Modern agriculture calls for efficient and environmental-friendly agricultural water and land management practice. Agricultural water and land utilization mode has a great impact on the amount of carbon emissions, and thus the aim of this work is to propose an optimal modeling approach for generating efficient agricultural water and land management alternatives and reducing carbon emission in agricultural water-energy-food nexus system. This study presents a novel approach consisting of carbon footprint lifecycle assessment method and bi-level multi-objective stochastic programming model. The proposed approach has contributions in following aspects: (1) the environmental impact of different resource allocation strategies can be measured in optimization (2) the spatial variability of spatial data (e.g., ET₀ and precipitation); can be fully reflected via remote sensing information; (3) tradeoffs among two decision-making levels and their conflicting objectives under randomness of surface water availability can be addressed. The proposed approach was applied to the middle reaches of the Heihe River basin, northwest China. After solving the proposed model, the optimal water and land use alternatives under different hydrological years can be generated. Decision makers can plan agricultural production strategy according to optimization schemes, and reduce carbon emission through increasing vegetable cultivation and surface water utilization. Furthermore, the performance comparison of different models indicated that fierce conflicts exist between income fairness and economic benefits. The comprehensive evaluation value of bi-level multi-objective stochastic programming model is 0.7036, which is highest among single- and multi-objective models, showing that such model has obvious advantage in dealing with multiple decision-making levels and conflicting objectives. This approach can help decision makers of similar regions manage the agricultural production system in a more efficient and environment-friendly way.

In this study, an inexact fractional programming method is employed for planning the regional-scale water-energy-food nexus (WEFN) system. The IFP cannot only deal with uncertainties expressed as interval parameters, but also handle conflicts among multiple decision stakeholders. The IFP approach is then applied to planning the WEFN system of Henan Province, China. An IFP-WEFN model has been established under consideration of various restrictions related to water and energy availability, as well as food demand. Solutions of the planting areas for different crops in different periods have been generated. The results suggested that there would be a significant increase for vegetable cultivation with an increasing rate of 24.4% and 30% respectively for the conservative and advantageous conditions, followed by the fruit cultivation. In comparison, the planting area of cotton would be decreased with a decreasing rate of 21.2%, and there would also be an explicit decrease for rice cultivation. These results can help generate a desired planting scheme in order to achieve a maximized unit benefit with respect to the water utilization. Comparison between the IFP-WEFN model and the ILP-WEFN model indicates that, even though a slightly lower benefit is obtained from IFP-WENF model, it can result in a higher unit benefit than the planting scheme from ILP-WEFN model. Consequently, the IFP-WEFN model can help decision-makers identify the sustainable agricultural water resources management schemes with a priority of water utilization efficiency.

Low agricultural productivity is a major challenge constraining food production in developing countries. Attempts at addressing the problem have resulted in the development and deployment of agricultural technologies, such as organic farming, to help boost productivity, enhance farmers’ income, and their overall livelihood conditions. The deployment of such productivity-enhancing technologies has mostly overlooked their inexplicable interconnectedness and interdependencies with nexus factors such as climate, water, and energy within the embeddings of a food production system. Through a Nigerian case study approach, this study attempts to bridge this gap by qualitatively investigating how organic leafy vegetable production (OLVP) and its anticipated outcomes can be affected by the interface of water, energy, and climate with food production. This was intended to generate exploratory insights that will help underscore why cross-sectoral linkages should be accounted for when deploying agricultural technology interventions. To achieve this objective, we conducted in-depth interviews and focus group discussions, and field visits to the farms of organic farmers in Ajibode, Ibadan, Nigeria. Results indicate that the productivity of OLVP was severely constrained by highly contextual nexus factors such as energy deficit, the water source for irrigation, changes in rainfall patterns, and temperature effect of harmattan. We concluded that location-specific nexus elements that intersect with food production should be accounted for when introducing productivity-enhancing technologies. Otherwise, the opportunity for improved agricultural productivity may remain elusive. Finally, our study shows that the nexus approach can help reveal intricately linked cross-sectoral factors that can constrain the performance of agricultural technologies.

Raingardens capture and filter urban stormwater using sandy soils and drought-tolerant plants. An emerging question is whether raingardens can also be used as vegetable gardens, potentially increasing their popularity and implementation. A successful vegetable raingarden will need to both retain stormwater and produce vegetables, despite potential water deficits between rainfall events. To determine whether raingardens can provide this dual functionality, we undertook a greenhouse pot experiment using two different substrates (loamy sand raingarden substrate and potting mix typical of containerised vegetable growing) and two methods of stormwater application (‘sub-surface’ and ‘surface’ watering) with the water quantity at each application determined by average Melbourne summer rainfall. Overall, potting mix produced bigger plants (biomass and leaf area) and greater yield than did the loamy sand. Yield effects were variable: tomato yield was unaffected by treatment, bean yield was greatest in potting mix, beetroot yield was greatest with sub-surface watering and parsley yield was greatest with surface watering. Bigger plants also had greater transpiration, which meant that stormwater retention was greatest for parsley and tomato plants growing in potting mix with surface watering. Although, a raingarden with potting mix and surface application of stormwater was optimal for producing food and retaining stormwater under our rainfall regime, potting mix could be problematic due to higher nutrient leaching and breakdown over time. Therefore, we recommend using a mix of loamy sand and potting mix. However, the choice of substrate and watering treatment require trade-offs between yield, stormwater retention and potential implications for water quality and long-term stability of hydraulic properties.

Irrigation water coming from freshwater bodies that suffer toxic cyanobacterial blooms causes adverse effects on crop productivity and quality and raises concerns regarding food contamination and human exposure to toxins. The common agricultural practice of spray irrigation is an important exposure route to cyanotoxins, yet its impact on crops has received little attention. In the present study we attempted an integrated approach at the macro- and microscopic level to investigate whether spray or drip irrigation with microcystins (MCs)-rich water differently affect spinach performance. Growth and functional features, structural characteristics of stomata, and toxin bioaccumulation were determined. Additionally, the impact of irrigation method and water type on the abundance of leaf-attached microorganisms was assessed. Drip irrigation with MCs-rich water had detrimental effects on growth and photosynthetic characteristics of spinach, while spray irrigation ameliorated to various extents the observed impairments. The stomatal characteristics were differently affected by the irrigation method. Drip-irrigated spinach leaves showed significantly lower stomatal density in the abaxial epidermis and smaller stomatal size in the adaxial side compared to spray-irrigation treatment. Nevertheless, the latter deteriorated traits related to fresh produce quality and safety for human consumption; both the abundance of leaf-attached microorganisms and the MCs bioaccumulation in edible tissues well exceeded the corresponding values of drip-irrigated spinach with MC-rich water. The results highlight the significance of both the use of MCs-contaminated water in vegetable production and the irrigation method in shaping plant responses as well as health risk due to human and livestock exposure to MCs.