Soil Management Effects On Nitrogen Use, Grain Yield, Grain Quality and Nutritional Components of Hard Red Spring Wheat.

The influence of soil management on nitrogen (N) use efficiency and food quality was evaluated with hard red spring wheat using plots from a long-term potato-grain cropping systems trial in Maine.  Twenty years of contrasting amended (manure and compost) and nonamended (fertilizer only) soil management treatments resulted in replicated plots with highly divergent soil quality characteristics.  The amended plots had 75% higher soil organic matter, higher CEC, and lower bulk density compared with the nonamended plots.  Three varieties of bread wheat were grown on these plots in 2010 and 2011 and received either pre-plant beef manure (amended plots) or synthetic fertilizer (nonamended plots).  The nonamended plots were split into 4 different fertilizer rates.  The treatments were evaluated for plant N uptake, N use efficiency measures, grain yield, grain protein, flour performance parameters, and flour nutritional components (starch, fructans, antioxidant capacities, and phenolics).  Across the three varieties, yields were equal to or higher in the amended plots than in the nonamended plots.  Grain protein increased with increasing fertilizer rates, but there was no consistent trend for the comparison between amended and nonamended plots. Nitrogen utilization efficiency (grain yield:plant N) and nitrogen harvest index (grain N;plantN) were significantly higher in the amended plots than the nonamended plots for 2 of the 3 varieties in 2010 and across all varieties in 2011.  The more efficient use of nitrogen in the amended plots possibly was due to the more gradual release of N from manure than from fertilizer.  Flour performance and nutritional components also will be presented.