In 2023, 4 bio-based fertilizers from the SEA2LAND project were tested under organic conditions on Broccoli production. The results were compared to a commonly used fertilizer in organic farming (chicken manure) and to no addition of fertilizer. In total, all the plots received the equivalent of 120 kg N/ha (except for the “No Fert” treatment). The results at harvest (fresh weight (grams) of broccoli heads with commercialized standards) indicate a good performance of all tested fertilizers with the best results obtained with the hydrolysate of liquid formulation (Italy). Although spring and summer conditions were extremely difficult in Belgium for the year 2023, these results are encouraging and show the potential of these bio-based fertilizers, in particular for this crop and under organic conditions.

For liquid formulations such as hydrolysate from UNIVPM (Italy) and liquid fertilizer from FERTINAGRO (Spain), it is recommended to apply the product diluted 5 times in water and to avoid a post-planting application of the product (pre-planting application of the product is favorable). For solid formulations such as dried fish sludge from Grønn Gjødsel (Norway) and organic fertilizer from CATAR (France), both pre and post-planting applications are possible.

Fig. 1: Field trial in Upigny (Belgium) where broccoli (var: Parthenon) was grown under organic conditions with 6 different treatments (see Figure 2 for treatment details)


Fig. 2: Fresh weight (grams) of broccoli heads (size > 8 cm)as influenced by Sea2Land Fertilizers under organic conditions in Upigny (Belgium) in 2023 (SP:liquid fertilizer, IT:hydrolysate, NOR:dried fish sludge, FRA:organic fertilizer, Chicken Manure : common organic fertilizer used under Belgian conditions; No Fert: no fertilizer added)

Further information: Full details of this field trial can be obtained by contacting Cécile Thonar (, Nicolas Luburić ( or Eddy Montigny (
A publication will also be elaborated and a link will be given on the SEA2LAND website once it is released.