Effect of additions of nitrogen and sulfur to irrigated wheat at heading on grain yield, composition and milling and baking quality

摘要

The effects of adding nitrogen (N) and sulfur (S) to wheat (Triticum aestivum L. cv. Matong) at heading on the concentrations of nutrients in the plant, on grain and flour composition and milling and baking quality were studied. The crop was grown on a red- brown earth in the Goulburn Valley irrigation area of northern Victoria. There were 2 application rates of urea, 0 and 50 kg N/ha combined factorially with 2 application rates of calcium sulfate, 0 and 20 kg S/ha.Additions of N increased the concentrations of both N and S in the grain and increased protein level, but grain N:S ratio remained unaffected. Sulfur application had no effect on grain composition or on flour or dough properties. A standard range of baking tests showed that the extra protein synthesised was functional protein contributing to the dough properties in an additive manner. The N treatment lowered the hot paste viscosity and the brightness of the cold paste suggesting that there was a qualitative effect on the starch component as well as a lowering of starch content as the protein increased. There was no indication of any deleterious effects on quality arising from the late application of N as has been found by other workers.