Water Use Productivity Research Articles

Case Study of Effects of Mineral N Fertilization Amounts on Water Productivity in Rainfed Winter Rapeseed Cultivation on a Sandy Soil in Brandenburg (Germany) over Three Years

Detailed knowledge about farm management practices and related hydrological processes on water productivity is required to substantially increase the productivity of precipitation water use in agriculture. With this in mind, the effect of the nitrogen (N) fertilization level on water productivity of winter oilseed rape (Brassica napus L.) was analyzed using a modeling approach and field measurements. In this first study of interception loss and water productivity in winter oilseed rape, the crop was cultivated in a field experiment on a sandy soil in Brandenburg (Germany) under five nitrogen fertilization treatments with 0, 60, 120, 180, and 240 kg mineral N ha−1 a−1. Based on data from three vegetation periods the water flows and the mass-based water productivity of seeds were calculated on a daily basis with the AgroHyd Farmmodel modeling software. As recommended from the recently developed guidelines of the FAO on water use in agriculture, the method water productivity was applied and uncertainties associated with the calculations were assessed. Economic profit-based water productivity (WPprofit) was calculated considering the costs of fertilization and the optimal level of N fertilization, which was determined based on a quadratic crop yield response function. Mean water productivity of seeds varied from 1.16 kg m−3 for the unfertilized control sample to 2.00 kg m−3 under the highest fertilization rate. N fertilization had a clearly positive effect on WPprofit. However, fertilizer application rates above 120 kg N ha−1 a−1 led to only marginal increases in yields. Water productivity of seeds under the highest fertilization rate was only insignificantly higher than under medium application rates. The optimum N level for the maximal WPprofit identified here was higher with 216 kg N ha−1 a−1. The conclusion is that further research is needed to investigate the interaction between fertilization and other farm management practices.

Clay, Fire, Air, and Mostly Water: Understanding the Importance of Water Resources in Pottery Workshops in Ancient Iberia by Integrating Ethnoarchaeological, Experimental, and Archaeological Research

ABSTRACT Archaeological studies of pottery production have given little attention to the productive uses of water, building historical discourses without taking into consideration its crucial role in many chaînes opératoires. Structures related to the use of water in pottery-making, such as wells, cisterns, or settling ponds, are very rarely discussed. This article aims to remedy that situation by contributing archaeological, ethnoarchaeological, and experimental evidence of the importance of water and structures related to the use of water in large-scale pottery production in workshops in ancient and traditional Iberia. We propose recognition of the importance of water use in pottery production to develop a greater understanding of how pottery workshops have operated in diverse geographical and chronological contexts.

Effect of decision variables on yield and water productivity of onion under conventional furrow irrigation system in bako woreda, Ethiopia

Flow rate and furrow length are the main irrigation decision variables currently affecting yield and water productivity at farm level. Improper selection of these variables produces an over use of water and loss in crop production. The general objective was to investigate the effect of decision variables on yield and water productivity of onion under conventional furrow irrigation system, with specific objective to analyze the effect of flow rate, furrow length and their interaction on yield and water productivity of onion. The field experiment was laid out in randomized complete block design with factorial arrangement of three levels of flow rate (0.7, 0.98 and 1.3 L/S) and three levels of furrow length (25, 35 and 50 m) with three replications. Inflow out flow method was used to determine the infiltration characteristics of the soil and Irrigation depth was controlled by using 3-inch Parshall flume. The maximum non-erosive flow rate to the experimental site was fixed through design equation considering soil textural class and furrow bed slope. Effect of furrow length and flow rate on yield and water productivity of the onion were used for evaluation. Their analyses indicated that effect of furrow length and their interaction with flow rate on yield were not significant (p<0.05). However, the flow rate showed highly significant (p<0.01) effect on yield of onion. The ranges of mean yield gained from furrow length and flow rate were F1 (14.75 ton ha-1) to F3 (15.96 ton ha-1) and Q1 (13.59 ton ha-1) to Q3 (19.69 ton ha-1), respectively. The effect of furrow length on crop water use efficiency and field water use efficiency was not significant (p<0.05). However, the flow rate has showed highly significant (p<0.01) effect on crop water use efficiency and field water use efficiency. The range of mean crop water use efficiency and field water use efficiency from furrow length and flow rate were F1 (33.65 kg/ha/mm) to F3 (36.41 kg/ha/mm) and Q1 (30.99 kg/ha/mm) to Q3 (38.65kg/ha/mm) and F1 (2.06 kg/m3) to F3 (2.23 kg/m3) and Q1 (1.89 kg/m3) to Q3 (2.36 kg/m3), respectively. Therefore, it can be concluded that a furrow length of 50 m is suitable to use 1.3 L/S of flow rate for better onion yield and water productivity under similar soil type of study area.
 Int. J. Agril. Res. Innov. Tech. 11(1): 92-100, June 2021

Use of Phenomics for Differentiation of Mungbean (Vigna radiata L. Wilczek) Genotypes Varying in Growth Rates Per Unit of Water.

