Effects of ecological environment and nitrogen application rate on microelement contents of wheat grain

【Objectives】 Microelements are important parts of wheat grain. The contents of Fe, Mn, Cu and Zn, not only directly affect the growth of wheat plants, but also the nutritional quality of wheat grain. The micronutrient contents are varied in different ecological regions, cultivars as well as fertilization practices. To provide a reference for stable development of wheat quality, effects of different ecological environment and cultivation on microelements contents in wheat grain were studied through a synchronous test.【Methods】Experiment were carried out simultaneously in three ecological test sites, namely Renqiu, Beijing and Zhaoxian in 2009-2011. Split plot design was used with the test area as the main plot, nitrogen level as subplot, which is arranged with 0, 90, 180, 270 and 360 kg/ha and wheat cultivar as sub-subplot, which includes Jimai 20, Wanmai 38, Jingdong 8 and ZhongMai 8. The contents of microelements (Fe, Mn, Cu, Zn) in wheat grain from different plots were determined after the harvest. The microelement contents in different ecological conditions and nitrogen levels were analyzed, and the ecological stability of the microelement contents and regulate compensation effect of nitrogen application on the microelement contents under different environment conditions were discussed.【Results】1) The results show that the contents of microelements (Fe, Mn, Cu and Zn) are affected by all the three factors significantly. The highest difference is from ecological environment. The absorption of precipitation Fe and Mn is affected, and Zn element by soil organic matter content and latitude of experiment site. Soil potassium content can promote the Fe, Mn, Cu and Zn absorption and utilization in wheat. 2)Within the 0-360 kg/ha of N fertilizer use levels, the N fertilizer application is beneficial for the absorption of Fe, Cu and Zn by wheat, not to that of Mn. Proper application of N fertilizer is beneficial to reducing variations in the contents of Fe, Mn and Zn caused by ecological enviroment, not obvious to that of Zn among environments. The moderating effects of N fertilizer on the grain microelement contents are different in wheat cultivars. Proper application rate of nitrogen fertilizer narrows the differences of the contents of Fe, Mn and Zn in cultivars. 【Conclusions】The effect of cultivation environment on the micronutrient contents of wheat grain is higher than that of genetic factors, that is, the microelement contents have strong cultivation plasticity. Nitrogen fertilizer has compensation effect to the instability of the microelement contents caused by adverse ecological environments or cultivars. Reasonable cultivation environment can effectively improve the micronutrient contents in wheat grains.