Availability Of Irrigation Water Research Articles

Activity data on crop management define uncertainty of CH4 and N2O emission estimates from rice: A case study of Vietnam

AbstractBackgroundGlobally, rice systems are a major source of atmospheric CH4 and for major rice‐producing countries, such as Vietnam, CH4 as well as N2O emissions from agricultural land used for rice production may represent about one‐fourth of total national anthropogenic greenhouse gas (GHG) emissions. However, national‐scale estimates of GHG emissions from rice systems are uncertain with regard to its magnitude, spatial distribution, and seasonality.AimsHere, we used the biogeochemical model LandscapeDNDC to calculate emissions of CH4 and N2O from rice systems in Vietnam (Tier 3 IPCC approach). Our objectives were to identify hotspot regions of emissions and to assess the contribution of N2O to the total non‐CO2 (CH4+N2O) GHG balance of rice systems as well as the seasonal and interannual variability of fluxes in dependence of uncertain input data on field management .MethodsThe biogeochemical model LandscapeDNDC model was linked to publicly available information on climate, soils, and land management (fertilization, irrigation, crop rotation) for calculating a national inventory in daily time steps of CH4 and N2O emissions from rice systems at a spatial resolution of 0.083° × 0.083°. Uncertainty in management practices related to fertilization, use of harvest residues or irrigation water, and its effects on simulated CH4 and N2O fluxes was accounted for by Latin Hypercube Sampling of probability distribution functions.ResultsOur study shows that CH4 and N2O fluxes from rice systems in Vietnam are highly seasonal, with national CH4 and N2O emissions totaling to about 2600 Gg CH4 year–1 and 42 Gg N2O year–1, respectively. Highest emissions were simulated for double and triple rice cropping systems in the Mekong Delta region. Yield‐scaled emissions varied largely in a range of 300–3000 kg CO2‐eq Mg–1 year–1, with CH4 emissions during the rice season(s) dominating (>82%) the total annual non‐CO2 GHG balance of rice systems. In our study, uncertainty in field management information (nitrogen fertilization, ratio synthetic to organic fertilization, residue management, availability of irrigation water) were major drivers of uncertainty of the national CH4 and N2O emission inventory.ConclusionsOur study shows that Tier 3 approaches, that is, process‐oriented model approaches combined with GIS databases, for estimating national‐scale GHG emissions from rice systems are ready to be applied at national scale. Generally, this approach is powerful as it allows to identify regions with elevated emissions, thereby accounting not only for CH4, but as well for N2O emissions. However, our study also shows that specifically better information on land management is required to narrowing uncertainties.

Impact of climate change on future availability of water for irrigation and hydropower generation in the Omo-Gibe Basin of Ethiopia

Study regionOmo-Gibe River Basin, Ethiopia Study focusThe objective of this study was to predict the impact of climate change on the future availability of water for irrigation and hydropower production. Climate change projections for the near future (2017–2044), medium (2045–2072), and long-term (2073–2100) using a multi-model set average of fifteen regional climate models under the RCP4.5 and RCP8.5 emission scenarios. Water availability, allocation, and demand for irrigation and hydropower generation were predicted using the coupled Soil and Water Assessment Tool (SWAT) and Water Evaluation and Planning (WEAP) hydrological models. New hydrological insights for the regionThe projected annual average temperature increase range is 2.10–3.6 °C under RCP 4.5 emission scenarios while 2.7–4.8 °C under RCP 8.5. Under RCP 4.5 and RCP 8.5 emissions scenarios, projected annual average precipitation declines ranged from 10.7–13.6 % and 11.1–13.8 %, respectively. Projected annual average declines in streamflow ranged from 7.0 % to 10.9 % under PCR 4.5 emissions scenarios, while 10.9–2.8 % under PCR 8.5. As a consequence, water shortages for irrigation may decrease by 15.5–25.4 % and hydroelectricity by 10.5–20.2 % during study periods. Due to the combined effect of climate change and rising water demand, the increase in water scarcity ranges from 7.9–30.6 %. The projected results showed that future water availability for irrigation and hydropower generation will decline in the future. Climate change adaptation options are needed to ensure future water availability for hydropower generation and irrigation.

