Virtual water or land use is the volume of water or area of land, respectively, used to produce a unit food commodity that is traded. Estimates of future virtual water or land use (as potential mechanisms for mitigating against food insecurity due to resource scarcity) are limited by the need for complex modelling and data requirements regarding trade, for which the data or expertise might be rare or unavailable. This paper presents a simple food balance approach for estimating the status quo food demand and supply and associated virtual water or land use transfers under future conditions. The method is spatially-scalable, accessible to a wider range of users, and illustrated using UK feed barley supply. Key features of the method are: ● Proportionate distribution of a target food item over utilization components is estimated from the FAO Food Balance Sheet of the country of analysis and used to distribute future supply over utilization components. ● The balance between demand and supply is used to estimate the direction and magnitude of virtual water or land use transfers. ● The method can be scaled up from national to regional and global levels and to cover multiple food items.

Synergic management of the local crop-biomass coproduction system is the potential to increase resource efficiency and promote sustainable development. In this paper, an interval fuzzy linear fractional programming (IFLFP) model is developed for planning regional food production with the consideration of ecological protection, water resource conservation, biomass energy supply, and food-energy-water (FEW) nexus. The main advantages of the proposed IFLFP model are the abilities to reflect uncertainties with different characters as interval values and fuzzy sets and to provide system efficiency measurement by the ratio form of conflict objective functions. The IFLFP model is then tailored for the application of the crop-biomass coproduction management with FEW nexus in Jiangsu Province, China. The influences of different optimization goals (i.e. economic benefits and environmental benefits per unit irrigation water consumption) and multiple water resource scenarios under climate change are examined and discussed to provide more managerial insights. The results reveal that wheat, barley, and tuber crops would be more easily affected by water resource availability and optimization goals. Besides, recycle water would be considered as an important source for irrigation under scare water scenario, and gain the priority for the economic purpose. The results also imply that it is impossible to realize “double-win” of environmental and economic goals simultaneously, and decision makers should make compromises among different strategies.

Water-Energy-Food (WEF) Nexus and CO₂ emissions for a farm in northwest Iran were analyzed to provide data support for decision-makers formulating national strategies in response to climate change. In the analysis, input–output energy in the production of seven crop species (alfalfa, barley, silage corn, potato, rapeseed, sugar beet, and wheat) was determined using six indicators, water, and energy consumption, mass productivity, and economic productivity. WEF Nexus index (WEFNI), calculated based on these indicators, showed the highest (best) value for silage corn and the lowest for potato. Nitrogen fertilizer and diesel fuel with an average of 36.8% and 30.6% of total input energy were the greatest contributors to energy demand. Because of the direct relationship between energy consumption and CO₂ emissions, potato cropping, with the highest energy consumption, had the highest CO₂ emissions with a value of 5166 kg CO₂eq ha⁻¹. A comparison of energy inputs and CO₂ emissions revealed a direct relationship between input energy and global warming potential. A 1 MJ increase in input energy increased CO₂ emissions by 0.047, 0.049, 0.047, 0.054, 0.046, 0.046, and 0.047 kg ha⁻¹ for alfalfa, barley, silage corn, potato, rapeseed, sugar beet, and wheat, respectively. Optimization assessments to identify the optimal cultivation pattern, with emphasis on maximized WEFNI and minimized CO₂ emissions, showed that barley, rapeseed, silage corn, and wheat performed best under the conditions studied.

Availability of sufficient and clean freshwater has become a growing constraint to sustainable agricultural development in many countries. We explore two pathways that hold the potential to reduce water consumption and pollution related to cereal production in Iran: reducing food waste and changing cropping patterns. Hereto, we first evaluated the green, blue and grey water footprint (WF) associated with production of wheat, barley and rice. Next, we assessed resulting water scarcity and pollution levels at the provincial scale, for the period 1980–2010. Both total WF and its blue water share were found to have increased considerably from 1980 on. For the year 2010 (a representative hydrological year), results show that the national total green–blue WF of production of these major cereals is 43 × 10⁹m³. Regarding the grey WF of production, 30 × 10⁹m³ was required to take up surplus N loads to water bodies. Resulting blue water scarcity and water pollution levels are highest in the arid and semi-arid provinces, caused in part by cereal production destined for export to other regions. Exploring reduction pathways showed that bridling cereal waste allows a potential reduction in both the green–blue WF and grey WF of production of up to 5% each. Relocating production areas and modifying cereal trade patterns from water-abundant to scarcer provinces could save up to 3.5% in the green–blue WF of production and up to 25% in the grey WF.

In this study, ultralayered Co₃O₄ adsorbent was synthesized and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The surface area of the solid material was found to be 75.5m²g⁻¹ by BET method. The ultralayered Co₃O₄ was used for the first time as an effective adsorbent for the preconcentration of the Pb(II) ions in various samples prior to flame atomic absorption detection. Analytical parameters affecting the solid phase extraction of Pb(II) such as pH, adsorption and elution contact time, eluent volume and concentration, sample volume and common matrix ions were investigated. The recovery values for Pb(II) were found to be ≥92% even in the presence of 75,000mgL⁻¹ Na(I), 75,000mgL⁻¹ K(I), and 75,000mgL⁻¹ Ca(II) ions. 10s vortexing time was enough for both adsorption and elution contact times. The elution was easily made with 2mL of 2.0molL⁻¹ HNO₃. The reusability (170 cycles) and adsorption capacity (35.5mgg⁻¹) of ultralayered Co₃O₄ were excellent. The preconcentration factor of the method and detection limit were found to be 175 and 0.72µgL⁻¹, respectively. The described method was validated with certified reference material (RM 8704 Buffalo River Sediment, BCR-482 Licken and SPS-WW1 Batch 111-Wastewater) and spiked real samples. It was also applied for the preconcentration of Pb(II) ions in various water (well water, mineral water, waste water and sea water), food (cauliflower and barley), street sediment and tobacco samples.