In the human diet, particularly for most of the vegetarian population, mungbean (Vigna radiata L. Wilczek) is an inexpensive and environmentally friendly source of protein. Being a short-duration crop, mungbean fits well into different cropping systems dominated by staple food crops such as rice and wheat. Hence, knowing the growth and production pattern of this important legume under various soil moisture conditions gains paramount significance. Toward that end, 24 elite mungbean genotypes were grown with and without water stress for 25 days in a controlled environment. Top view and side view (two) images of all genotypes captured by a high-resolution camera installed in the high-throughput phenomics were analyzed to extract the pertinent parameters associated with plant features. We tested eight different multivariate models employing machine learning algorithms to predict fresh biomass from different features extracted from the images of diverse genotypes in the presence and absence of soil moisture stress. Based on the mean absolute error (MAE), root mean square error (RMSE), and R squared (R2) values, which are used to assess the precision of a model, the partial least square (PLS) method among the eight models was selected for the prediction of biomass. The predicted biomass was used to compute the plant growth rates and water-use indices, which were found to be highly promising surrogate traits as they could differentiate the response of genotypes to soil moisture stress more effectively. To the best of our knowledge, this is perhaps the first report stating the use of a phenomics method as a promising tool for assessing growth rates and also the productive use of water in mungbean crop.

Ecological Significance of Residues Retention for Sustainability of Agriculture in the Semi-arid Tropics

In South Asia, land degradation is primarily a monsoon mediated phenomenon restricted to 2-3 rainy months. The overall strategy for land degradation neutrality should (i) favour actions that keep soils covered with residues and (ii) plant kharif (rainy season) crop before the onset of monsoons to provide soil cover. Retention of anchored residues provides surface cover, increases microbial activity, carbon sequestration, and availability of nutrients. Surface retained residues reduce root zone salinization, detoxify phytotoxic monomeric Al in acidic soils and enhance the potential for use of brackish ground water in crop production. Residues covers save irrigation water and overcome the ill effects of poor agronomic and water management practices. Early direct dry seeding in surface retained residues has the potential of making kharif season planting independent of the onset of monsoon rains in South Asia and helps reduce acreages of Kharif and Rabi fallow lands. For improving carbon content in Indian soils, perhaps the most important priority is to devise tillage and crop residue management approaches that promote in situ rain water storage and its use for growing more crops. The paper summarises how crop residues fuel and drive soil functions and related ecosystem services and plant growth.

The effect of water level in vertical aquaculture systems on production performance, biochemistry, hematology, and histology of Anguilla bicolor bicolor

The water level in the cultivation of eel (Anguilla bicolor bicolor) is an important study in order to provide the optimal water level for cultivation. Optimizing the water level will affect the substitution of respiration energy with energy to grow. In addition, the water level information is related to the efficiency of water use for eel production in the future. Information on water level for eel production is still very limited, so this research is necessary to do. A total of 120 eel elver (initial weight 13.66 ± 0.09 g) were collected from eel companies in Bogor City, Indonesia. Fish were reared in vertical aquaculture systems with a stocking density of 10 fish per container for 60 days. The artificial feed containing 55% protein given as much as 3–5% of the biomass. Absorption and water replacement were done 20% per day. The result of this research showed that fish weight increased with an average of 33.45 ± 0.33 g. Different water levels had an impact to KKb, SGOT, ALP, and He. There was erosion of the skin epidermis and necrosis of the gill filaments due to the adaptation process. Water quality was within the optimum range for all treatments and 1.5 cm water level is recommended for maintenance (SGOT, ALP and He values were closest to normal values).

Spray irrigation with microcystins-rich water affects plant performance from the microscopic to the functional level and food safety of spinach (Spinacia oleracea L.)

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.

