We only want the best for the perfect green space. We compare organic and mineral fertilizers and choose the best lawn fertilizer.
The decision on the right lawn fertilizer is important for the quality of the lawn [Photo: SIM ONE / Shutterstock.com]
Lawn fertilizers must meet the demanding requirements of the lawn and at the same time should be both user and environmentally friendly. Not only nutrient content and composition are important here. The speed and duration of the release as well as the release conditions also play a decisive role. The proportion and type of organic material contained have an influence on the fertilization effect and the long-term effect of fertilization on the soil. To what extent different lawn fertilizers meet the requirements, you will find out in this article.
Lawn fertilizers are available in mineral, organic, organic-mineral and organic-certified form. They meet the requirements to a different extent, which many lawn owners can hardly keep track of.
Organic lawn fertilizers in the test
Table of Contents
To make it easier for you to choose the right lawn fertilizer, we would like to discuss the pros and cons of various types of fertilizer for you below. We will start with organic lawn fertilizers.
Organic fertilizers are made from certain food waste, among other things [Photo: granata68 / Shutterstock.com]
Organic lawn fertilizers: origin
Organic lawn fertilizers are made from organic raw materials, usually waste. Various substances that occur in food and luxury food production are suitable for the production of fertilizers due to their nutrient composition and content. Vegetable recycling materials (such as vinasse, peel, flour from soy oil cake) can be used as well as animal waste (e.g. horn, blood, bones or feces).
Organic lawn fertilizers: properties
Organic lawn fertilizers have in common that they have a delayed effect. Therefore, they must be fertilized with foresight. Nutrients contained in the fertilizer are freed from their organic “packaging” by soil organisms so that they are available to the plants. They then provide nutrients when the weather is vigorous for the lawn, i.e. when there is sufficient moisture and warmth. This prevents the loss of nutrients due to leaching or outgassing. Due to the content of organic matter, they promote soil life, the soil structure and the humus content. It is the most natural way of fertilizing.
The promotion of soil quality ensures a healthy and resilient lawn [Photo: philmillster / Shutterstock.com]
However, the nutrient contents differ depending on the raw materials used. Much animal waste is rich in phosphate and nitrogen but poor in potassium, while that from faeces and vegetable matter does not have this deficit. The total nutrient levels differ as well as the organic matter content. In lawn fertilizers, the raw materials are combined in such a way that the needs of the lawn are met. However, always make sure that the main nutritional element potassium is sufficiently high. This is urgently needed by the lawn both to regulate the water balance in summer and to increase frost tolerance in winter. Special autumn lawn fertilizers have a lower nitrogen and higher potassium content.
The method of processing determines the speed of release and the comfort of application: Finely ground fertilizers are converted quickly, but they generate dust, get stuck in clothing and have an unpleasantly strong smell. However, if the material is only roughly shredded, the fertilizing effect sets in later. The ground material is therefore often pressed in the form of pellets. These swell when they come into contact with water, disintegrate and are soon available to plants.
Summary: Organic lawn fertilizers in the test
- Organic lawn fertilizers have a delayed effect, are weather-dependent and are rarely washed out
- Organic lawn fertilizers promote soil quality: water and nutrients can be better stored and made available, root growth is promoted, resistance to diseases is strengthened and soil compaction is reduced
- Lawn fertilizers contain more nitrogen and less potassium than autumn lawn fertilizers in order to be able to optimally meet the needs of the plants at the given time of the year
- Coarsely ground fertilizers are converted more slowly than finely ground fertilizers. Pelleted fertilizers do not generate dust and can be easily applied
Organic fertilizers can take several forms; if they are pelletized it is very easy to spread them [Photo: DGSHUT / Shutterstock.com]
Advantages and disadvantages of organic lawn fertilizers
For a better overview, you will find a table below with all the advantages and disadvantages of organic lawn fertilizers.
