Cost Of Irrigation Water Research Articles

Internalizing the carbon footprint in rice cultivation through solar irrigation - an economic study in Villupuram district of Tamil Nadu, India

This study attempts to highlight the comparative economic and environmental advantages of solar powered irrigation in terms of cost, energy and carbon footprint over the existing electric operated pumping system in rice cultivation. Multi-stage and snowball sampling methods were used in this study. This study was conducted in Villupuram district of Tamil Nadu purposively, as the district has the largest number of energized pumps adopted for irrigation in the state and it will be considered as a second stage. The total sample size of 90 was allotted with a quota of 45 each under electric operated well (EOW) and solar operated well (SOW) category. The cost of irrigation water, energy and carbon footprints were indirectly assessed in this study using some imputation procedures. The hours of irrigation were higher in the case of solar due to lesser horse powered motors and energy rationing is not the binding constraint in SOW unlike EOW. The per liter cost of water output was higher in the case of electric with subsidy and same was higher in the case of solar in without subsidy scenario comparisons. The hours of pumping and imputed energy consumption were higher for rice in the case of SOW compared to EOW. The energy consumption per ha decreased with increasing HPs both in the case of SOW and EOW due to economies of scale operation. The inclusion of social carbon cost in the economic analysis showed that the net income in SOW was higher without any compromise in rice production. In with social carbon cost / benefit scenario, the irrigation cost share was lesser in SOW compared to EOW. Hence it was construed that the SOW internalize the carbon footprints and serve as an important mitigating tool in confronting upcoming climate change risks. The policy makers must pay attention in promoting the subsidized SOW in agriculture, considering the negative and positive externalities involved in these two sources of irrigation.

The formation of a crop of fodder and semi-sugar beet under irrigation in conditions of global warming

Relevanse. To reduce the negative impact of drought on the production process of agrocenoses of field crops, the entire complex of agrotechnical and reclamation measures should be used to ensure increased drought resistance of crops in the structure of crop rotations for various purposes.The purpose of our research was to study the dynamics of the growth of the raw mass of root crops and the collection of dry matter by the periods of growth and development of fodder and semi-sugar beet at different moisture levels of the root layer of the soil.Material and methodology. The research was carried out in a specially built arid zone, which is a 3x20 m plot, isolated from soil moisture to a depth of 1.5 m by a clay castle along the periphery and a dense reinforced polyethylene film between the variants. The arid area was divided into four plots, each with an area of 15 m2 (3x5 m), in which a different level of moisture supply was maintained throughout the growing season. The variety of fodder beet Eckendorf yellow and semi–sugar beet – Semi-sugar pink variety were used as the object of research.Results. It has been established that at all values of humidity, the maximum accumulation of the raw mass of root crops in both varieties was noted in the second period of growth and development of plants, which lasts an average of 60 days and lasts from the beginning of closing of crops in rows to the beginning of opening in row spacing. Among the studied irrigation regimes, the option should be recognized as optimal, where during the growing season the relative humidity of the root layer at a depth of 1 m is maintained at the level of 70-75% of the WPV. With such moisture, the yield of root crops for fodder beet is 855 centners/ha, for semi-sugar beet – 679 centners/ha, and the collection of dry matter – 120.54 and 156.33 centners/ha, respectively. With a further increase in humidity to 75-80% of the FPV, the increase in yield and collection of dry matter per 1 ha of crops for both beet varieties is within the statistical error of the experiment, however, the cost of irrigation water for the formation of 1 q of dry matter increases by an average of 2.2 times, which negatively affects the cost of grown products. It has been proven that the optimal regime of soil moisture is provided by the irrigation scheme according to the periods of growth and development of plants 1 3 1; irrigation rate – 400 m3/ha, irrigation rate – 2000 m3/ha.

