"Strawberry cultivation in Belgium is facing strict governmental controls by the entities VLM and VMM. Both in the soil as in water regularly norms of nitrogen content are exceeded. Soil cultivations of vegetables and also strawberries are proven to cause run-off of nitrogen-rich water and also raises the nitrogen content in the soil. European legislation demands of the member states to respect the norms. Belgium strives towards nitrogen levels in the water below 50 mg NO3/l in rivers and below 90 kg N/ha in the upper 90cm of the soil.
Strawberry in soil is fertigated with t-tape and growers are obligated to send in soil samples throughout the year to look at the nitrogen content of the soil. If norms are exceeded restrictions in fertilisation are applied for the following year. Within Fertinnowa we try to implement the German KNS-system in Belgium to make growers aware of the nutrients the soil can supply and to only amend with fertilizer to meet the total plant demand. Growers have to learn to take soil samples before planting and at least once during the cultivation to know what the soil can deliver in nitrogen. Also, mineralisation is taken into account in KNS, and growers finally just have to add fertilizer to meet the total crop demand for nitrogen.
At the research centre, the visitors and growers were shown a field where Fertinnowa compared a strawberry cultivation fertilized towards the full crop need with a fertilized cultivation based on the KNS-system. During the field visit, we explained how to use KNS-tables and which simple calculations give the necessary output to know the weekly nitrogen fertigation rates that are needed for the crop.
Growers were informed how to deal with KNS-tables:
- How to take soil samples and how many are needed?
- How to interpret analyses?
- How to estimate the mineralisation capacity of the soil?
- How to construct the total crop need for nitrogen?
- How to calculate the amending amounts of nitrogen in KNS-systems?
You can find the presentation here.