|Production is based on recycling and saves resources and energy||Animal raw materials often have an unpleasant odor|
|Stimulating the soil life leads to effective nutrient utilization||Delayed effect requires predictive fertilization by the user, about a month before it is needed|
|Soil life and organic content ensure improved soil quality||Nutrient content lower than with mineral fertilizers, overall larger amounts have to be distributed|
|Over-fertilization and leaching are avoided through natural implementation, and even lawn growth is promoted||The price per fertilized area is often higher|
|Natural long-term effect reduces the amount of fertilizer used and ensures even lawn growth||Weather-dependent release can lead to nutrient deficiencies in cool springs and to low levels of leaching in warm autumns|
|Soil chemistry and soil life remain in balance|
|Contain the important trace elements|
|Avoidance of time-consuming measures to improve the soil: aeration, scarifying and sanding are less necessary in the long term|
As you can see, the benefits of organic fertilizers outweigh the overall benefits. The higher price is usually justified, after all, not only the plants but also the soil are cared for. The leaching, noted as a disadvantage, occurs much more frequently and to a greater extent with mineral lawn fertilizers. You can find more information about the properties and use of organic lawn fertilizers in our special article.
Mineral lawn fertilizers in the test
Now that we have dealt with organic lawn fertilizers, the following is an overview of the advantages and disadvantages of mineral lawn fertilizers.
Mineral lawn fertilizers: origin
Mineral lawn fertilizers are made from fossil raw materials or – in the case of nitrogen – synthesized from atmospheric nitrogen. Both processes require a lot of energy and are not sustainable: Instead of recycling the nutrient-rich waste that arises from the fertilized plant, new nutrients are broken down from storage facilities or produced artificially.
Mineral lawn fertilizers: properties
Mineral lawn fertilizers have in common that they work quickly and regardless of the weather. Since the nutrients are in their mineral salt form, they can be absorbed by plants immediately after being dissolved in water. Mineral lawn fertilizers do not contain any organic substance. A positive influence on the soil quality is therefore excluded. However, mineral nitrogen input stimulates the activity of nitrogen-converting soil bacteria. With purely mineral fertilization, this leads to the degradation of valuable humus and thus even lowers the quality of the soil. Because the natural conversion process is bypassed and no organic material gets into the soil, the soil ultimately becomes depleted of useful earthworms, fungi, insects and bacteria.
Beneficial organisms such as earthworms feel at home in loose soil with a lot of organic material [Photo: Dahlhaus Kniese / Shutterstock.com]
Differences in mineral lawn fertilizers can be seen in the release time, the risk of leaching and over-fertilization, the composition and the quality. Simple mineral lawn fertilizers and those with long-term effects are available. The long-term effect is often achieved by a kind of coating of the fertilizer salts and increases the price. However, it reduces the amount of fertilizer used, as a larger amount of fertilizer can be applied that lasts for several months. The release takes place depending on the soil moisture, with some products also on moisture and temperature, as specialized bacteria are involved. Associated with this is the tendency to wash out: If mineral lawn fertilizers are only released depending on the humidity, a heavy rain shower can wash considerable amounts out of the casing, where plants can no longer reach them. Incorrect fertilization can also lead to frost damage in damp winters if nutrients are released despite the cold and inhibited plant growth. If the nutrients are also released depending on the temperature, leaching and incorrect fertilization are less likely. You can learn more about slow release lawn fertilizers in this article.
With mineral fertilizers there is a higher risk of leaching [Photo: Singkham / Shutterstock.com]
Even with mineral lawn fertilizers, a distinction can be made between fertilizers for the warm vegetation period and autumn lawn fertilizers. In this case, too, the nitrogen and potassium content are crucial in order to meet the needs of the plants.
Big differences can also be seen in the quality: Cheap mineral fertilizers in particular can be contaminated with heavy metals such as cadmium, chromium and even uranium due to the use of inferior rock phosphates. Although there are limit values for these heavy metals, small amounts can also be absorbed by plant roots. They can also get back into the food cycle through composting.