Uticaj režima navodnjavanja i organskog đubrenja na uljanu repicu u polusušnom području

Climate changes and the cost of irrigation water in semi-arid areas seriously reduce the availability of water for irrigation. The optimal allocation of water resources to irrigation and limit water overexploitation are necessary in these regions. A field trial aimed to evaluate irrigation regimes (60, 80, and 100% based on field capacity, abbreviated as FC60, FC80 and FC100) and organic fertilizer (0, 15, and 30 t ha-1 farmyard manure, abbreviated as FYM) on two rapeseed varieties (Hydromel and Nathalie) in the semi-arid region of Qazvin, Iran. The highest lateral growth (branch number) was observed in the Hydromel cultivar with the application of 15 and 30 t ha-1 farmyard manure (FYM30 and FYM15) under FC100 and FC80 conditions. Comparison of lateral growth between the cultivars showed that Nathalie cultivar was less affected by FYM and irrigation. The chlorophyll content decreased under FC60; however, no significant difference was observed between FC80 and FC100. The maturity of Nathalie was earlier than that of Hydromel. However, the use of FYM significantly extended the days to maturity in Hydromel. Although the silique length of the Nathalie cultivar was 13% less than Hydromel, this component significantly decreased in Hydromel under water deficit conditions (FC80 and FC60). The highest number of siliques was recorded in the Hydromel under FYM30+FC100 and FYM30+FC80. The 60% irrigation regime caused a significant reduction in the number of siliques. Although the seed yield of Hydromel was higher than that of Nathalie, the stability of the seed yield in Nathalie was more evident under FC80 and FC60. Overall, the obtained results showed that the Hydromel variety can produce an acceptable yield under FYM30+FC80 and save 20% in water consumption. The results indicated that the 60% irrigation regime was a stressful deficit irrigation and cannot be recommended for this semi-arid region.

ВОДОПОТРЕБЛЕНИЕ, УРОЖАЙНОСТЬ И КАЧЕСТВО ЛУКА РЕПЧАТОГО В ЗАВИСИМОСТИ ОТ ПРИМЕНЕНИЯ ГУМИНОВЫХ УДОБРЕНИЙ ПРИ КАПЕЛЬНОМ ПОЛИВЕ В САРАТОВСКОМ ЗАВОЛЖЬЕ

Purpose: to study the features of humic fertilizer impact on water consumption, yield and quality of onions under drip irrigation in the dry-steppe zone of Saratov Trans-Volga region. Materials and methods. Field studies were carried out on dark chestnut soils in 2019–2022. The objects of the study were the zoned Chalcedony variety and fertilizers based on humic acids. Related observations and studies of water consumption, productivity formation and yield quality were carried out using generally accepted methods. Results. Research has shown that when maintaining a drip irrigation regime, which involves watering when soil moisture is reduced to 80 % of the lowest moisture capacity in the 0–30 cm layer, the total water consumption of onions on average over the years of the study amounted to 4102 cub. m/ha, average daily – 31 cub. m/ha. The humic fertilizer application contributed to a more economical use of moisture and irrigation water, as evidenced by a decrease in the water consumption coefficient by 7.1–23.3 %, and the cost of irrigation water to form a unit of marketable output by 15.9–24.0 %. Humic fertilizers also provided a significant yield increase – 4.9–15.31 t/ha (10–31 % higher than the control – without fertilizers). Conclusions: the humic fertilizer application, which have stimulating and adaptogenic features, when growing onions under the arid conditions of the Saratov Trans-Volga region with drip irrigation, is an effective technique that ensures more economical use of water resources and increases the yield of one of the leading vegetable crops – onions.

Determination of the yield, enzymatic and metabolic response of two Capsicum spp. cultivars to deficit irrigation and fertilization using the stable isotope 15N

