The proliferation of food, feed and biofuels demands promises to increase pressure on water competition and stress, particularly for Thailand, which has a large agricultural base. This study assesses the water footprint of ten staple crops grown in different regions across the country and evaluates the impact of crop water use in different regions/watersheds by the water stress index and the indication of water deprivation potential. The ten crops include major rice, second rice, maize, soybean, mungbean, peanut, cassava, sugarcane, pineapple and oil palm. The water stress index of the 25 major watersheds in Thailand has been evaluated. The results show that there are high variations of crop water requirements grown in different regions due to many factors. However, based on the current cropping systems, the Northeastern region has the highest water requirement for both green water (or rain water) and blue water (or irrigation water). Rice (paddy) farming requires the highest amount of irrigation water, i.e., around 10,489 million m3/year followed by the maize, sugarcane, oil palm and cassava. Major rice cultivation induces the highest water deprivation, i.e., 1862 million m3H2Oeq/year; followed by sugarcane, second rice and cassava. The watersheds that have high risk on water competition due to increase in production of the ten crops considered are the Mun, Chi and Chao Phraya watersheds. The main contribution is from the second rice cultivation. Recommendations have been proposed for sustainable crops production in the future. (Résumé d'auteur)

The proliferation of food, feed and biofuels demands promises to increase pressure on water competition and stress, particularly for Thailand, which has a large agricultural base. This study assesses the water footprint of ten staple crops grown in different regions across the country and evaluates the impact of crop water use in different regions/watersheds by the water stress index and the indication of water deprivation potential. The ten crops include major rice, second rice, maize, soybean, mungbean, peanut, cassava, sugarcane, pineapple and oil palm. The water stress index of the 25 major watersheds in Thailand has been evaluated. The results show that there are high variations of crop water requirements grown in different regions due to many factors. However, based on the current cropping systems, the Northeastern region has the highest water requirement for both green water (or rain water) and blue water (or irrigation water). Rice (paddy) farming requires the highest amount of irrigation water, i.e., around 10,489 million m3/year followed by the maize, sugarcane, oil palm and cassava. Major rice cultivation induces the highest water deprivation, i.e., 1862 million m3H₂Oeq/year; followed by sugarcane, second rice and cassava. The watersheds that have high risk on water competition due to increase in production of the ten crops considered are the Mun, Chi and Chao Phraya watersheds. The main contribution is from the second rice cultivation. Recommendations have been proposed for sustainable crops production in the future.

Since the Bonn 2011 Conference, the Food-Energy-Water (FEW) nexus has become one of the most popular global research topics. Understanding and addressing the complex interactions between the FEW components is essential for sustainable development. This study proposes an environmental impact minimization model, which considers the FEW nexus under four climate change scenarios, to optimize the spatial distribution of three energy crops (rice, corn, and sugarcane). Life cycle assessment (LCA), linear programming, and a climate change simulation model are integrated to analyze appropriate bioenergy production rates while comparing the benefits of bioenergy with the current renewable energy policy in Taiwan. The major findings of LCA in this study indicate that electricity generation using bio-coal produced from rice straw is very beneficial to the environment. Considering the spatial characteristics of Taiwan, simulations from the spatial optimization model suggested that (a) the rice and corn cultivation areas should be increased in southern Taiwan for bio-coal and bioethanol production, in accordance with the “food and feed priority policy”; and (b) the rice cultivation area should be decreased across Taiwan, based on the “water conservation policy”. In addition, compared to solar power, the development of bioenergy can simultaneously enhance food and energy self-sufficiency.

This study aims to evaluate the performance of groundwater-based tube well irrigation systems of Sarlahi District in Nepal considering a water–energy–food nexus approach. The deep tube well (DTW) irrigation systems showed better performance over shallow tube well (STW) irrigation systems in terms of water supply and agricultural output per unit of irrigated area. On the other hand, the STW-based irrigation systems showed better performance in terms of energy use, management operation and maintenance (MOM) cost and benefit–cost ratio compared to DTW-irrigated systems. The productivity of irrigation water and energy input to major crops showed the best performance for maize followed by rice and wheat. The simulated yields of cereal crops through the AquaCrop model showed significant scope for enhancing crop yields and associated benefits through judicious use of water and fertilizer. (Résumé d’auteur)

Understanding the interconnections and tradeoffs between food, energy, and water (FEW) in grain production, which are essential for agricultural sustainability, remains an elusive yet important task. We propose a four-step analysis method for exploring potential approaches to coordinating the FEW nexus in grain production based on a conceptual framework that incorporates the impact of rural livelihood transitions and farmland resource constraints. We apply this method to a small-scale watershed in Hunan Province, China using data from land-use maps, farm household surveys, farmland quality surveys, and cropping-pattern surveys. Transitions of rural livelihoods have led farmlands to become increasingly large in scale. The combined impacts of this concentration of large-scale farms and the government subsidy policy, which favors double cropping, undermines the FEW nexus. Our findings suggest two operational approaches for coordinating the FEW nexus in rice production. One is to develop adaptive agricultural policies that support farmers whose aggregate performance on rice production is superior or more balanced. The other is to optimize cropping patterns based on the suitability of farmland for grain planting.

BACKGROUND: Quantification of spray deposition on a target crop is of vital importance to optimize pesticide application. In traditional determinations of spray deposition, a large amount of organic solvent is used to extract pesticides from the target crops. In this study, a water‐soluble food dye of Allura Red was developed as a tracer to determine pesticide spray deposition on a rice target crop. RESULTS: The addition of Allura Red does not obviously alter the physicochemical properties of pesticides (viscosity, density and surface tension) and droplet spectra. An ultra‐performance liquid chromatography (UPLC) analytical method was developed and validated to determine the deposition amount of Allura Red on rice plants. Method accuracy and precision for Allura Red were found to be satisfactory with recoveries of 96.07% to 107.48%. To validate the method, comparative deposition analyses were carried out using representative systematic and non‐systematic pesticides (nitenpyram and chlorothalonil) under the same spraying scenarios using a Potter spray tower. Allura Red and pesticides showed comparable deposition under the same application conditions with ratios from 0.98 to 1.21. A field trial using an unmanned aerial vehicle sprayer further indicated that the deposition rates for Allura Red and nitenpyram on rice seedling were 13.04% and 11.07%, with corresponding relative standard deviation values (n = 5) of 16.39% and 18.79%. CONCLUSION: A laboratory test and field trial confirmed that the developed method of using Allura Red as a tracer for spray deposition assessment is feasible and practicable. © 2019 Society of Chemical Industry

This study investigated the feasibility of using an invasive snail, Pomacea canaliculata, as a food source and water purifier for the commercial breeding of the loach Misgurnus anguillicaudatus. The predatory potential of M. anguillicaudatus (3.5–5.5 g) against hatchling snails was evaluated in aquaria and simulated paddy fields. Some hatchling snails left the water to avoid being preyed upon by the loaches, and approximately 10 hatchlings died per day in the presence of five loaches in aquaria, whereas a weaker snail control effect was observed in the simulated paddy fields. The growth of rice seedlings (Oryza sativa) was not reduced by the presence of hatchling snails alone, but the shoot biomass of seedlings coexisting with snails was promoted after introducing the loaches. Additionally, the presence of P. canaliculata adults improved the aquatic environment in the short term for loach breeding by decreasing the turbidity of the water. Importantly, M. anguillicaudatus (12–18 g) mortality decreased and its weight increased in the presence of adult snails.