Efficient quality management systems

Quality has always been a top priority at Zelta Zeme
Certificated laboratory in company facilities

Company owns complete quality control laboratory. Yes, it is expensive, time consuming to proceed each test and really difficult to follow all specified testing points. But in result every cubic meter of product that leaves our factory complies with highest quality standards for peat moss raw materials and ready to use substrates.

To comply with chemical standards, our products are sampled and analyzed for pH, EC and S.M.E. analysis.

Procedures divided into 3 main areas: chemical, physical and packaging.

Testing started with sample obtaining. We run randomly  pick up  a samples from 6 different places, tests in order to evaluate our products’ real properties.


Start the test procedure with sample taking

Water holding capacity, air porosity and bulk density

Quality control procedures developed regularly to increase the quality of our products.

To assure that physical standards, we analyze particle size distribution, air %, porosity and moisture content.


Physical testingstructure and composition

Testing like in pharmacy, everything is doing “lege artis”

The following tests identify one of the most important substrate parameters that professional growers need to know


Chemical testing – Salt level and pH-value

Commercial value testing

How many pots will filled with one bag?



RHP quality mark for horticultural substrates

Substrates by Zelta Zeme benefit from the RHP quality scheme, which sets the strictest technical and qualitative standards (chemical, physical and phytosanitary) for growing medium:

– ensures full process and product control by external auditors and laboratories– controls peat bog management– lays down strict guidelines for harvesting, storage, monitoring of temperatures and treatment of peat raw material

– requires laboratory tests of all raw materials before their use– requires inspection of all substrates when ready to use

– all additives (e. g. fertilisers, wetting agents) and constituents need RHP approval– retained sample of each delivery to be stored under specific conditions

– specific RHP developed standards and methods (e. g. water uptake characteristic WOK, press pot stability, respiration method, potting density …)

– chemical and physical specification of each particular recipe to be predefined (ensuring maximum homogeneity of each delivery

ZELTA ZEME PEAT MOSS GROWING MEDIUM – subject to strict controls

Zelta Zeme is constantly working on its processes to condition, harvest and manufacture its sphagnum peat moss.

Certified raw materials for substrates. All of them are tested for suitability before their use in substrate production accordingly with internationally recognised guidelines of RHP (Regeling Handels Potgronden, www.rhp.nl)

Zelta Zeme fully control qualities are what makes peat moss a unique product in horticulture:

  • It improves growing medium structure, increases water retention and helps to reduce the leaching of nutrients. Peat moss can retain up to 20 times its weight in water.
  • It aerates and improve drainage of soils, allowing roots to breathe, grow and better absorb nutrients.
  • It improves soil buffering capacity because peat moss is highly tolerant to pH variations.
  • It improves the cation exchange capacity (CEC) that helps to retain minerals, releasing them over time and preventing the leaching of fertilizers.
  • It is a natural resource free of weeds and pollutants.

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