HEATHland-derived organic amendments for augmentation of soil C and reduction of PEAT-dependence in horticulture in Flanders (HEATH4PEAT)

Agricultural and horticultural soils often struggle with the so-called carbon-nitrogen paradox: decreasing carbon levels threaten soil quality, but strict nutrient legislation restricts the supply of carbon-rich organic matter that also contains and releases nitrogen and phosphorous. In the ornamental plant sector, too little soil carbon means lower soil fertility, resulting in poorer rooting among others. Available carbon sources also do not match specific ornamental plant cultivation requirements, because too much nitrogen is released in the first year of perennial cultivation. This research project is therefore looking for high-quality smart additives: materials that are composed in such a way that they have an increased efficiency of C input, and where the mineralization process (whether or not nitrogen is released) can be controlled as a function of the crop. At the same time, the project is also aimed at container cultivation: possible peat replacements can reduce the less desirable dependence on peat there.  Specifically, the researchers will focus on carbon-rich additives originating from heathland and forest areas, in particular chopper material.

We are expanding the knowledge base for the development of stable and high-quality aggregates. We carry out concrete product development in order to arrive at usable, qualitative and stable products for open field and container cultivation, with a controlled mineralization from a raw material as a function of time. We evaluate these products at farm level. We initiate the necessary professional networks by means of consultation moments, demonstration activities, study days, publications, etc. These objectives are achieved through collaboration between the knowledge institutions (KU Leuven, PCS, ILVO) and organisations and companies throughout the chain: land management authorities (as "producers" of the raw material: ANB, Natuurpunt, Inverde, Agrobeheercentrum Eco²), processing and product distribution companies (Kwanten en Co NV, Peltracom NV) and end users (Sylva, De Nolf, Boerenbond and AVBS).

For land management authorities, a sustainable market for the material from management works means reduced costs (they save on disposal). For the processing and distribution sector (potting soil companies, aggregate manufacturers, distributors) a new, well tested product generates added value and new employment opportunities. The dependence on peat decreases. For ornamental plant cultivation companies, this project results in an increased quality of the crops (root growth, disease resistance), a better soil condition, a lower risk of exceeding the nitrate standard, and reduced dependence on peat.