Organic Fertilization of Red Raspberry cv. ‘Glen Ample’, in Polyethylene Tunnels in Norway By Rolf Nestby: Norwegian Institute for Agricultural and Environmental Research, Grasland and Landscape Division, Kvithamar, 7500 Stjørdal, Norway. Ingrid Myrstad: The Norwegian Agricultural Extension Service (LFR), 9410 Borkenes, Norway.

Challenges and frames of the project Experiments in fields at 62, 65 and 68 °N These fields have very different soils. Challenge to cover nutrient needs with organic fertilizers, especially considering fertigation. Project period 2007 to Financed by the Norwegian Research Council Fertilization is one of four objectives of the project.

The field at 62 °N, Innvik, Norway Mineral soil - pH 5.7 P-K-Mg-Ca: (Al-methode)

The field at 65 °N, Brønnøysund, Norway Mineral soil – pH 7.7 (sandy loam) P-K-Mg-Ca:

The field at 68°N, Harstad, Norway. Mineral soil with 40% organic matter P-k-Mg-Ca:

Potassium deficiency at 68 °N Summer 2007

Management Fertilizers Agromarin – Based on organic material from Marin and Agriculture sources. ( ) Marihøne Pluss – Based on bone powder and vinasse (8-3-3). OASE for fertigation (8-4-6) Levels of N 9, 13,17 Other macro nutrients are balanced to level of N. Solid fertilizer are given in spring and mid summer. Fertigation from mid summer to end of harvest.

Conclusion Registrations in 2007 showed small effects in growth and yield. Deficiency symptoms observed in two fields (K, Mn, Fe). Only one field was fully grown in The experiments will be better balanced. Testing of fertilizers for fertigation will be undertaken