Effects of nitrogen application patterns on the dry matter accumulation and nitrogen uptake in salt-tolerant winter wheat

【Objectives】Salt tolerant winter wheat as salinization area pioneer crop, combined with proper rotation, can not only increase the productivity of saline soil, but also improve the plough layer features of saline alkali soil. In the fertilizer management, however, salt tolerant winter wheat does not form a unified management pattern, its nutrition status is unclear. In order to explore the scientific and reasonable salt tolerant winter wheat nitrogen fertilization technology pattern, the effect of different nitrogen fertilization patterns on the accumulation of dry matter and nitrogen absorption and utilization was studied.【Methods】Based on winter wheat regional fertilization condition investigation and nitrogen uptake of winter wheat in different growing phases, four fertilization patterns were tested using field plot trail. Samples were collected in different periods of winter wheat plant for the determination of nitrogen absorption and dry matter weight and the output. The winter wheat nitrogen uptake and the dry matter accumulation were calculated using related formula.【Results】1) The largest differences in the dry matter accumulation and nitrogen accumulation in all treatments were observed from the greening to the booting stages. The accumulation amounts of dry matter and nitrogen accumulation in N300/2 (farmers used fertilization) and N210/3 (210 kg/ha, three times application, basal 1/3, jointing fertilization 1/3 and earing fertilization 1/3) treatments are significantly higher than those of N150/3 and N0(no N applied) treatments. 2)In greening, booting and the harvest stages, the nitrogen content of CK is the lowest, significantly lower than those of nitrogen treatments, but the differences are not significant among all the nitrogen treatments. 3) There are not significant differences in dry matter and nitrogen accumulation of wheat between treatment of N210/3 and the farmers'practice. 4) The nitrogen utilization efficiency of N210/3 reaches 40.7%, significantly higher than that of N300/2. 【Conclusions】The accumulation of dry matter of salt tolerant winter wheat during seedling and greening period is slow, increases quickly from the greening to booting stage, slowly from the booting to the mature stage, showing a tendency of slow-fast-slow. The largest amount of nitrogen is accumulated from the greening to the booting stage, demanding the most urgent nitrogen supply from fertilizer. For the same yield of salt tolerant winter wheat, applying nitrogen fertilizer in different development stages enhances the efficiency of nitrogen utilization.