Changes in nitrogen budget and potential risk to the environment over 20years (1990–2010) in the agroecosystems of the Haihe Basin, China

Abstract

The nitrogen balance can serve as an indicator of the risk to the environment of nitrogen loss from agricultural land. To investigate the temporal and spatial changes in agricultural nitrogen application and its potential threat to the environment of the Haihe Basin in China, we used a database of county-level agricultural statistics to calculate agricultural nitrogen input, output, surplus intensity, and use efficiency. Chemical fertilizer nitrogen input increased by 51.7% from partly due to fertilizer composition and type improvement. This level indicates that more than half of nitrogen inputs are lost in agroecosystems. Our results suggest that although the improvement in fertilizer composition and types has partially offset the decrease in nitrogen use efficiency, the environmental risk has still increased gradually over the past 20 years, along with the increase in crop yields and nitrogen application. It is important to achieve a better nitrogen balance through more effective management to significantly reduce the environmental risk, decrease nitrogen surplus intensity, and increase nitrogen use efficiency without sacrificing crop yields.

Relationships between river water quality and landscape factors in Haihe River Basin, China: Implications for environmental management

“…Water resources in the Haihe River Basin are among the most polluted in China (Zheng et al, 2015). Among the 15 third grade Water Resource Zones, water quality was generally better in the mountainous zones than in the plain zones, which is consistent with the research results obtained by Sun et al (2013).…”

“…Furthermore, the agricultural chemical fertilizer application is still increasing. Chemical fertilizer nitrogen input increased by 51.7% between 1990 and 2010 and by 37.2% from 2000 to 2010, concomitant with increasing crop yields (Zheng et al, 2015).…”

“…Intensive agricultural activities (Zheng et al, 2015), rapidly developing industry and urbanization, and dense population all greatly change the terrestrial ecosystem patterns in the river basin, increase the output of industrial point source pollution and agricultural non-point source pollution, and significantly impact river water quality. According to the Haihe River Water Conservancy Commission′s Water Resources Bulletin (2010) (http://www.hwcc.gov.cn/pub/hwcc/static/szygb/gongba o2010/index.htm), ′seriously polluted′ water, ′modera-tely polluted′ water, and ′clean′ water accounted for 48.2%, 14.6%, and 37.2%, respectively, in an evaluated stretch of river in the Haihe River Basin.…”

Controlling River Eutrophication under Conflicts of Interests—A GIS Modeling Approach

“…Over-fertilization was estimated only in 40,529 ha, equivalent to 4.5% of total agricultural area. This strongly contrasted many other regions of the World where the agro-economic boom is characterized by increasing yields and steady nutrient surpluses [18].…”

The Synergic Characteristics of Surface Water Pollution and Sediment Pollution with Heavy Metals in the Haihe River Basin, Northern China

“…The Haihe River Basin, one of the most important river basins in China, is within China's central political, economic, and cultural area, where approximately 140 million people live [15]. With the rapid development of agriculture and industry in the Haihe River Basin, pollution has become serious [16][17][18].…”