Fig. 2. Grain yield of wheat during the 4 yr. F test was significant at p = 0.02, p < 0.01, and p = 0.04, for the years 1997, 1999, and 2000, respectively, and not significant for 1998. Manure, injection of 40 Mg ha^-1 yr^-1 (wet weight basis) liquid dairy cattle manure before seeding; N-single + P, application of 120 and 26 kg ha^-1 yr^-1 N and P, respectively, as single basal dressing before seeding; N-split + P, application of 60 and 26 kg ha^-1 yr^-1 N and P, respectively, as basal dressing before seeding and 60 kg N ha^-1 yr^-1 at tillering.