Although calcium cyanamide fertilizer is harmful to he alth, it is still used. We explain the disadvantages of fertilizer and show alternatives.
Calcaneous nitrogen combines the fertilization of nitrogen with the liming of the soil and a broad control of harmful organisms. What seems sensible at first glance and is advertised as such by distributors of the fertilizer veteran, however, as we will show you, also has some significant disadvantages.
What is calcium cyanamide fertilizer?
The chemical name of calcium cyanamide is calcium cyanamide (CaNCN or CaCN2). The dirty grey-black powder or granules have been produced for over 100 years by binding atmospheric nitrogen to calcium carbide at high temperatures and with high energy consumption. 19.8% of the substance is nitrogen, 60% calcium oxide, the rest is carbon and often impurities such as iron and aluminum. Because calcium cyanamide brings in not only nitrogen but also lime and also has a herbicidal, bactericidal and fungicidal effect, it can be described as a multifunctional nitrogen fertilizer.
How does calcium cyanamide fertilizer work?
Calcaneous nitrogen is activated in soil when it comes into contact with liquid water. The reaction also takes place at cool temperatures. In the following we distinguish three different effects of calcium cyanamide fertilizer.
Lime effect
Calcium hydroxide (slaked lime) is formed, which is easily soluble and can quickly raise the pH value of the soil or be absorbed by plants. A third of the lime contained is present in slower-acting forms of lime. Liming the top layer of soil improves soil structure, ensures stable crumbs, better aeration and water absorption of the soil, and also stimulates soil respiration. The pH of the soil is raised. The lime effect corresponds to 60% CaO, so calcium cyanamide can be treated like lime with 60 grams of calcium oxide in 100 grams.
Nitrogen Effect
After dissolution, the nitrogen is present as cyanamide (H2CN2). After a few days, this is converted into urea and - to a lesser extent - dicyandiamide (DCD). While urea soon becomes plant-available ammonium and nitrate, DCD remains in the soil longer without being converted. In this way, a long-term effect is achieved and the fertilized nitrogen is less at risk of being washed out.
Hygiene effect
Cyanamid acts in the upper three to four centimeters of the soil against many weeds and their seeds, against slugs, wireworms and numerous soil-borne fungi, such as plasmodia, i.e. unicellular parasites of clubroot (Plasmodiophora brassicae ). However, this effect is temporary because the cyanamide continues to be converted.
Disadvantages of calcium cyanamide fertilizer
2016, an opinion by the EU he alth authority determined that calcium cyanamide can damage human he alth and contaminate surface and ground water. This applies both to the application methods recommended by the manufacturers and to the improved application methods. In addition, the intake of cyanamide - for example as dust - can lead to so-called calcium cyanamide disease: The cyanamide inhibits acetaldehyde dehydrogenase, which is responsible for breaking down acetaldehyde in the blood. Acetaldehyde is a breakdown product of ethanol (drinking alcohol) and causes dizziness, nausea and hot flashes. So if alcohol is consumed after ingesting cyanamide, even small amounts can result in an unbelievably bad, long-lasting hangover, as the acetaldehyde accumulates in the blood. However, when used properly - especially by wearing a face mask - a sufficiently large intake of cyanamide is prevented. Because calcium cyanamide fertilizer is corrosive, gloves should be worn when applying.
The versatile nitrogen fertilizer has even more disadvantages: It has a strong humus-consuming effect because it rapidly stimulates bacterial soil life for a few weeks by increasing the pH value. These organisms consume large amounts of carbon for energy. However, because calcium cyanamide does not provide any organic, carbon-rich material as a substrate, the bacteria attack the soil's own carbon, the humus. At the same time, fungi, which are also extremely important soil-formers, are damaged by the sudden increase in pH. Since various mushrooms insymbiosis with our plants, that cannot be an advantage for us. And of course there is the biocidal effect of cyanamide in addition to this effect: Of course, this does not distinguish between harmful and beneficial bacteria, fungi and plants - like a chemical club, it makes a wide breach in soil life.
Alternatives to calcium cyanamide fertilisers
The nitrogen requirement of soil is covered in a much more resource-saving, natural and soil-friendly manner with the help of primarily organic fertilizers - such as our Plantura organic fertilizers. However, if you absolutely want to use calcium cyanamide - for example to avoid having to dispose of old stocks - we urgently recommend determining the pH value of your soil beforehand so that it does not become too high for plants to tolerate. The parallel incorporation of stable organic material such as straw, bark humus or bark mulch helps to protect the humus in the soil. An alternative to the broad biocidal effect of calcium cyanamide is the targeted control and sometimes the benevolent tolerance of organisms that do not necessarily bring us a direct benefit in the home garden, but which invariably have an ecological benefit.
You can find more information about our environmentally friendly Plantura organic fertilizers here.