Meeting the Challenges Facing Wheat Production: The Strategic Research Agenda of the Global Wheat Initiative

Wheat occupies a special role in global food security since, in addition to providing 20% of our carbohydrates and protein, almost 25% of the global production is traded internationally. The importance of wheat for food security was recognised by the Chief Agricultural Scientists of the G20 group of countries when they endorsed the establishment of the Wheat Initiative in 2011. The Wheat Initiative was tasked with supporting the wheat research community by facilitating collaboration, information and resource sharing and helping to build the capacity to address challenges facing production in an increasingly variable environment. Many countries invest in wheat research. Innovations in wheat breeding and agronomy have delivered enormous gains over the past few decades, with the average global yield increasing from just over 1 tonne per hectare in the early 1960s to around 3.5 tonnes in the past decade. These gains are threatened by climate change, the rapidly rising financial and environmental costs of fertilizer, and pesticides, combined with declines in water availability for irrigation in many regions. The international wheat research community has worked to identify major opportunities to help ensure that global wheat production can meet demand. The outcomes of these discussions are presented in this paper.

Assessment of the Effect of Different Irrigation Regimes on Pod Yield, Water Requirement & Productivity and Economics of Groundnut Varieties under the Southern Telangana Zone, India

The research was conducted at the Regional Agricultural Research Station, Palem during yasangi (rabi) 2020-21 to assess the impact of irrigation regimes on yield, water productivity, and economics of groundnut varieties. The experiment was laid out in a split plot design and comprising of three irrigation levels viz., irrigation at IW/CPE ratios of 1.0 (I1), 0.8 (I2), and 0.6 (I3), as main treatments and four groundnut varieties viz., K-6, GJG-32, KDG-128 and K-9 as sub treatments and replicated thrice. The soil was sandy clay loam having PH 7.3, available N, P, and K of 195, 35.8, and 87.36 kg ha-1, respectively. The highest pod yield of 2278 kg ha-1 and lowest pod yield of 1842 kg ha-1 could be obtained at the IW/CPE of 1.0 and 0.6 respectively requiring 677.7 ha.mm/ha and 450.7 ha.mm/ha of irrigation water respectively. There was no significant difference in gross returns, net returns, and B: C ratios recorded with irrigation at 1.0 IW/CPE ratio (Rs 126989 ha-1, Rs 47607 ha-1, and 1.60, respectively) and 0.8 IW/CPE and significantly lower with 0.6 IW/CPE ratio (Rs.102673 ha-1, Rs. 28311 ha-1 and 1.38, respectively). It can be concluded that K-6 or K-9 varieties can be grown during yasangi (rabi) with IW/CPE ratio of 0.8 or IW/CPE ratio of 1.0 as per irrigation water availability for higher water productivity and net returns.

Pertinent Water-Saving Management Strategies for Sustainable Turfgrass in the Desert U.S. Southwest

Drought and heat stresses are major challenges for turfgrass management in the desert southwest of the United States where rainfall is insufficient to support managed turfgrass growth. Irrigation water availability and its quality are increasingly strained due to diminishing surface water supplies. Unprecedented drought conditions threaten the reliance on groundwater supplies that are heavily scrutinized for irrigation practices on landscape and recreational turfgrass. Therefore, development of drought tolerant cultivars, lower input turf management strategies that sustains turfgrass appearance and performance with less irrigation water, and tolerance to higher seasonal temperatures will be critically important. Sustainability of acceptable quality turfgrass can be accomplished through harnessing the natural genetic variation, genetic manipulation using modern genomic technology, and optimizing turfgrass management practices for improved drought tolerance. Besides persistent efforts of varietal development and improved turfgrass management for drought tolerance and performance, redefining the quality of irrigated turfgrass for consumers to align with the environmental conditions is envisioned to foster a sustainable golf, sports fields, and landscape turfgrass industry in the region. A comprehensive study encompassing different turfgrass species and enhancing management practices to achieve acceptable performing turfgrass as well as outreach education to improve public perception of realities for a “green” environment will be critically important. The recent developments in turfgrass science and contemporary communication platforms are instrumental in increasing awareness for a sustainable turfgrass paradigm and sustain eco-tourism of the region.

