The uptake of nitrogen increases op to 6-11 % by placing the slurry in the ridge compared to normal spreading of slurry. A frequent problem in organic potatoes is low content of dry matter in the tubers, due to early wilting and immaturity caused by potato late blight. Pre sprouting promote early growth, but fertilizers should also be available early in the growth period. Precise supply of fertilizers in organic potato growing can increase plant vigour, yield and quality. The document shows the constraints and benefits by using broad spread and placed slurry. The nitrogen uptake increased op to 6-11 %, when the slurry was placed compared to normal spreading. There was a tendency that the fraction of large tubers was higher when the slurry was placed.