BackgroundClimate change is increasingly impacting agriculture all over the world, with extended periods of drought, flooding, hail, winds and temperature extremes. To negate the effects of climate change, researchers are trying to find new agricultural production techniques, to save resources without losing yield quality and quantity. A study on Capsicum annuum L. 'Chili-AS Rot' and Capsicum chinense Jacq. 'Naga Morich' chilies, grown under field capacity, deficit irrigation (50% field capacity) and full and half dose of mineral fertilizer in peat soil substrate was conducted. Both cultivars were marked with the stable isotope 15N, to follow nitrogen translocation in chili plants under stress conditions.ResultsThe yield and plant biomass, capsaicin synthase (CS), phenylalanine ammonia lyase (PAL), and peroxidase (POX), as well as total and individual capsaicinoids were studied. In 'Chili-AS Rot' the deficit irrigation with the full-fertilization (Diff) dose showed the highest yield and fruit number, compared to other treatments. In the 'Naga Morich' cultivar the deficit irrigation and half-fertilization (Dihf), showed the highest yield, fruit number and dry weight of chilies, compared to other treatments. In the cultivar 'Chili-AS Rot', deficit irrigation was found to reduce the utilization of N fertilizer when the plant (leaves, stems, and roots) and fruit were considered. The utilization of nitrogen fertilizer was 60 to 70% under deficit fertilization, regardless of the irrigation treatment. The half dose fertilized plants of 'Chili-AS Rot' had higher CS activity and PAL activity (from 50 to 80%) than fully fertilized plants, with deficit irrigation having about 10% higher enzymatic activity than field-capacity irrigated plants. In 'Naga Morich', irrigation treatment affected lower enzymatic activity than field-capacity irrigated plants.ConclusionsThe results indicate that deficit irrigation and fertilization can be used to maintain enzymatic activity and thus capsaicinoid content, which could reduce the economic cost of irrigation water and fertilizer. It was confirmed that the yield was better under deficit irrigation and fertilization for the more pungent 'Naga Morich'. The result of the study shows that when water and fertilizer use is reduced by up to 50%, chili yield losses are minimal or non-existent.Graphical

Water-physical properties of chestnut soils depending on different tillage practices and irrigation regimes

The aim of the research was to study water-physical properties of chestnut soils under different tillage practices when cultivating corn (Povolzhsky 89 MV hybrid) under irrigated conditions in the Lower Volga region. Therefore, the following characteristics of the soil were studied - soil density, soil moisture, field capacity, maximal hygroscopic moisture, wilting point and porosity. The results revealed that after chisel loosening, a qualitative improvement of soil water-physical properties was observed in comparison with the control variant - moldboard plowing. To describe the dynamics of changes in soil density by layers and tillage variants, a regression of the 2nd order was proposed, and coefficients of the equation were calculated. In order to maintain the specified irrigation regime during the observation periods, 7 to 9 vegetative irrigations with application rate from 2250 to 2750 m3ha-1 were carried out in the variants with moldboard plowing, 7 to 8 irrigations with application rate from 2200 to 2600 m3ha-1 in the variants with chisel loosening, and 6 to 7 irrigations with application rates from 2100 to 2500 m3ha-1 in the variants with chisel moldboard plowing. The yield of corn in the variant with chisel moldboard plowing averaged 8.75 tha-1 during the research period, which is 18 % higher than in the control variant. Moreover, the cost of irrigation water for producing one ton of grain decreased by almost 20 %, and the coefficient of water consumption decreased by 17 %.

Effect of nitrogen management on grain yield of rice grown in a high-yielding environment under flooded and non-flooded conditions

With increased cost and scarcity of irrigation water, flooded rice growing system may need to be replaced with water-saving technologies which includes part or complete removal of flooding and to be replaced with non-flooded aerobic conditions. However, to maintain high grain yield equivalent to that achieved with flooded rice, nitrogen (N) management may need to be modified. Experiments were conducted in a high-yielding environment with total N applied up to 180 ​kg ​ha−1 and three application times to determine its effect on N uptake, grain yield and grain protein content of rice grown under aerobic (AR), delayed permanent water (DPW) and flooded (FD) conditions. Grain yield increased by 3.50–4.50 ​t ha−1 with total N application rate of 180 ​kg ​ha−1 in AR and 120 ​kg ​ha−1 in both DPW and FD. Maximum yield was about 10.5, 12.0 and 13.0 ​t ​ha−1 in AR, DPW and FD, respectively, and the difference was mostly reflected in the grain yield difference obtained under 0 N application. Apparent recovery of fertilised N and agronomic N use efficiency were similar between AR and FD, but DPW took up a higher proportion of N fertiliser applied before commencement of flooding and had slightly higher grain yield response to total N application up to 120 ​kg ​ha−1. It is concluded that the limitation for grain yield for rice grown in the AR condition was the crop's inability to take up N from the soil, rather than the inability to take up N fertiliser or to convert the N uptake to grain yield.

