Water level control is a key technique to realize the united regulation of irrigation-drainage in a wheat field and plays an important role in improving the ecological environment of the field. In this paper, based on the water level control technology, the change of nitrogen in deep groundwater in winter wheat farmland is studied by using field experiment and laboratory analysis at different growth stages and water depths. It is shown that NH+4-N concentration in groundwater in flooding treatment is less than that in non-flooding treatment at the same drainage intensity, suggesting flooding helps reduce NH+4-N concentration in groundwater. Unfortunately, with the prolonging flooding time, the decreasing rate of NH+4-N concentration gets slow. Under the condition without flooding, the longer the groundwater control time is, the slower the drainage rate is, causing groundwater has enough time to contact with the soil and crop roots, and this is in favor of the decreasing NH+4-N concentration. Additionally, flooding can reduce NO-3-N concentration as well. In the case without flooding, the NO-3-N concentration increases slightly at reviving-tillering and jointing-booting stages under water level control, but the NO-3-N concentration rises considerably at heading-flowering and milking stages. There is a danger of NO-3-N leaching in the whole growth period of winter wheat.
XIAO Meng-Hua-,JIN Qiu-,CHU Lin-Lin-. Effects of waterlogging stress on change in nitrogen of winter wheat in South of China[J]. Journal of Drainage and Irrigation Machinery Engin, 2015, 33(7): 618-625.
Yu Hongmei,Li Zizhong,Gong Yuanshi.Comparison of nitrogen loss and use efficiency of vegetable in vegetable field under traditional and improved water and N-fertilizer management[J].Transactions of the CSAE, 2007,23(2):51-59.(in Chinese)
Yin Guoxi,Zhang Zhanyu,Guo Xiangping,et al.Experimental study on effect of controlled drainage from ground surface on concentration and discharge of nitrogen[J].Journal o f Hohai University: Natural Sciences, 2006,34(1):21-24.(in Chinese)
Guo Hongpeng,Zhu Jingya,Yang Yinsheng.Research status and development of technologies for controlling the agricultural non-point source pollution[J].Transactions of the CSAE, 2008,24(4):290-295.(in Chinese)
Chirinda N, Carter M S, Albert K R, et al. Emissions of nitrous oxide from arable organic and conventional cropping systems on two soil types[J]. Agriculture, Ecosystems & Environment, 2010,136(3/4):199-208.
Li Hua,Liang Xinqiang,Chen Yingxu,et al.Ammonia volatilization from urea in rice fields with zero-drainage water management[J].Agricultural Water Management, 2008,95(8):887-894.
Zhu Zhaoliang.Loss of fertilizer N from plants-soil system and the strategies and techniques for its reduction[J].Soil and Environmental Science, 2000,9(1):1-6.(in Chinese)
Luederitz V, Eckert E, Lange-Weber M, et al. Nutrient removal efficiency and resource economics of vertical flow and horizontal flow constructed wetlands[J]. Ecological Engineering, 2001,18(2):157-171.
Du Wenyong,He Xiongkui,Hu Zhenfang,et al. Effect of different irrigation technology on production of winter wheat[J].Journal of Drainage and Irrigation Machinery Engineering, 2011,29(2):170-174.(in Chinese)
Shao Guangcheng,Yu Shuang′en,Liu Na,et al.Application of path analysis in sensitivity analysis on stress indicator from subsurface water logging of winter wheat[J]. Journal of Basic Science and Engineering, 2011,19(4):527-534.(in Chinese)