Tip: The EU mainly imports high-quality rock phosphates, for example from Morocco and China. These are not heavily loaded with heavy metals. However, many countries with less financial resources have to make do with the inferior rock phosphate. In addition, the supplies of phosphate-containing minerals are limited and are expected to become scarce in a few decades. The estimates differ and are heavily dependent on future consumption and the possibilities of exploiting deposits that are difficult to access.
Summary: Mineral lawn fertilizers in the test
- Soil and soil life do not receive any care with mineral lawn fertilizers and can become impoverished in the long term. This has a negative effect on the quality of the lawn
- Mineral lawn fertilizers quickly provide plant-available nutrients. This happens – depending on the type of fertilizer – completely independent of moisture and weather, moisture-related or weather-dependent. In the case of a weather-dependent release, the risk of leaching and over-fertilization is lowest
- Mineral lawn fertilizers are available for the warm growing season and for autumn fertilization, which differ in their nitrogen and potassium content
- Mineral lawn fertilizers have different levels of heavy metals such as cadmium, chromium and even uranium. Unpolluted phosphates are more expensive and tend to be found in higher quality products
The soil can become impoverished when mineral fertilizers are used [Photo: SingjaiStock / Shutterstock.com]
Advantages and disadvantages of mineral lawn fertilizers
For a quick overview, you will find a table below with the advantages and disadvantages of mineral lawn fertilizers.
|Fast acting speed can be used to treat acute nutrient deficiencies||Artificial form of nutrient supply can bring not only soil life but also soil chemistry out of balance: changes in the pH value can result|
|Price can be lower, but then the quality is often inferior||Contamination of mineral phosphate fertilizers with heavy metals|
|High nutrient contents ensure that small amounts can be used, which further improves the price per area||Need-based fertilization is only possible with well-versed knowledge of plant needs and soil chemistry and should better be left to experts|
|The release of long-term fertilizers can be planned well and is also safe when used properly||Incorrect use can result in incorrect fertilization and environmental pollution through leaching|
|Without the input of organic material, the soil is depleted in humus in the long term and loses its quality, ie water retention capacity, nutrient storage, root penetration and aeration decrease|
As you can see, the disadvantages of mineral fertilization outweigh the disadvantages. The advantages mentioned must also be assessed critically: Acute nutrient deficiencies can also be avoided with regular lawn fertilization. The price is only lower in the short term than with organic fertilizers, if one includes the loss of soil quality. This ensures that the lawn has to be watered and cared for more laboriously. Scarifying or even aeration may also be necessary more frequently and wild herbs are favored and must be controlled. Some of them may even resort to a lawn fertilizer with a weed killer, which we have examined more closely for you in this article.
Fertilizing with mineral fertilizers can increase the occurrence of weeds [Photo: Simon Kadula / Shutterstock.com]
Conclusion: the best lawn fertilizer in comparison
Both organic and mineral lawn fertilizers have their disadvantages. In addition, however, organic-mineral lawn fertilizers and organic lawn fertilizers are also offered. Organic-mineral lawn fertilizers make it possible to protect the soil quality and soil life while at the same time providing good nutrient availability. Organic lawn fertilizers do the same, but they only contain those mineral components that can also be used in organic farming. They also contain a much higher organic content. This means that we pay attention to the sustainable use of valuable raw materials. The combination of organic and mineral components eliminates many of the disadvantages of the respective categories: We therefore consider combined organic lawn fertilizers to be the best way to keep a lawn healthy and well-groomed. Since a corresponding product was previously not available for sale, we have developed our Plantura organic lawn fertilizer and the Plantura organic autumn lawn fertilizer. Both maintain the lawn and soil equally. Because only animal-free and natural raw materials were used, their smell is not unpleasant.
You can find more information about various lawn fertilizers here. If you have any further questions about fertilizing lawns, you will find them in our overview article.