Yield Productivity and Nitrogen Uptake of Wheat Crop Are Highly Dependent on Irrigation Water Availability and Quality under Water-Limited Conditions

ABSTRACT The water scarcity can limit yield productivity of wheat, and this issue can be controlled using various management practices. The main objectives of this study were: 1) to investigate how N application rates and water quality affect the yield productivity, and plant growth characterization and nitrogen uptake of wheat crop under water-limited conditions; 2) to describe the relationships between nitrogen application rates and yields of wheat plants at low-quality water application times; 3) to predict the efficiencies of applied N fertilizers at different rates and water use efficiency. Field experiments on wheat crop were conducted for two consecutive growing seasons (2016–2017) at a private farm at Abis-Alexandria. The experimental design was split-plot design with three replicates. The main plot was nitrogen application rates (0, 75, 150, and 225 kg N ha−1) in the form of urea fertilizer (46% N). The sub-main plot was low-quality water application (LQW) (0%, 25%, 50%, and 75% from applied water requirements of wheat crop) co-applied with high-quality water (HQW). The obtained results indicated that the application of nitrogen fertilization with different rates significantly increased the economical and biological yields, grain/biological-nitrogen use efficiency, agronomic efficiency, nitrogen uptake, and water use efficiency for both grain and biological yields in the two seasons of cultivations. Moreover, the yield attributes such as spike length, number of plants and tillers were also significantly affected by N fertilization. Application of LQW at 25% and 50% co-applied with 75% and 50% HQW did not significantly decrease the yield and yield attributes of wheat in both seasons of cultivations. In contrast, the application of LQW at 75% co-applied with 25% HQW was significantly decreased the studied parameters. In conclusion, the best application ratio of LQW and HQW was 1:1 at 50% of LQW co-applied with 50% HQW at which the yield and its attributes of wheat did not significantly reduced.

Indonesia Rice Irrigation System: Time for Innovation

Indonesia is likely to face a water crisis due to mismanagement of water resources, inefficient water systems, and weak institutions and regulatory organizations. In 2020, most of the fresh water in Indonesia was used for irrigation (74%) to support the agricultural sector, which occupies 30% of the total land area in Indonesia. Of all agricultural commodities, rice is one of the major and essential commodities, as it is the basic staple food for almost every Indonesian. However, in 2018, the Ministry of Public Works and Housing (MoPWH) reported that 46% of Indonesian irrigation infrastructure is moderately to heavily damaged. Looking at how irrigation can be very crucial to the welfare of Indonesian population, this study conducted an extensive literature review of the historical, current, and future management of irrigated rice production systems in Indonesia. This study has clearly shown that the irrigation systems in Indonesia have existed for thousands of years and, thus, there is a close relationship between irrigation and the socio-cultural life of the Indonesian population. Aside from how climate change influences water availability for irrigation, rice production with a constant water ponding system has been found to contribute to climate change, as it emits methane (CH4) and other greenhouse gases from agricultural fields of Indonesia. Therefore, the required modernization of irrigation systems in Indonesia needs to consider several factors, such as food demands for the increasing population and the impact of irrigated agriculture on global warming. Multi-stakeholders, such as the government, farmers, water user associations (WUA), and local research institutions, need to work together on the modernization of irrigation systems in Indonesia to meet the increasing food demands of the growing population and to minimize the impacts of agriculture on climate change.