The main aspects of the development of structural and technological devices made of modern domestic materials to ensure the safe operation of water intakes of reclamation systems

In the article, in order to solve various design problems of the hydraulic engineering and reclamation class, taking into account the conditions of functional operation of soft floating structures as water intake structures, the main aspects of the development of protective devices for irrigation water are formulated. As a result of the conducted research, based on the experience of designing water intake structures with water treatment systems, a specialized algorithm for solving problems of creating constructive and technological developments for reclamation water intakes in the water management complex was developed. The obtained results of the design and inventive tasks for a soft surfaced structure used as a water intake structure make it possible to select the estimated irrigation water costs (Q, m?/s) in the required quality and quantity and ensure the environmental safety of the reclamation system. In order to solve the tasks of ensuring the environmental safety of the reclamation system, the entire complex of structural structures, protective devices and technological equipment included in the water management complex was divided into three interconnected structural and technological schemes as part of a specialized type of natural-technical system “Water object – Water intake structures – Meliorative system”. Soft surfaced biopositive structures of a water intake structure as part of a reclamation system have been developed, in which the main protective agent is the first proposed by the author for the purification of irrigation water – a ruff filtrating load, which is an environmentally safe means of protecting the reclamation system from mechanical and biological contamination. An economic and mathematical model of a specialized type of natural-technical system “Water object – Water intake structures – Meliorative system”is presented, which represents the final stage of ensuring environmental safety of reclamation water intake, which is the main factor in increasing soil fertility and, accordingly, economic efficiency in the whole agricultural complex.

ОРОШЕНИЕ ТОМАТОВ ОТКРЫТОГО ГРУНТА: ОБЗОР РЕСУРСОСБЕРЕГАЮЩИХ ПОДХОДОВ

Purpose: to study and analyze resource-saving approaches to irrigation of tomatoes in open ground. Discussion. Tomatoes are one of the most commonly cultivated vegetable crops, as they have high nutritional, organoleptic and dietary properties, beneficial to human health. The problem of increasing tomato production can be solved by introducing scientifically based, experimentally tested cultivation technologies on reclaimed lands, one of the main elements of which is irrigation, which predetermined the relevance of research. Currently, sprinkling and drip irrigation, which have both advantages and disadvantages are used for irrigation of tomatoes. An analysis of features of tomato cultivation with different irrigation methods showed that their production in our country is cost-effective both with sprinkling and drip irrigation. However, the introduction of scientifically based drip irrigation regimes in tomato cultivation can increase significantly their productivity and the values of economic efficiency indicators with economical use of irrigation water. The most effective maintenance of pre-irrigation soil moisture on tomato crops is at the level of 80 % of the lowest moisture capacity. This drip irrigation rate of tomatoes in the open ground is considered optimal; with it the cost of irrigation water for the formation of a product unit is the smallest. Conclusions. The study of the differentiation of drip irrigation regimes of tomato by phases of growth and development of the crop showed that differentiated irrigation with drip irrigation systems in combination with the application of mineral and water-soluble fertilizers provide an increase in tomato yield in open ground, regardless of the region of their cultivation. A promising method for increasing the productivity of tomatoes and optimizing the cost of irrigation water during their cultivation are digital irrigation planning methods.

Modeling change in the ratio of water irrigation costs to farm incomes under various scenarios with integrated FADN and administrative data

The Water Framework Directive 2000/60/CE (WFD) of 2000 was issued by the European Union (EU) to prevent water deterioration and promote its restoration. It introduced a water pricing policy in the agricultural sector that is based on a ‘polluter-pays' principle.To date, some Member States have yet to comply with the pricing requirement for two main reasons: water cost estimates, as defined by the WFD, are particularly complex and difficult in the agricultural sector and farmers in marginal economic and environmental contexts may be unable to bear higher water costs.In Italy, water services are managed by regional administrations that also set irrigation water prices. This research estimated the effect of changes in irrigation water costs borne by farmers on farm incomes in a case study in the Aosta Valley Region where extensive farming is practice in a significantly naturallydisadvantage area. The analysis was modeled using four cost scenarios with economic data from the Farm Accountancy Data Network (FADN) integrated with irrigation water cost data provided by a regional administrative database. Estimated water costs averaged 2.65% and 1.06% of farm incomes, depending on the presence or absence of regional subsidies. Water costs represented higher income proportions on specialized grazing livestock farms, which is the predominant type of farming in Aosta Valley. These results raise concerns for WFD implementation, in particular, in mountain and agriculturallydisadvantaged areas with extensive and less-profitable farming.

