Effects of nitrogen rates and soil fertility levels on root nitrogen absorption and assimilation and grain protein content of winter wheat

Soil column culture was used to investigate the effect of nitrogen rate on root nitrogen absorption, assimilation, grain yield, and protein content in different fertility soils The results showed that the upper roots senesced earlier than that deeper roots, which played an important role in nitrogen absorption during later development stage Increased nitrogen rate and high soil fertility promoted root growth and root activity, increased the activity of key enzymes in nitrogen assimilation As a result, high nitrogen rate and soil fertility delayed root senescence and increased grain yield and protein contentKey words: winter wheat; root; nitrogen assimilation; grain yield; protein content