Análise da importância do reuso da água em lavanderias de beneficiamento de jeans

As lavanderias de Beneficiamento de Jeans, são consideradas indústrias com uma alta capacidade poluidora e hidro intensivas, devido aos produtos químicos utilizados durante os processos produtivos, e que demandam uma grande quantidade de água para o beneficiamento das peças. Nesse cenário há necessidades de estudos que apontem alternativas de reuso da água, como também diversificação na sua forma de captação. A presente pesquisa tem como objetivo analisar o reuso de águas nas lavanderias localizadas no Arranjo Produtivo Local de Confecções do Agreste Pernambucano (APLCAPE), de forma a contribuir para as alternativas de reuso durante o processo produtivo. Para levantamento dos dados, foram aplicados questionários e entrevistas em 105 lavanderias, onde foi possível determinar e conhecer o processo produtivo, uso da água e possibilidades de reuso. Verificou-se que 83% das lavanderias realizam níveis diferentes de reuso água e 17% não fazem qualquer tipo de reuso. Não obstante, os resultados demostraram que a prática do reuso de água, além de contribuir para a economia de água no processo, traz uma economia financeira considerável, uma vez que a maioria das lavanderias utilizam água compradas de caminhão pipa, o que interfere no custo e na competividade do produto.

The water use of heating pathways to 2050: analysis of national and urban energy scenarios

Sustainable energy systems can only be achieved when reducing both carbon emissions and water use for energy generation. Although the water use for electricity generation has been well studied, integrated assessments of the water use by low-carbon heat systems are lacking. In this paper we present an analysis of the water use of scenarios for heat and electricity production for the year 2050 for the Netherlands and its capital, Amsterdam. The analysis shows that (i) the water withdrawal for heating can increase up to the same order of magnitude as the current water withdrawal of thermoelectric plants due to the use of aquifer thermal energy storage, (ii) the virtual water use for heating can become higher than the operational water consumption for heating, and (iii) the water use for electricity production becomes a relevant indicator for the virtual water use for heat generation because of the increase of power-to-heat applications.

Increasing the Productivity and Efficiency of Water Use by Reserving Water

One use of technology in agriculture involves setting up a reserving sheet for subsurface moisture under the root zone of wheat crops, which is symbolized by SWRT, to conserve the water in the root zone. This reduces the field water losses by raising the efficiency of water use (WUE) and economical water productivity (EWP). For this study, an SWRT membrane sheet was put under the root zone of wheat crops throughout the growing season, from the winter of November 2019 to the end of the season in April 2020, in a free field. The study was conducted on a private farm located in the province of Babylon in Sadat Al-Hindya Town, which is approximately 70 km from the capital (Baghdad). Surface irrigation was utilized for the irrigation of the wheat crops. Two methods were used: method A1 utilized the SWRT sheet and method A2 was conducted without the SWRT sheet. The irrigation water supply, irrigation period, and soil water content before and after irrigation were computed and recorded every day for the A1 and A2 methods. The values of wheat crop production (yield), water use efficiency, and economical water productivity from the two plots were computed and compared. The results obtained for water use efficiency for the two methods, A1 and A2, were 0.51 and 0.47 kg/m3, respectively. The increment in yield of plot A1 compared with plot A2 was 6.45%. The increment in WUE of plot A1 compared with plot A2 was 8.55%. In addition, the WP of the wheat crop for plots A1 and A2 were 144.44 and 119.16 ID/m3, respectively, while the increment in WP of plot A1 compared with plot A2 was 21.21%. The findings show that the SWRT method prevents the environmental effects of pesticide and fertilizers that enter the groundwater and pollute it. This technology assists in saving water and plant nutrients, and prevents pollution of the groundwater from pesticides and excess fertiliser.

Variations of groundwater storage in different basins of China over recent decades