Model of evapotranspirative subsurface irrigation tested with water lettuce

Providing irrigation for plants that is appropriate with the amount of the crop evapotranspiration or loss of water by plants is crucial to increase water productivity. One of the ways to increase irrigation efficiency is to apply a smart irrigation system. Intelligent automatic irrigation systems can be costly because they use a variety of microcontroller instruments. In this study, the irrigation model design utilizes automatic irrigation technology based on the evapotranspiration principle that can reduce the high cost. The objective of this study was to develop the evapotranspirative subsurface irrigation tested with water lettuce and test the performance of the model in terms of physical and economical water productivity. The evapotranspirative subsurface irrigation system used an inverted cone-shaped pots with an upper diameter of 40 cm. The pots consist of 1 pot as a supply of irrigation water, and 13 pots as planting pots. The pots are connected by a ½ in diameter pipe so that the water level at the pots is at the same level. The model yielded good results. The physical water productivity was 12.32 g liter−1 and economical water productivity of IDR 9.2/kg can save IDR 22.7/kg on irrigation water costs in crop production.

Quantitative Analysis of Eco-economic Benefits of Urban Reclaimed Water Greening Based on Emergy Theory

With an increased rate of urbanization and people’s interest in high-quality natural environments, urban green spaces are receiving increased attention. However, urban green spaces irrigation increases tap water consumption, wasting high-quality water. Using reclaimed water for irrigation can not only maintain the normal ecological and landscape functions of green spaces but also save water resources. The eco-economic benefits of using reclaimed water as irrigation water were evaluated in this paper. The composition of benefits was analysed, and a new quantitative method was proposed based on the emergy theory. This proposed method was used to calculate the costs of different irrigation water, the other use benefits of the saved tap water, and the benefits of scientific research, leisure and entertainment, carbon fixation and oxygen release, biodiversity protection, soil conservation and air purification. Taking Zhengzhou in 2018 as an example, the results showed that the cost of using reclaimed water to irrigate urban green spaces was 46% of the cost of using tap water. The total benefit of using reclaimed water to irrigate green spaces was $4.05 billion, which was three times the benefit of using tap water. The net benefit of using reclaimed water was $2.00 billion, while that of tap water was negative. Therefore, the advantages of using reclaimed water to irrigate urban green spaces are the low costs and high eco-economic benefits. The method proposed in this paper provides a quantitative basis for using reclaimed water to irrigate urban green spaces in cities with water shortages.

Simple hydro-economic tools for supporting small water supply agencies on sustainable irrigation water management

AbstractIn the Mediterranean countries, agriculture poses challenges in terms of its production expectations, resources availability, pollution, general management and implementation of economic tools (e.g. full cost of irrigation water, according to the Water Framework Directive). This study attempts to provide useful approaches for small water supply agencies facing multiple management, funding, environmental, and practical issues. A representative case in Central Greece is examined, in order to describe the situation in understandable terms supporting sustainable management. Simple hydro-economic tools were used to address these challenges; water balance, profits from agriculture, water value, water quality, management strategies, and full cost of irrigation water were simulated and incorporated into a decision support system (DSS), using Multi Criteria Analysis (MCA), involving experts on water resources management and local policymakers. This is the first hydro-economic study designed for a Greek rural agency, aiming to improve and encourage integrated monitoring and management at multiple levels, communicating more efficient water use approaches to local irrigation management communities.

Analysis of the Water–Energy Nexus of Treated Wastewater Reuse at a Municipal Scale

