The demand for organic food products has increased dramatically over the past years. In both Denmark and USA the organic sector is growing, but production is lower than demand. In spite of more than twenty years of research on organic crop production, crop yields are in practice still way below potential. There are 4 significant reasons for this: 1) the availability of nutrients already present does not match plant needs due to lack of focus on importance of individual nutrients 2) the availability of nutrients already present does not match plant needs due to poor synchronization in time 3) lack of sufficient nutrien sources 4) existing knowledge is not sufficiently implemented in practice Nutrient balances and soil fertility issues both need more attention in organic systems. Balancing N and P inputs is challenging when manure inputs are a main source of P. Organic farmers are encouraged to augment their production of N via legumes in various portions of the crop rotation, thus allowing lower animal manure application rates to reduce chances of loading soils with too much P. A different approach, however, might be more appropriate where P is more limiting. There are also basic issues of whether the standard soil tests developed for fertilizer-based nutrient applications are adequate for evaluating soil nutrient availability in organic systems that have larger organic matter pools. Denmark and USA share the need to improve resource efficiency in organic crop production and will join forces to focus on optimizing nutrient supply and efficient implementation practices.