Cover crop variet and seeding date trial

Thirty one cover crops were established on two seeding dates (27 July and 23 Aug.) in Fargo, ND in 2017. Warm-season annuals had greater biomass N accumulation in the first seeding date than in the second seeding date (Figure 11). Cool-season cover crops were not as sensitive to seeding date as warm-season cover crops. Mustard family crops were among the crops that accumulated the most N in their biomass in the first seeding date. Nitrogen scavenging by cover crops protects NO₃-N from leaching, by sequestration in the cover crop biomass until next spring after the cover crop is winter killed or terminated. Availability of the N in the cover crop biomass for the next crop will depend on species, C/N, temperature and water.