Treated wastewater has the potential to be a feasible alternative to supply non-potable uses and avoid water scarcity in urban areas, but it is important to understand and compare the associated energy consumption and CO2 emissions. This study presents a comparative analysis of the water–energy nexus associated with the traditional water supply and to the alternative reuse of treated wastewater, both for non-potable purposes. A case study of a Portuguese municipality was considered, regarding golf course irrigation and municipal gardens irrigation. A balance between production and demand was established, and the energy consumption and CO2 emissions were calculated considering the supply with drinking water and with treated wastewater. Three scenarios were defined to analyze the water–energy nexus for different configurations of the potential end-uses: (1) golf course supply, (2) municipal irrigation supply and (3) simultaneous supply to the golf course and to municipal irrigation. A quality analysis was also carried out by comparing the records from discharged wastewater quality parameters with the limits presented in the legislation for each proposed non-potable use. The results show that all scenarios present significant annual savings from using treated wastewater instead of drinking water from the public network, especially scenarios 1 and 3, that consider the golf course irrigation (water costs decrease by about 60,000.00 EUR/year). Regarding the water–energy nexus, this study reveals that treated wastewater spends less energy on its production and supply and produces fewer CO2 emissions. The energy savings can reach an average value of about kWh/year, with 5300 fewer kg of CO2 emitted in the best scenario.

Economic Analysis of Irrigation Water under Different Water Use Regimes in Godavari Command Area

A study was undertaken in Karimnagar and Warangal districts falling under the Godavari command area of Telangana to analyze the economics of irrigation among the farm households across surface water (SW), groundwater (GW) and conjunctive use (CU) regimes. Data was analyzed using descriptive statistics and natural resource economics tools. The farms under CU realized higher net returns per acre (` 11792) followed by GW farms (` 8229) and SW farms (` 7516). There was also an enhanced savings to the extent of ` 10900 per acre due to reduction in the expenditure on human labour, machine labour, marketing and irrigation cost under CU regime when compared to GW regime. The per annum volume of surface water used in the case of SW farms and CU farms was 263 acre inches and 182 acre inches, respectively. Volume of water used in case of CU is less when compared to SW regimes. Annual cost of irrigation water per acre was found to be highest in GW farms (` 6916) when compared to SW (` 1284) and CU (` 4063) farms. This study has shown the potential benefits of CU regime over SW and GW regime.

Applying a novel framework for the estimation of the full cost of water in a degraded rural watershed

Abstract Water Resources Management's modern concerns include solutions on water scarcity, water quality problems and the use of economic and decision-support tools. Especially, the agricultural sector in South Europe under the requirements of the Water Framework Directive 2000/60/EC(WFD) remains a challenge. Most scholars so far doubt and criticize the implementation of the full cost of irrigation water, review papers highlight the limited progress, and fewer cases provide guidance on how to address this case. The present study applies a novel methodological framework for the estimation of the full cost of irrigation water, based on hydro-economic concepts such as: water balance, profits from agriculture, water value, water quality, monetary, opportunity and environmental costs. Originally, the method has been applied only once in a rural watershed with surface and groundwater resources. Here, a degraded Greek watershed using only groundwater resources is the study area, and the results of the two cases are compared. The model was also examined under demand management strategies and recommendations to scrutinize the effects and the applicability of the proposed measures in hydrological and economic terms. The findings give useful insights on the future management of achieving economic objectives with environmental constraints and the harmonization of Greek agriculture to the WFD.

Efficient Irrigation of Maize Through Soil Moisture Monitoring and Modeling

Agriculture is the major user of water resources, accounting for 70% of global freshwater demand. As the demand for clean water increases, so does the need to implement more efficient strategies for water management in irrigated agriculture. While the benefits of precision irrigation in high-value crops, such as cannabis, tomatoes, and potatoes, are fully recognized, there is still need to investigate and implement cheap and efficient irrigation strategies for widespread low-value crops such as maize. In this study, the soil moisture dynamics in a sprinkler-irrigated maize field in Veneto (Northeastern Italy) was monitored using six time domain reflectometry (TDR) probes for the entire growing season. The TDR sensors were positioned at different depths into two separate sites: an Uninformed Site irrigated based on the farmer's experience and an Informed Site in which a water balance irrigation strategy was applied based on soil moisture measurements. A parsimonious hydrological model was then implemented and calibrated to quantify the different water balance terms (precipitation, evapotranspiration, lateral fluxes, and deep percolation). The comparison between the water budget terms in the two sites highlights that soil moisture monitoring during agriculture activities leads to substantial savings in terms of irrigation water volumes requirements and cost, without compromising the productivity of the crop field. A simplified upscaling of the results at the regional scale, assuming average conditions as in this study site and growing season, reveals that potentially significant economic savings, compared to the total profits linked to maize crops, could be possible.

