Impact of the changing area sown to winter wheat on crop water footprint in the North China Plain

Abstract

a b s t r a c tThe serious water scarcity and groundwater over-exploitation problems of the North China Plain (NCP) have aroused worldwide concerns. Achieving a reduction in agricultural water use is critical, because agriculture is the largest water consumer in the NCP. New solutions to these problems may lie in changes in the area sown to winter wheat across the NCP. In this study, the water footprint (WF) was applied as an aggregative indicator to evaluate the impact of the changing area sown to winter wheat. A Chinese version of the AEZ model, the China-AEZ model, was used for the evaluation. The results showed: (1) Green water plays a more significant role in winter wheat production in the southern part of the NCP than in the north; about a half of the water requirements for winter wheat are met by green water in the southern part of the NCP, compared to only a third in the north. (2) As a result of the north-south shift in the area sown to winter wheat during the period 1998-2011, the WF, the green water footprint (WF green ) and the surface water footprint (WF s blue ) for winter wheat increased, respectively, by 459 × 10 6 m 3 yr −1

Irrigation Water Availability and Winter Wheat Abandonment in the North China Plain (NCP): Findings from a Case Study in Cangxian County of Hebei Province

“…As alternatives, surface water from rivers and reservoirs has been proposed, and the expansion of areas irrigated by surface water should be a tradeoff between groundwater conservation and food security on the NCP [8]. However, the surface water supply is erratic, and the IWA of surface waters from rivers and reservoirs is much lower than that of groundwater.…”

“…Changes in cropping systems are mainly marked by the abandonment of winter wheat, a phenomenon that also characterizes the NCP; spatially continuous areas that were previously utilized for winter wheat/summer maize double-cropping are gradually being replaced by the single-cropping of spring corn [11]. Although this land use change has undoubtedly influenced food production on the NCP [8], little is currently known about its causes [12].…”

“…Since the late 1990s, however, there have been tremendous agricultural land use changes on the NCP, mostly in terms of cultivated land conversion in peri-urban areas and changes of cropping systems within the purely agricultural hinterland [8,9]. A number of research studies have addressed the characteristics of cultivated land conversion on the NCP, noting the fact that the expansion of urban areas and related land occupation has been a crucial factor in arable land loss [9,10].…”

“…The high and stable yields of winter wheat can only be achieved by irrigation, and more than 70% of irrigation water (i.e., the vast majority of total water use on the NCP) is consumed by winter wheat; the growth of this crop leads to the development of water scarcity and the overexploitation of groundwater [15,16]. Previous studies in this area have mainly focused on the effects of winter wheat production on the NCP water scarcity, analyzing water consumption and usage due to winter wheat and related crop rotations in order to find solutions for this key issue [8,[17][18][19]. Taking a different perspective, irrigation water is crucial for the growth of winter wheat [12,20]; thus, irrigation water availability (IWA), related to water scarcity, is a probable factor affecting the abandonment of this crop.…”

Ecological compensation for winter wheat abandonment in groundwater over-exploited areas in the North China Plain

“…Hu et al (2010) proposed that the percentage reduction in amount of local groundwater withdrawal should be no less than 29.2% in order to stop groundwater drawdown, and it should be more than 39.2% in order to induce groundwater recovery and restoration to the pre-development hydrologic conditions of the mid-1950s. Considering only the groundwater consumption of winter wheat, the above two thresholds of 29.2% and 39.2% were also used to determine the percentages of winter wheat abandonment, since the percentage shrinkage in sown areas of winter wheat approximately equaled the percentage reduction in groundwater consumption in the NCP (Wang et al, 2015). The corresponding net profits were 273 yuan/mu and 341 yuan/mu, respectively (Figure 4).…”