During winter in southern Queensland, eight rusa deer stags aged 4 years were given ad libitum lucerne (Medicago sativa) hay and confined in individual metabolism pens for 26 days. Stags ate 2.04 kg dry matter (DM) per day and drank 6.4 kg water per day, while the drinking water : food DM ratio was 3.3 l/kg. In experiment 2, seven rusa stags were given ad libitum lucerne hay or oaten (Avena spp.) hay with or without barley grain supplementation (200 g/day) for 56 days (four periods). This experiment was conducted from 26 July to 19 September 2001, when the stags were exhibiting the behaviour characteristic of the rut. Rusa stags ate 1.19 and 1.17 kg DM per day of lucerne and oaten hay respectively. Rusa stags given oaten hay drank slightly more water than those that received lucerne hay (5.34 and 4.47 kg/day, respectively). The drinking water : food DM ratios were 3.81 and 4.67 kg/kg for lucerne and oaten hay, respectively. Barley grain supplementation (200 g/day) had no influence on total food or water intakes of the rusa stags.

Irrigated agriculture is the backbone of Central Asian economies. Therefore, efficient irrigation water management is of crucial importance to the sustainable crop production in the region. Presented here are two studies aiming to improve agricultural water productivity â?? ET-based irrigation scheduling in Uzbekistan; and valuation of ecosystem services in Kazakhstan. The ET-based irrigation scheduling method has potential to replace subjective daily water management decisions at Water Users Association level with crop water demand-based decisions to improve water-use efficiency. Results from a two year study show that there can be a 32-35% saving of water when irrigation is applied using the ET-based scheduling method. The pilot plots are representative of 38% of irrigated area in Fergana Valley (241,407ha) and 50% in Khorezm (137,500ha) area. If this methodology is widely adopted, large amounts of water can be saved which can be diverted for other purposes. Flood irrigation of cotton is practiced on 128,000ha in the Bugunski Reservoir watershed of Kazakhstan. This practice is unsustainable due to seasonal unavailability in water supply and depletion of river discharges that were historically important at maintaining water levels downstream in nearby wetlands and the Aral Sea. Farmer surveys were used along with RIOS and SWAT modeling to evaluate alternative irrigation practices and cropping systems that can conserve water from the Bugunski Reservoir while maintaining farmer incomes. Simulations show significant reductions in irrigation water demand in the alternative scenario relative to the baseline scenario. Under baseline flood irrigation of cotton, annual irrigation demand was 928 MCM/yr averaged over the 32 year climatic record simulated. Irrigation demand decreased by 38% to 573 MCM/yr when 40,439ha of flood irrigated cotton was converted to drip irrigated cotton, sprinkler irrigated alfalfa and drip irrigated grapes. This represents a savings of 355 MCM/yr in water extracted from irrigation canals and groundwater wells | Vinay Nangia. (7/11/2016). Managing Scarce Water Resources in Irrigated Agri-Food Systems of Central Asia Two Case Studies. Phoenix, United States: American Society of Agronomy.

M. Blümmel, M. Samad, O. P. Singh, T. Amede, 'Opportunities and limitations of food - feed crops for livestock feeding and implications for livestock - water productivity', The Rangeland Journal, vol. 31(2), p.207, CSIRO Publishing, 2009 | The paper discusses the contribution of crop residues (CR) to feed resources in the context of the water productivity of CR in livestock feeding, using India as an example. It is argued that crop residues are already the single most important feed resource in many livestock production systems in developing countries and that increasing their contribution to livestock feeding needs to be linked to improving their fodder quality. Using examples from multi-dimensional crop improvement, it is shown that CR fodder quality of key crops such as sorghum, rice and groundnut can be improved by genetic enhancement without detriment to grain and pod yields. Improving crop residue quality through genetic enhancement, agronomic and management interventions and strategic supplementation could improve water productivity of farms and systems considerably. The draw-backs of CR based feeding regimes are also pointed out, namely that they result in only moderate levels of livestock productivity and produce higher greenhouse gas emissions than are observed under feeding regimes that are based on high quality forages and concentrates. It is argued that feed metabolisable energy (ME) content should be used as an important determinant of livestock productivity; water requirement for feed and fodder production should be related to a unit of feed ME rather than feed bulk. The paper also revisits data from the International Water Management Institute (IWMI) work on livestock?water productivity in the Indian state of Gujarat, showing that water input per unit ME can vary several-fold in the same feed depending on where the feed is produced. Thus, the production of one mega joule of ME from alfalfa required 12.9 L of irrigation-derived water in south Gujarat but 50.7 L of irrigation-derived water in north Gujarat. Wheat straw in south Gujarat required 20.9 L of irrigation-derived water for 1 MJ ME and was in this instance less water use efficient than alfalfa. We conclude that water use efficiency across feed and fodder classes (for example crop residue v. planted forages) and within a feed is highly variable. Feeding recommendations should be made according to specific water use requirement per unit ME in a defined production system

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.

