The Middle East and North Africa (MENA) region has the largest water deficit in the world. It also has the least food self-sufficiency. Increasing food imports and decreasing domestic food production can contribute to water savings and hence to increased water security. However, increased domestic food production is a better way to achieve food security, even if irrigation demands an increase in accordance with projected climate changes. Accordingly, the trade-off between food security and the savings of water and land through food trade is considered to be a significant factor for resource management, especially in the MENA region. Therefore, the aim of this study is to analyze the impact of food trade on food security and water-land savings in the MENA region. We concluded that the MENA region saved significant amounts of national water and land based on the import of four major crops, namely, barley, maize, rice, and wheat, within the period from 2000 to 2012, even if the food self-sufficiency is still at a low level. For example, Egypt imported 8.3&thinsp;million&thinsp;t&thinsp;yr<span classCombining double low lineinline-formula>ĝ'1</span> of wheat that led to 7.5&thinsp;billion&thinsp;m<span classCombining double low lineinline-formula>3</span> of irrigation water and 1.3&thinsp;million&thinsp;ha of land savings. In addition, we estimated the virtual water trade (VWT) that refers to the trade of water embedded in food products and analyzed the structure of VWT in the MENA region using degree and eigenvector centralities. The study revealed that the MENA region focused more on increasing the volume of virtual water imported during the period 2006-2012, yet little attention was paid to the expansion of connections with country exporters based on the VWT network analysis. © 2018 The Royal Society of Chemistry.

Oil and gas extraction in the western United States generates significant volumes of produced water (PW) that is typically injected into deep disposal wells. Recently, crop irrigation has emerged as an attractive PW reuse option, but the impact on plant immune response is not known. In this study, we conducted a 3-month greenhouse pot study. Spring wheat (Triticum aestivum) was irrigated 3 times a week with 150 mL (∼80–100% of soil water holding capacity) with one of four irrigation treatments: tap water control, 10% PW dilution, 50% PW dilution, and salt water (NaCl50) control containing the same amount of total dissolved solids as PW50 to determine the effect on disease resistance. The wheat leaves were inoculated with either bacterial or fungal pathogens and changes in pathogenesis-related PR-1 and PR-5 gene expression were measured from the leaf tissue. PW50 experienced the largest relative suppression of PR-1 and PR-5 gene expression compared to noninfected wheat, followed by PW10, NaCl50, and the tap water control. A combination of PW contaminants (boron, total petroleum hydrocarbons, and NaCl) are likely reducing PR-gene expression by reallocating metabolic resources to fight abiotic stresses, which then makes it more challenging for the plants to produce PR genes to fight pathogens. This study provides the first evidence that plant disease resistance is reduced due to irrigation with reused PW, which could have negative implications for food security.

Extreme climate change, rapid population growth and economic development drive a growing demand for resources, which lead to energy, food, water and their intertwined nexus becoming increasingly important. Agricultural decisions considering the interconnections among water, energy, and food are critical. The consumption of large amounts groundwater and non-renewable energy by the predominant traditional wheat-maize cropping system has caused a serious water shortage in the North China Plain (NCP), which is a large food production region in China. This situation has strained the relationship between water/energy consumption and food production. It is important to seek synergy in the water-energy-food nexus. This paper proposed a relative index of water-energy-food (WEFRI) based on different values of resource consumption and use efficiency between treatment systems and control system to analyze the synergy between water utilization, energy consumption and food supply in different cropping systems at the field scale. The goal is to seek a sustainable cropping system to balance crop production while reducing energy consumption and water depletion. In this case, different systems including monocropped maize (Zea mays) (MM), intercropped maize and soybean (Glycine max) (MS), relay cropped of maize with pea (Pisum sativum) (MP) and potato (Solanum tuberosum) (MO), rotation of maize with spinach (Spinacia oleracea) (MI) and ryegrass (Secale cereale) (MR), and using traditional wheat-maize (Triticum aestivum) (MW) as a control. MM, MS, MP and MO were the best systems within a particular range of food supply reduction. The WEFRI of the MM/MS system was the highest (2.96/2.78). Compared to the MW system, the groundwater consumption of MM/MS was reduced by 73.84%/73.84%, and non-renewable energy inputs were reduced by 48.01%/48.30%; however, the food supply decreased by 48.05%/51.70%. The WEFRI of the MP system was 1.98. In comparison with the MW system, the groundwater consumption of the MP system was reduced by 28.46%, and the non-renewable energy inputs were reduced by 42.68%. However, the food supply decreased by 37.13%. The WEFRI of MO system was 1.92. Compared to the MW system, the groundwater consumption of MO was reduced by 11.47%, non-renewable energy inputs were reduced by 32.14%, and the food supply only decreased by 26.27%. In conclusion, we theoretically proposed the following references for cropping systems in the NCP: MM and MS are implemented when the areas has extreme water shortages, MO is implemented when a less than 30% reduction in the food supply capacity is acceptable, and MP is recommended if a 30%–40% reduction in the food supply is acceptable.