Conservation agriculture enhances the rice-wheat system of the Eastern Gangetic Plains in some environments, but not in others

• Intensification of the rice-wheat system increased system productivity. • CA further enhanced the baseline system though CA benefits are environment-specific. • In fine-textured soil (silt-loam), CA enhanced system productivity and resource use efficiency. • In course-textured soil (sandy-loam), the system benefit (productivity and resource use efficiency) of full CA seems limited. Increasing productivity of the rice-wheat system (RW) in the Eastern Gangetic Plains (EGP) is a major challenge in the context of the various economic (increasing cost of labour, irrigation water, and energy) and bio-physical (water scarcity, depletion of soil fertility, and climatic variability) constraints. We evaluated the performance of three RW system intensification options with different management interventions over two years, comparing a conventional RW rotation (CS 1 ), with two stages of conservation agriculture (CA) interventions, (i) the simple inclusion of mungbean (CS 2 ), and (ii) the inclusion of mungbean together with full CA implementation (CS 3 ) at two sites in the EGP that differed with respect to soil type, water table dynamics, and agro-climatic conditions. Our evaluation focussed on improving system productivity and resource use efficiency. The addition of mungbean into the conventional RW rotation produced significantly higher system productivity (rice equivalent yield, REY) compared with the existing double-crop rotation across sites. The baseline system was enhanced further when CA-based management practices were adopted, however, the magnitude of system benefit from CA was site and situation-specific. At the fine-textured soil site, gains were observed in system production (by 5.4 %), irrigation water productivity (WP I , by 40 %), and N use efficiency (NUE, by 5%) for the CA-based intensified system (CS 3 ) in comparison with the CT-based intensified system (CS 2 ). The average wheat yield and WP I in the zero-till (ZT) system (CS 3 ) was always higher than in the conventional (CT) systems (CS 1 and CS 2 ), mainly due to enhanced wheat rooting after unpuddled rice across the sites. At the fine-textured soil site, the cessation of puddling in rice cropping maintained rice grain yield, while increasing WP I . However, in the coarse-textured soil site, the cessation of puddling resulted in lower rice grain production (by 14 %), coupled with much higher (1.3 times) irrigation water requirement than the conventional puddled rice systems (CS 1 and CS 2 ) in the second year due to increased percolation rate, which negatively impacted the overall performance of the CA-based system (CS 3 ). Therefore, the modification of the traditional CT-based system to an intensified CA-based approach can improve the productivity of the RW system in terms of yield of the component crops as well as better NUE and WP I in fine-textured soil, while the feasibility of the full CA system in coarse-textured soil seems limited due to poor performance of rice, and requires further research focusing on the best rice establishment option.

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.

Impact of climate change on economic components of Mediterranean olive orchards

Combining an olive growth simulation model with a specific module for economic components—namely, net margin (NM) and irrigation water productivity (IWP)—resulted in the AdaptaOlive v2.0 model. This model, used with perturbed climate (PC) and impact response surfaces (IRS), provided a tool that enabled the assessment of the impact of climate change on economic components of Mediterranean olive groves in southern Spain. Under future mild winter conditions, reductions in NM and IWP are expected; negative NM values may even be registered, with water availability having a relatively small effect on the results. In the opposite case, under future cool winter conditions, NM and IWP will increase, except for rainfed olive groves under low rainfall conditions, with water availability playing a major role. In addition, the distance (in terms of changes in temperature and rainfall compared to baseline conditions) to critical thresholds such as negative NM or IWP lower than irrigation water cost was assessed, identifying changes depending on weather conditions, water cost and olive oil price. Thus, future temperature increases of around 3 ºC under mild winter conditions could generate negative values of NM. These economic results impact the performance of adaptation strategies for olive groves, even ruling out some strategies that were previously recommended when only agronomic components were taken into account (e.g., deficit irrigation under mild winter conditions). There is thus a need for site-specific recommendations related to the use of irrigation and olive orchard management to maintain or increase the sustainability of these cropping systems. Despite the utility of using PC and IRS to achieve a scientifically sound evaluation of Mediterranean olive groves under future weather conditions, the approach presents some limitations that can be overcome using climate model outputs.