With growing populations and changing climate, the food, energy and water (FEW) security have become a global issue. In response, the concept of FEW nexus in which the interdependency between FEW sectors are taken into account in order to effectively manage the resources and provide FEW security has emerged. Thus, in order to understand the interdependency between FEW sectors a thorough quantitative framework is necessary. Although there are numerous studies on FEW nexus, there is limited research on developing mathematical equations to model the FEW nexus. The goal of this study was to develop an input-output (IO) model to quantify the interdependency between FEW sectors in the Pacific Northwest. The FEW sectors were divided into 21 subsectors and IO model was used to quantify the total output of each subsector. Intensity coefficients were calculated and further broken down to technology coefficients and allocation coefficients. The uncertainty analysis was used to quantify the effect of variation in technology coefficients and allocation coefficients on output of each subsector and the results showed that these two distributions are significantly different. The results of sensitivity analysis showed that agricultural crops, especially alfalfa has the highest sensitivity to water and energy consumption due to the fact that alfalfa production is energy and water intensive. The multi-objective optimization was used to minimize the cost and environmental impact of FEW system and the results showed that in order to minimize the cost and environmental impacts, more surface water and hydroelectricity and wind electricity should be utilized.

With the implementation of the “Grain-for-Green” program, artificial vegetation was introduced on the Loess Plateau, which resulted in high soil water content (SWC) depletion. Currently, lack of soil water recharge is one of the most serious challenges on the Loess Plateau. Soil drying and wetting processes are critical for the sustainability of soil water recycling, but this has not been well studied. There is also a lack of physical definition of the upper bound SWC of dried soil layers (DSL). In this study, soil water dynamics – the change of SWC affected by precipitation and vegetation transpiration – were studied under converted vegetation. In-situ SWC measurements from the 0–5 m or 0–8 m deep profile over consecutive wet years (from 2016 to 2018 with an average precipitation of 660.9 mm) were analyzed to understand soil water depletion and restoration processes. Results showed distinct differences in soil water dynamics in the soil profiles and soil water balances under different vegetation types. SWC under continuous perennial alfalfa (Medicago sativa) had greater fluctuations between 0 and 300 cm than below 300 cm, and a DSL was observed below 300 cm. After converting from alfalfa to soybean (Glycine max), SWC increased greatly during the three wet years. Soil water storage (S) increased at an average rate of 35.8 mm year⁻¹ m⁻¹ within the top 500 cm of the soil profile, average evapotranspiration (ET) was 482.0 mm year⁻¹, and maximum restoration depth of soil water extended to 660 cm. However, SWC gradually decreased over time after replacing food crop with alfalfa. S declined at an average rate of 21.4 mm year⁻¹ m⁻¹ within the top 500 cm of the soil profile, average ET was 680.4 mm year⁻¹ and the maximum depth of soil water depletion extended to 360 cm. These results suggest that SWC in deep layers can be depleted and replenished quickly, and the processes were dominated by vegetation types and precipitation. Taking vegetation types and soil texture into consideration, the calculation of upper bound SWC of DSL was redefined. Given the long-term effects of high water demand from vegetation such as alfalfa on the soil water balance, ET of vegetation should be reduced through conversion to less water-intensive vegetation types or biomass control (i.e. reduced planting density appropriately) in arid areas of the Loess Plateau.

Although standardized sediment toxicity testing methods have been developed for the amphipod Hyalella azteca, no standardized chronic water‐only toxicity testing methods have been established. Furthermore, optimal feeding and water quality conditions for culturing and toxicity testing with this species remained unclear. The objective of the present study was to determine the food or combination of foods that best promotes survival, growth, and reproduction of the US Lab strain of Hyalella azteca under 42‐d, water‐only, static‐renewal testing conditions. The authors conducted 7 42‐d control (no toxicant) tests with various combinations of food (including Tetramin, yeast–cereal leaves–trout chow, diatoms, wheatgrass, alfalfa, and maple leaves) and substrate types (clean “unconditioned” Nitex screens vs “conditioned” Nitex screens that were colonized by live biofilms). Over all treatments, survival ranged from 18% to 96%, dry weight per individual from 0.084 mg to 1.101 mg, and reproduction from 0 young/female to 28.4 young/female. Treatments that included Tetramin tended to result in better performance than those that did not. In particular, treatments that included Tetramin and either conditioned screens or diatoms consistently had high survival, weight, and reproduction values as well as low variability among replicates (measured as coefficient of variation). A ramped Tetramin plus diatom suspension feeding regime appears to have the greatest potential to produce consistently good performance across laboratories using static‐renewal systems. Environ Toxicol Chem 2016;35:2407–2415. © 2016 SETAC