The relationship between structural and foaming properties of two tryptic and two peptic wheat gluten hydrolysates was studied at different pH conditions. The impact of pH on foam stability (FS) of the samples heavily depended on the peptidase used and the degree of hydrolysis reached. Surface dilatational moduli were in most, but not all, instances related to FS, implying that, although the formation of a viscoelastic protein hydrolysate film is certainly important, this is not the only phenomenon that determines FS. In contrast to what might be expected, surface charge was not a major factor contributing to FS, except when close to the point-of-zero-charge. Surface hydrophobicity and intrinsic fluorescence measurements suggested that changes in protein conformation take place when the pH is varied, which can in turn influence foaming. Finally, hydrolyzed gluten proteins formed relatively large particles, suggesting that protein hydrolysate aggregation probably influences its foaming properties.

The increasing dependency on groundwater, especially in irrigated regions, has highlighted the notable place of groundwater resources within the water-food-energy nexus (WFEN). This role is particularly relevant in the Haihe River basin of China, a globally representative area that is experiencing rapid aquifer depletion. The winter wheat (Triticum aestivum L.) fallow strategy may have the potential to limit withdrawal in this region. Based on information from multiple sources, this paper proposed six kinds of fallow schemes—under the same triple-cropping system consisting of winter wheat and summer maize (Zea mays L.) followed by fallow and summer maize in two years (WW–SM/F–SM) but with different irrigation schemes—as scenarios to conduct detailed simulation by a modified Soil and Water Assessment Tool (SWAT) model. Then, the water balance components of the shallow aquifer and soil profile (2 m) under different scenarios were analyzed to quantify the variations in hydrological processes caused by changes in cropping system and pumping intensity. Furthermore, through 17 indices that could quantitatively describe the changes related to the WFEN, the effects of seasonal fallow schemes on shallow groundwater drawdown mitigation, grain yield reduction, and energy consumption savings were evaluated. Based on these evaluation outcomes, linear programming was used to optimize the fallow schemes at the subbasin scale. As a result, to satisfy the constraint of stopping groundwater drawdown as well as improving water and energy productivities, the minimum reduction in the annual average winter wheat yield would be 55% compared with the basic scenario, while the summer maize yield would remain basically stable. Under the optimized fallow scheme pattern, 66% of the well-irrigated cropland should adopt the WW–SM/F–SM system with two irrigation applications for winter wheat and a rain-fed scheme for summer maize; additionally, 24% of the well-irrigated cropland should adopt the WW–SM/F–SM system with one irrigation application for winter wheat and a rain-fed scheme for summer maize, and the recommended fallow schemes for the other 10% of well-irrigated cropland varied spatially. Compared to the basic scenario, the optimized fallow scheme pattern could decrease shallow groundwater exploitation by 36.5 × 10⁸ m³ a⁻¹ (i.e., to realize shallow groundwater equilibrium), reduce the diesel consumption of agricultural machines and electricity consumption of pumping wells by 32% and 90%, respectively, and save energy costs by approximately 873 yuan ha⁻¹. These results could provide a quantitative reference for policy-making in this watershed and serve as a typical case for similar areas that wish to implement fallow strategies to achieve groundwater sustainability.