Usage of PHOS4green Phosphate Fertilizers in Organic Farming

Organic suitability is not an utopian dream

PHOS4green consistently utilizes the cradle-to-cradle concept in line with the goals of organic farming. However, organic farming is faced with a dilemma: because phosphorus recycling products from sewage sludge or sewage sludge ashes are not yet approved for use, pure rock phosphate continues to be mined for use in such applications. However, the high energy required input for extracting, processing and transport from the countries of origin to the production facilities is anything but sustainable and goes against the goals of organic farming.

In addition, the quality of rock phosphate being extracted has decreased over time and is linked to damaging soil pH levels below 6, while the content of toxic heavy metals such as uranium and cadmium has increased meaning many fertilizers actually introduce heavy metals in to the soil.

Sewage sludge and sewage sludge ashes are also contaminated with pollutants and must be further treated before recirculation use. Compared with rock phosphate, the clean phosphorus recycled products produced from domestic sources have equivalent phosphate content, are almost free of pollutants and, unlike rock phosphate, enable targeted fertilization effect. In addition, the bioavailability of the recyclates can be adapted to different soil conditions, and the fertilizer granules can be applied in a much more targeted and economical manner. So far, only conventional farming has benefited from the purity and process quality; organic farming continues to wait for regulatory approval.

PHOS4green is one of the few ash-based processes that can be implemented on a large scale and solves both challenges: It makes the phosphorus highly available and at the same time significantly reduces the pollutant content in the end product. The final product is fertilizer-compliant, waste-free and does not contain ash residues.

We find that PHOS4green is highly suitable for organic farming due to:

  • the recovery/recycling of phosphate from a waste stream.
  • the elimination of long intercontinental transport routes – as is common in the production of conventional fertilizers – but the use of locally produced ashes
  • compliance with the limits for pollutants (see also heavy metal depletion) set out in the Fertilizer Ordinance – German Düngemittelverordnung (DüMV) and Regulation EG No. 2019/1009
  • the controlled fertilization of the soil due to defined phosphate content compared to direct application of sewage sludge

Glatt believes PHOS4green technology should be officially recognized as a process compliant with organic farming.