Nitrogen is an essential nutrient. One of the main challenges of organic farming is to
maintain a positive nitrogen balance. Every time a crop is harvested, nitrogen is
removed from the soil. Without use of synthetic chemical fertilizers, it might be
difficult to maintain an adequate level of available nitrogen in the soil. One solution
is to increase the use and effectiveness of nitrogen fixing plants. Mixed grass and
clover crops are widely used as the basis for the production of organic milk and
meat. The nitrogen-chain in these production systems begins with the fixation of
atmospheric nitrogen by soil bacteria in white clover root nodules. From here it is
transported to the clover plant and then on to neighboring soil and grass before
finally ending up in grazing cows. Because of productivity gains attained using large amounts of synthetic fertilizer, investments in the optimization of the natural nitrogen chain have stagnated. NCHAIN project's goal is to ensure increased supply of biologically fixed N in organic agriculture by optimizing the interactions within the nitrogen chain. We will achieve this by systematically examining the relationship between the yield of clover-grass crops and the genetic composition of the three interacting organisms. To this end, we will develop new statistical methods that specifically take into account the genetic interactions between species