Organic fertiliser? Correct, these are horn shavings and horse manure, for example. These often supply mainly nitrogen and also have a soil-improving effect. Organic fertilising with the whole range of nutrients, on the other hand, is possible with organic complete and special fertilisers from the trade.
Organic fertilisation: Good sources of nitrogen
Let’s stick to manure for now. Horse droppings are an excellent feed for roses, and spreading them also improves the water retention capacity of the soil. You don’t necessarily have to order horse manure from the nearest stud farm – it has long been available dried, pelletised and neatly packaged in specialist shops (e.g. Hippo-Fert from Cuxin).
Cattle manure (e.g. MANNA Biorit) and chicken manure (e.g. naturpur) are also available in the trade. The latter contains not only nitrogen but also plenty of phosphorus. While the manure pellets can be worked into the soil immediately, the manure should be composted first, if possible, before spreading. Otherwise sensitive roots – especially of vegetable plants – will be damaged and “burnt”. During storage and composting, potential pathogens are also largely broken down.
However, berry bushes, roses and fruit trees can certainly be provided with some fresh manure in late autumn – as long as it is spread thinly.
One thing, however, cannot be achieved with manure pellets: For a so-called warm bed of leaves, dung, compost and soil, you need fresh dung from rabbits, chickens or horses. During the rotting process, heat is released so that early vegetables can be grown early.
Horn shavings also provide nitrogen and are natural – they are available ground as horn grit or horn meal (e.g. Naturabell from Compo). Horn shavings are slowly broken down in the soil by microorganisms, so that the nutrients are gradually released.
The finer the material is ground, the faster the nitrogen is available to plants. Horn shavings are very suitable as an annual gift for berry bushes, fruit trees, ornamental shrubs and perennials.
Organic fertilising with universal and special fertilisers
In addition to nitrogen-rich natural fertilisers, there are also universal and special fertilisers that are tailored to the nutrient requirements of specific crops, for example soft fruit, boxwood or herbs. They are available in both solid and liquid form.
They are made from animal or vegetable raw materials. They contain, for example, horn meal, feathers, guano (a phosphate-rich product from seabird droppings), mycorrhiza fungi and other microorganisms, algae extracts, molasses as a potassium supplier, fermented grape marc and mineral rock components such as kieserite or primary rock flour.
Still relatively new on the market are fertilisers for vegetarians that are made only from vegetable raw materials, e.g. phytograsses from maize grains (from Eco Bio Systems) or sugar beet molasses (Azet VeggieDünger from Neudorff).
Things to know about organic fertilisation
1) Organic, mineral? What is the difference?
Organic fertilisers are always of plant and/or animal origin and do not contain any degraded or synthetically produced nutrient salts. Important for the gardener: Organic plant food usually has a somewhat delayed effect, as the proportion of soluble salts is very low.
Only when soil organisms have degraded the ingredients do plant-available compounds emerge.
2) Is organic fertilisation always environmentally friendly?
Yes, if it is applied as needed, preferably according to the results of a soil analysis. Because like any other plant feed, it can harm plant growth if it is unbalanced. In addition, overfertilisation with nitrogen (e.g. from liquid manure, fresh manure) is usually accompanied by nitrate pollution of the groundwater. Ammonia, which is harmful to the environment and the climate, can also escape.
Do not work fresh manure into the soil in autumn. This is because there is a risk of nutrients leaching out of a fallow bed. Place manure on as small an area as possible in the shade and cover it with a tarp or soil.
3) Is a quick effect only possible with mineral fertilisers?
No, fast plant action is possible with, for example, organic liquid fertilisers to mix with the irrigation water, finely ground horn and plant slurry.
If you do not want to make your own liquid manure, you can use dry concentrates from the market. Compost and manure also contain quickly available ingredients.
4) Organic fertiliser – Are animal components always safe?
Manure should always be composted before spreading so that dangerous germs are killed. In addition, only use excreta from healthy animals. Litter and faeces from dogs and cats as well as from all other carnivorous animals should not be composted for hygienic reasons.
Use manure and manure pellets from organically reared animals, especially for vegetable crops, to avoid excessive pollution.
5) Is it true that potassium can only be given in mineral form?
No. However, many complete fertilisers were and are available as organic-mineral commercial products. The reasons for this are, on the one hand, the faster effectiveness of the mineral components,
on the other hand, potassium salts from potash mining are much cheaper and more readily available than, for example, vinasse, a waste product from sugar production, which contains nitrogen as well as potassium. Potassium is also contained in compost, dung or sheep’s wool. Pure rabbit dung and cattle manure contain relatively high amounts of potassium.
6) Organic fertilising – What fertilising effect does sheep’s wool have?
Hair is very similar to horn shavings in chemical composition. Since only part of the wool from sheep shearing is spun, it is available for insulating and fertilising purposes. It contains mainly nitrogen (approx. 11 %) and potassium (approx. 5 %).
In addition, sheep’s wool pellets are swellable, i.e. they can store water: advantageous especially on light soils. Products from grazing animals, such as sheep wool and sheep dung, are also considered to be low in medicines.
7) Is it possible to do without compost as fertiliser?
The nutrients contained in compost can be supplied by other means. But: compost is not only a fertiliser, but as a humus supplier also a soil care product. Its humic acids keep soil life fit and the crumbly soil structure stable. In addition, a high humus content increases the water and nutrient holding capacity of a soil.
8) How and when is organic fertiliser applied?
Since it takes effect slowly, it is applied one to two weeks earlier than the faster-acting mineral fertilisers. While mineral fertiliser is usually dissolved by the irrigation water and carried to the roots, its organic counterpart must be worked into the topsoil to become effective. For this it lasts up to six months, well-rotted compost and manure even for years, because part of the nutrients it contains is mineralised only very slowly.
After years of regular compost applications, complete fertiliser applications are often unnecessary or can be reduced. Sometimes only individual nutrients need to be supplemented. It is therefore best to commission a soil analysis every two to three years before the start of the season and fertilise specifically according to the results. This is the perfect way to fertilise organically.