As an important freshwater resource, groundwater is of great significance to agriculture, industry, and daily life. The investigation of groundwater storage (GWS) in different regions of China is critical for water resource management and conservation. However, previous studies used different methods and data to monitor GWS in different regions of China, which made their results difficult to compare and cross validate. Here, we used a unified method by the Gravity Recovery and Climate Experiment (GRACE) satellite data and global models to study the variations of GWS in 10 major basins in China from April 2002 to December 2016. Results showed that GWS in the i) Songhua River basin (SRB), Liao River basin (LRB), Haihe River basin (HRB), Yellow River basin (YRB), Huaihe River basin (HHRB), and southeast basin (SEB) exhibited decreasing trends, ii) Yangtze River basin (YZRB) and Pearl River basin (PRB) presented increasing trends, and iii) southwest basin (SWB) and continental basin (CB) displayed both decreasing and increasing trends during the study period. These results were validated by comparing them with a large number of previous studies, which revealed that they were accurate and reliable. Comparing with the climate data and bulletin data, the analysis of causes for these trends indicated that drought and irrigation water-use led to a decline in GWS in several basins of northern China. The decreasing trend of GWS in the SEB was related to water use for production, whereas groundwater recharge from precipitation drove the increasing trends of GWS in the YZRB and PRB. In contrast, the wide geographical areas and complex factors of the SWB and CB led to the increasing–decreasing trends of GWS. This study enriches the GWS for China over the past decade, especially for SEB, PRB, and CB with rare GWS information. It will be helpful for the country’s groundwater resource management and systematic water conservation.

Mapping incentives for sustainable water use: global potential, local pathways

Competition for freshwater resources is intensifying water scarcity and its impacts on people, economies, and the environment, posing a growing challenge for sustainable development. Meeting these challenges will require incentives to encourage sustainable water use. Prior calls to shift from supply-driven solutions to a soft path of demand management (pricing, markets, behavioral changes) have encountered stubborn obstacles. We undertake a multi-scale assessment of water reallocation and investment in water conservation technologies to understand their potential and limits for addressing different drivers of water scarcity. Our model identifies what drives water scarcity at the subbasin scale, and examines two prominent responses to these drivers. Our analysis distinguishes different types of water scarcity based on the demands for water and their timing, creating nine (9) categories of water competition, which can overlap. Water demand within agriculture contributes to scarcity in 94% of the basins experiencing scarcity, concentrated in central USA, Spain, and India. Urbanization has led to competition between cities and agriculture in 1,596 of 3,057 subbasins (52%). We examine how different institutional mechanisms (incentive-based water reallocation) and technologies (investment in water conservation technologies) can address these different types of water scarcity. This study builds on several local and high-resolution models demonstrating the potential to increase the economic efficiency (and marginal productivity) of water use. The gap between potential and implementation is high, however. Efforts to bridge this gap in priority geographies can link modelling advances with the design of pathways that combine incentives with robust water accounting, caps on water extraction, and enforcement capacity at multiple scales.

Intelligent, Nano-fertilizers: A New Technology for Improvement Nutrient Use Efficiency (Article Review)

Nano fertilizers are essential resources in agriculture in order to increase crop production, quality, productivity, and boost nutrient uptake. Nano-fertilizer is efficient for specific use of nutrients at appropriate time of plant growth and can provide nutrients as a whole with the crop. Growing crops with heavier fertilizer concentrations further increases may be limiting to crop growth due to nutrient toxicity. Nano-fertilizers provide more area for photosynthesis, leading to more sunlight absorption and greater yields of the crop. It will help plants survive challenging environmental factors such as drought. Limitations in agricultural land and water supplies can improve production land and water use productivity through the use of new technologies. Nanotechnology has the potential of transforming both personal use and development. Nanostructured formulations may also be developed in order to deliver active ingredients in response to environmental cues and biological demands more properly. The principle of fertilizer use is known to use less resource and to be free from chemical side effects. Nanotechnology has enormous potential to contribute significantly to sustainable agricultural production, particularly in developing countries.

The water use for batik production by batik SMEs in Jarum Village, Klaten Regency, Indonesia: What are the key factors?

The Indonesian batik is a potential product to support the economy of Indonesia. In spite of its potential in supporting the economy of Indonesia, the water pollution caused by batik production by Small & Mediuam Enterprises (SMEs) needs to be addressed, as it leads to water scarcity since the batik production tends to consume a huge quantity of water. This research was conducted to identify key factors that influence water use for batik production among batik craftsmen, and explain those factors using the concept of circular economy. This study was conducted using qualitative method through focus group discussion (FGD) and in-depth interview as data collection strategies and quantitative data collected as secondary data. Our study found that some practices of the batik craftsmen have shown to fit to the circular cycle, although the dischargement of wastewater into waterways still fits to the linear model. Using secondary data, the direct water use for batik production were varies from 3.33 L/pc to 235 L/pc, depending on the craftsmen. If water footprint approach is to be used, the water use will be much higher. Finally, four key factors affecting the water use are discussed in this study and efforts that can be proposed to reduce the ratio water/product as well as maintaining water as a resource, as indicated by circular economy.

