Can wheat yield, N use efficiency and processing quality be improved simultaneously?

Increasing grain yield and quality are the two most important objectives in wheat production. In this study, grain yield, processing quality parameters, protein component concentration, nitrogen uptake and grain nitrogen source were compared under micro-sprinkler irrigation (MSI) and conventional border irrigation (CBI) treatments by field and isotope micro-plot experiments. The results showed that the MSI treatment with late and split application N increased grain yield, protein concentration, post-anthesis nitrogen accumulation amount and fertilizer nitrogen use efficiency by 5.8%, 8.6%, 42.5% and 15.8%, respectively, compared with CBI treatment. The results of isotope micro-plot test showed that the proportion of nitrogen from topdressing nitrogen in mature grains was 30.1% in MSI, which was 80.6% higher than that of CBI. What’s more, the increase in nitrogen uptake in MSI was mainly due to the increase in nitrogen uptake in chaff and grains. MSI treatment increased the concentrations of protein and its components in grains, especially the concentration of storage protein, thus resulting in the increase in wet gluten content, but did not significantly change grain processing quality parameters. In addition, MSI treatment significantly improved fertilizer nitrogen utilization efficiency by applying topdressing in different stages. In general, MSI management may be an efficient way to simultaneously increase grain yield, protein concentration and fertilizer nitrogen use efficiency and stabilize grain processing quality of winter wheat in the North China Plain.