizer. Sheep's wool pellets are ideal for potted plants.

    vegetable manure

    Collect wild herbs such as stinging nettles, tomatoes, yarrow and comfrey and roughly chop the plant parts. Put the material in a bucket and fill it up with water until all parts of the plant are covered. Cover the jar with a cloth and stir the batch every two to three days.

    The liquid manure is ready after about two weeks. No more bubbles should appear when stirring, because gas bubbles indicate ongoing activity of microorganisms. During the fermentation process, various nutrients are released from the plant parts. Plant manure is rich in silicic acid and trace elements.

    • Rock flour (€14.13) or algae lime suppress unpleasant odours
    • Plant manure is suitable for heavy feeders such as tomatoes and potatoes
    • Use in a five to tenfold dilution with rainwater

    green manure

    If beds lie fallow and will only be used again in the coming season, you can use them for a fertility-enhancing cover crop. Pay attention to relationships, because species from the same family should not grow one after the other on the same bed. Shortly before seed formation, the beds are mown, leaving the plant material on the surface. Green manure loosens the soil. At the same time, weeds are suppressed and the soil is protected from erosion and leaching.

    Suitable seeds

    Mustard is ideal for green manure

    Sow yellow mustard in areas that will not subsequently be planted with cabbage or cruciferous vegetables. The fast-growing yellow mustard is ideal as a preceding crop for potatoes. The blue-flowering phacelia is not closely related to any type of vegetable and can therefore be sown universally. Legumes such as clover, lupine, vetch or winter peas are ideal nitrogen suppliers.

    frequently asked Questions

    Which fertilizer is suitable for which plant?

    A nitrogen-rich fertilizer is the typical green manure. It is suitable for all plants that should develop healthy foliage. Horn shavings (€32.93) and coffee grounds are ideal nitrogen suppliers for lawns, cabbage and lettuce or indoor plants. On the other hand, a phosphorous fertilizer is ideal for flowering plants, because this nutrient promotes the development of flowers and fruit. Supply flower bulbs, violets and fruit trees with manure from chickens and poultry.

    Why are organic fertilizers better for crops?

    Potatoes, zucchini and cabbage are among the heavy feeders that need a lot of nutrients throughout the growth phase. Chemical products act immediately, so the plants are often over-fertilized. The excess nutrients are quickly washed away by rain, resulting in a nutrient deficiency. Organic fertilizers feed the plants evenly over a long period of time.

    What are the signs of incorrect application of mineral fertilizers?

    When using mineral fertilizers, you can often see the effects of improper use. The nutrients are in the form of water-soluble salts. The salt extracts water from the plant cells, which is why the plants often let their leaves droop after fertilization. In order to reduce the salt content in the substrate, extensive watering is necessary.

    Can organic fertilizers be used incorrectly?

    Natural fertilizers should also be applied with caution, because incorrect nutrient additions quickly lead to deficiency symptoms or unbalanced plant growth. If the phosphate content is too high, other nutrients can no longer be absorbed. An oversupply of nitrogen causes vigorous leaf development, which stagnates flowering.

    Does soil pH matter when using organic fertilizers?

    Nutrient-poor sandy soils need more nutrients than humus-rich subsoil. However, even after increased fertilizer application, plant growth can stagnate. If that's the case, you should check the soil pH. Plants can no longer absorb many nutrients if the pH is too high. In this case, the soil should be treated with acidic substrates before fertilizing. If the pH value is in the acidic range, the plants can hardly absorb any nitrogen. Liming improves the soil.

Category:

Vegetable garden