TASPO article – Required: degradable coated fertilizer coatings

Clear trend towards sustainable and environmentally friendly products.

The trend towards products that are as sustainable and environmentally friendly as possible was also clearly evident in the fertilizer sector at IPM 2024. The two main topics for manufacturers were the development of biodegradable coated fertilizer coatings and the increasing demand for organic fertilizers.

In demand: degradable coated fertilizer (CRF) coatings
Since the coatings of traditional depot/coated fertilizers are classified as microplastics, they have been criticized for many years. The EU Fertilising Products Regulation of 2019 therefore stipulates that the casings of depot fertilizers that have EU approval must be biodegradable from July 2026 onwards. Degradation must be 90% within four years of the fertilizer being used. What is new is that the REACH Regulation of September 2023 stipulates that this biodegradability of fertilizer coatings will also become a requirement at national level from October 2028 onwards.

However, the relevant test method for biodegradability is not yet known, and will only be defined and published next summer 2024. As a result, there are still no coated/depot fertilizers that demonstrably meet the legal requirements for the degradability of their coatings as such. However, various test methods already exist on which the EU criteria are likely to be based on. For example, these include the methods according to the ISO 17556 and ASTM-D 5988 standards.

Degradable depot fertilizers
The Dutch depot fertilizer manufacturer Mivena announced that the “Durable” casing of its depot fertilizer Grow-Cote (=Horti-Cote) has passed the ASTM-D 5988 test for biodegradability and that it therefore expected it to meet the EU requirements. As such, this would make it the only depot fertilizer currently on the market whose coating is proven to be biodegradable.

The other manufacturers of coated depot fertilizers are working flat out as well on biodegradable casings, with corresponding prototypes from Osmocote and Plantacote undergoing practical tests at several test facilities at the moment, including in trial stations in Ellerhoop and Bad Zwischenahn.

New depot fertilizers
ICL draws attention to the depot fertilizer Osmocote 5, the “fifth generation” of Osmocote products. Mivena offers Grow-Cote Plus High N 18-5-10+Sp as a new depot fertilizer, whose increased nitrogen content enables particularly good growth results to be achieved. Plantacote N. V. has recently added Plantacote Boron 1-6-0 (+12% boron) to its range – a specialty product for crops requiring boron. Trials are planned to test for which plant species this fertilizer is to be recommended. The Haifa Group reports great customer interest in its coated urea CoteN, which is interesting for balancing the nitrogen immobilization of peat-free substrates, for example.

Organic fertilizers
Hauert focuses primarily on organic fertilizers, as mineral products are not an option for many customers. In the municipal sector, for example, the cities of Munich, Zurich and Bern have decided to only use products with organic approval. This means that mineral fertilizers are no longer an option for them.

For lawns, DCM offers the organic-mineral fertilizer Liquid Green 8-0-4 (+2% Fe) with iron chelate, which displaces moss and – unlike fertilizers with iron sulphate – does not cause “rust stains” on stones.

For more even water absorption of base layers and substrates, DCM offers Intro 2.0, the first wetting agent with organic certification, which is required by more and more local authorities in addition to organic farms.

Methylene urea fertilizer
With Tardit 40, Hauert also has a new methylene urea fertilizer in its range, characterized by a particularly good nitrogen utilization rate of over 80% within three months.

Collagen fertilizer
The range of new organic nitrogen fertilizers from AVEMA, first presented at IPM 2023 a year ago, has been expanded: in addition to the slow-release fertilizer ODP N, the slightly faster-acting ODP NRK 2-4 and the even faster ODP NC 1-2 are now also available. The AVEMA ODP fertilizers consist of collagen fibers, a high-quality structural protein from the leather industry. They are easy to spread and have a low odor. In trials at the Weihenstephan University of Applied Sciences, they showed a very good N mineralization of 70%. Studies are currently being carried out at several teaching and research institutes to test the suitability of these fertilizers for various horticultural crops.

Heinrich Beltz
Landwirtschaftskammer Niedersachsen (Germany)
LVG Bad Zwischenahn