Financial Feasibility of Water Conservation in Agriculture

AbstractGlobal water use for food production needs to be reduced to remain within planetary boundaries, yet the financial feasibility of crucial measures to reduce water use is poorly quantified. Here, we introduce a novel method to compare the costs of water conservation measures with the added value that reallocation of water savings might generate if used for expansion of irrigation. Based on detailed water accounting through the use of a high‐resolution hydrology‐crop model, we modify the traditional cost curve approach with an improved estimation of demand and increasing marginal cost per water conservation measure combination, adding a correction to control for impacts on downstream water availability. We apply the method to three major river basins in the Indo‐Gangetic plain (Indus, Ganges and Brahmaputra), a major global food producing region but increasingly water stressed. Our analysis shows that at basin level only about 10% (Brahmaputra) to just over 20% (Indus and Ganges) of potential water savings would be realized; the equilibrium price for water is too low to make the majority of water conservation measures cost effective. The associated expansion of irrigated area is moderate, about 7% in the Indus basin, 5% in the Ganges and negligible in the Brahmaputra, but farmers' gross profit increases more substantially, by 11%. Increasing the volumetric cost of irrigation water influences supply and demand in a similar way and has little influence on water reallocation. Controlling for the impact on return flows is important and more than halves the amount of water available for reallocation.

Ecosystem-level water use efficiency and evapotranspiration partitioning in conventional till and no-till rainfed canola

Accurately determining productive water use (i.e., transpiration, T, component of evapotranspiration, ET) is crucial to improve ecosystem water use efficiency (EWUE) and develop water-saving management practices. High frequency (10 Hz) eddy covariance data for the 2016–2017 growing season (November 2016 – May 2017) for conventional till (CT) and no-till (NT) canola (Brassica napus L.) fields were analyzed to partition ET into T and evaporation (E) using Flux Variance Similarity method. The objectives of this study were to determine and compare seasonality of T and T/ET ratios, and compare EWUE based on different metrics of carbon (gross primary production, GPP and net ecosystem production, NEP) and water vapor (ET and T) fluxes in CT and NT canola fields. Canopy stands, fluxes, and EWUE were similar until winter in both fields, but were substantially lower in NT field from February to April due to differences in recovery of canola stands after winter dormancy. However, differences were much smaller for water loss than carbon gain. Larger difference was observed for T than ET due to significant amounts of E during rainy periods under both dense (CT field) and sparse (NT field) canopies. The growing season average T/ET ratio was identical (~0.70) in both fields. The EWUE was ~23% higher in CT and ~26% higher in NT field based on T than ET for a dry period during peak growth. In comparison, EWUE was ~36% higher in CT and ~58% higher in NT field based on T than ET for a wet period during peak growth due to relatively higher loss of soil E from sparse canopy. The results not only illustrated discrepancies in EWUE based on ET and T for cross-site comparisons but also highlighted the added value of T estimates over ET for more meaningful EWUE estimates during the periods of higher E.

Water-land tradeoffs to meet future demands for sugar crops in Latin America and the Caribbean: A bio-physical and socio-economic nexus perspective

Replacing traditional fossil fuel with bioethanol has been adopted in many countries to reduce carbon emissions and achieve climate mitigation targets. However, the soaring global demand for food and bioethanol in the future may impose heavy environmental pressure on major sugar crops producing regions of Latin America and the Caribbean (LAC) through significant changes in land and water uses. Irrigation expansion in the rainfed dominant cropping areas would partially slow down the land use expansion by boosting yields, but require large-scale investments. This study assesses the future land and water demand triggered by sugar crops expansion from the food-energy-water/land nexus perspective through coupling the Global Agro-Ecological Zones model (GAEZ) with Multi-Regional Input-Output (MRIO) analysis. We further analyse the tradeoffs between water and land use under future scenarios of climate change and socio-economic development regarding to the expected goals of biofuel policies and irrigation expansion strategies in LAC countries due to sufficient local water resources. The results show that the projected water and land demand of sugar crops in LAC would increase by 198% and 205% from 2014 to 2040. Increasing the low- or non- irrigated area up to 50% would mitigate the yield loss and reduce the land demand by 10%, with limited impact on the local water resources in most LAC countries. Major bioethanol producers with limited water demand compared with available water resources, such as Brazil and Argentina, could further promote irrigation to avoid significant landuse change and benefit other countries’ land ecosystems via inter-regional bioethanol trade. While in potential higher water stress countries, including Dominican Republic, El Salvador, Guatemala and Mexico, under bioenergy orientated policy in 2040, reducing biofuel policy targets or importing bioethanol from resource rich countries would be a better option. These results could provide guidelines to balance sugar crops production and sustainable water and land use strategies across LAC.

