Effects of Crop Nutrition on Wheat Grain Composition and End Use Quality

Increasing applications of nitrogen fertilizer to wheat (from 0 to 288 kg/ha) resulted in an increased proportion of gliadin proteins and increased dough extensibility. Flour from a plot receiving 192 kg/ha N (and no S) was similar to that from a plot receiving 192 kg/ha N and 53 kg/ha S, but the proportion of omega-gliadins was increased and dough strength was more similar to that from plots with lower N. The grain %N from a plot receiving 35 t/ha farmyard manure was similar to that from the plot receiving 144 kg/ha N, indicating that much of the applied N was unavailable. The protein composition and dough properties of flour from this plot were similar to those of grain from conventionally fertilized plots with similar grain N contents. Similar differences in grain N content, protein composition, and functional properties were observed in grain samples from commercial organic and conventional farms.