Acta Agriculturae Zhejiangensis ›› 2022, Vol. 34 ›› Issue (9): 1995-2003.DOI: 10.3969/j.issn.1004-1524.2022.09.18

• Environmental Science • Previous Articles     Next Articles

Effects of non-grain transition of agricultural planting structure on nitrogen and phosphorus loss from cultivated land

QIU Lefeng1(), ZHANG Ling2, XU Baogen1, WU Shaohua1, XU Mingxing3,*()   

  1. 1. Institute of Land and Urban-Rural Development, Zhejiang University of Finance & Economics, Hangzhou 310018, China
    2. Hangzhou Xuelian Land Planning and Design Consulting Co., Ltd., Hangzhou 310030, China
    3. Zhejiang Institute of Geological Survey, Hangzhou 311200, China
  • Received:2021-08-03 Online:2022-09-25 Published:2022-09-30
  • Contact: XU Mingxing

Abstract:

In the present study, Cixi City, Zhejiang Province, was selceted as the case area. The non-grain index (NGP) was eatablised to reveal the non-grain tansition process of agricultural planting structure in Cixi. Based on the field survey, literature research and statistical yearbook data, the amount of nitrogen and phosphorus input and runoff loss in cultivated land in Cixi was estimated, and the effect of non-grain transition of agricultural planting structure on nitrogen and phosphorus loss from cultivated land was evaluated, to provide scientific basis for in-depth understanding of the ecological effects of non-grain transition of agricultural planting structure and reasonable control of agricultural non-point source pollution. It was shown that there was a shift from grain crops to cash crops in agricultural planting structure in Cixi from 1995 to 2019. Judged by the established NGP, this shift processs could be divided into three periods: a stable rise period (1995-2007), a fallback (2007-2013) period, and a rapid rise period (2013-2019). During 1995-2019, the planting area of grain crops fell sharply by 49.3%, while the planting area of vegetables and fruits increased by 113.8% and 108.4% respectively. From 2001 to 2018, the growth rates of total nitrogen and phosphorus input of planting structure in Cixi reached 38.8% and 249.5%, respectively. By 2018, the nitrogen and phosphorus runoff losses of planting structure in Cixi were 2 823.3 t and 971.5 t, respectively. With the non-grain transition of agricultural planting structure, the vegetable field has replaced paddy field as the primary source of nitrogen and phosphorus loss from planting structure, which accounted for 70.9% and 89.2%, respectively, of the total annual nitrogen and phosphorus loss from the planting structure in Cixi, and has become a key target for agricultural non-point source pollution control. It was suggested that different regions should formulate differentiated management and control policies for different types of non-grain production, and the loss of nitrogen and phosphorus should be added to the soil quality evaluation system to provide basis for guiding the next stage of planting structure adjustment.

Key words: land ecology, soil quality, loss coefficient, pollution risk

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