Decomposing drivers of changes in productive and domestic water use based on the logarithmic mean Divisia index method: a regional comparison in Northern China

Abstract It is crucial to consider regional heterogeneity while analyzing drivers of changes in sectoral water use for developing differentiated and effective demand-regulation strategies in China. By using the logarithmic mean Divisia index method, this study compares dynamic influences of intensity, structure and scale factors on changes in productive and domestic water use during 2003–2017 between Tianjin (a socio-economic developed region) and Hebei (less-developed). The results show that the scale effect stimulated the growth of productive water use in both regions, while structure and intensity effects restrained such growth. The three effects all stimulated the growth of domestic water use in most years in both regions. In both regions, the largest contributor to changes in productive and domestic water use was the scale and intensity effect, respectively. However, in the two regions, the synergies of three effects resulted in different change trends of productive water use, and cumulative contributions of sub-sectors to the intensity, structure and scale effects were not exactly the same. Tianjin and Hebei need to keep on adjusting industrial structure and lowering water-use intensity to control future growth of productive water use and take strict measures to tackle the increasing trend of domestic water use but should have different policy implementation focuses.

Using DSSAT model to simulate water management practices on soybean under different soil types

Water management plays a crucial role in optimizing plant growth and production. The amount of water supplied and the timing of its application are the keys of irrigation management. The right irrigation system will result in optimal crop production and high water use efficiency (WUE). Modeling in DSSAT (Decision Support System for Agrotechnology Transfer) software can simulate the effect of water management on various types of plants. The study in this paper aims to find out the effect of water management systems on soybean in two types of soil with simulation. This study conducted descriptive quantitative methods. Combination between all irrigated systems and Tha tum type soil (AITT000001) obtained the highest yield due to soil texture, loam better than sand on water holding capacity. The highest WUE was reached the automatically irrigation system, both in the Tha Tum and IBSB910015 soil type. It means automatically irrigation system more precise than others.

Water and food utilization efficiencies in sheep and their relationship with some production traits

• The use of water by sheep needs more attention from researches and sheep breeders. • Residual water intake (RWI) is a new trait for sheep selection. • Residual feed and residual water intake is a new trait for sheep selection. • Sheep more efficient in water use are more efficient in food use. • Sheep more efficient in water and food use are desirable in a sustainable industry. The objective of this study was evaluate the efficiency in water and food use in sheep production, using two new traits (residual water intake - RWI; residual feed and residual water intake - RFRWI). For this purpose, we evaluated the relationships between the traits total water intake, RWI and RFRWI with water measures, productive performance and carcass traits (ultrasound). We used 32 lambs with age of 3 months: 16 Santa Ines breed (8 males and 8 females) and 16 crossbred 7/8 Dorper x Santa Ines (8 males and 8 females). They were fed at an automated feed and water station (Intergado®), where the food and water intake by each animal was measured automatically. Residual water intake (RWI), residual feed intake (RFI) and residual body weight gain (RWG) were calculated using the MIXED procedure in SAS®. Correlation coefficients between total water intake (TWI), RWI and all traits (water measures, performance and carcass traits) were calculated using the CORR procedure (P ≤ 0.05). Total water intake showed mean 3.15 L/day during the study and the RWI ranged from 0.66 L to -0.89 L, which represents a difference of 1.55 L between the most and least efficient animal. There was positive correlation between less efficient animals in water consumption (positive RWI) and water intake (r = 0.31); total water intake in relation to dry matter intake (r = 0.36); total water intake in relation to mid-trial metabolic body weight (r = 0.26); residual feed and residual water intake (r = 0.99) and gain/feed ratio (r = 0.44). There was negative correlation between less efficient animal and dry matter intake in relation to body weight (r= -0.33) and feed conversion ratio (r= -0.44). The evaluation of the new variables, RWI and RFRWI, proved effective in identifying the most efficient animals in water use. Moreover, these findings open the possibility of considering the traits RWI and RFRWI in sheep selection, because performance and carcass traits are not adversely affected by selecting for these new traits.