Infrastructure Performance and Irrigation Water Governance in Genadendal, Western Cape, South Africa

Disasters such as the 2015–2018 drought in South Africa usually negatively impact agricultural water, especially in smallholder farming systems. This study assessed the availability of irrigation water, performance of irrigation infrastructure, and water governance systems in Genadendal, Western Cape, with a focus on smallholder farmers. Data for streamflow, dam levels, and rainfall were acquired from water institutions and analysed using Microsoft Excel. The performance of the infrastructure and water governance were assessed based on the perceptions of smallholder farmers and key informants. A questionnaire was administered to eight smallholder farmers, followed by a focus group discussion with fifteen smallholder farmers. Interviews were conducted with eight key informants who worked in water-related institutions. Qualitative data from the interviews were analysed using thematic content analysis. The study showed adequate agricultural water resources during the 2015–2018 drought period for the smallholder farmers who relied on water from dams. However, smallholder farmers who relied on the Riviersonderend River experienced severe water shortages during the same period. The findings showed poor performance of irrigation water infrastructure due to inadequate maintenance. Lack of coordination among institutions, insufficient funding, political interference, fragmentation of roles and responsibilities, lack of human resources, and farmers’ lack of participation and commitment in water resource management all contributed to the dysfunctionality of irrigation water governance systems, leading to water insecurity. This study concludes that while agricultural water resources in Genadendal are sufficient, water governance systems need improvement in order to strengthen the water security status for smallholder farmers. This study recommends adequate funding for the operation and maintenance of infrastructure. Furthermore, water institutions need to support smallholder farmers with training skills in agricultural water management and infrastructure maintenance. Further studies are recommended to quantify the amount of water lost due to the poor performance of water infrastructure and to develop effective water governance in Genadendal. In addition, issues relating to crop varieties and changes in cropping intensity during drought periods need to be considered in future studies.

The Role of the Andalusian Institute for Agrarian Reform (IARA) in Irrigation Expansion: The Case of the Chanza Irrigation Project (Huelva, Spain)

In the last two decades of the 20th century, irrigation in Andalusia experienced a historic expansion as a result of the transfer of political powers from the State to regional authorities and, thanks to its application in Andalusia, to pass, among other measures, an agrarian reform bill and the subsequent development of new irrigation infrastructures. Against this background, our objective was to determine the role of the body responsible for implementing agrarian reform, i.e., the Institute for Agrarian Reform (Instituto Andaluz de Reforma Agraria, IARA), by converting drylands into irrigation lands, with a special focus on one of the region’s most vibrant agro-economically transformed areas: the irrigable area of the River Chanza (the west coast of the province of Huelva). To conduct the study, we have applied the historical method and content analysis to technical, legal and agro-statistical documentation from the entire active period of the IARA (1984–2011). The results highlight the leading role played by the IARA in extending irrigation land in agrarian-reform priority areas, as well as in developing irrigation infrastructures in the areas that the State defined as strategic in Andalusia, such as the 17,200 hectares of irrigated land of the Chanza Irrigation Project. We conclude that the radical agro-productive transformation of the coast of Huelva in recent decades is mainly due to the availability of water for irrigation, which the IARA was primarily responsible for planning and executing.

Modeling drivers of farming system trajectories in Mediterranean peri-urban regions: Two case studies in Avignon (France) and Pisa (Italy)

CONTEXTMediterranean peri-urban regions have changed considerably in recent decades, leading to different farming system trajectories. The high level of heterogeneity and complexity of these areas are particularly challenging in terms of understanding the ongoing processes and their drivers, including the effects of spatial interactions, in order to make an initial assessment of the possible levers for territorial management. OBJECTIVEWe aim to show a new modeling approach to assess the factors explaining farming system trajectories on Mediterranean peri-urban areas, including an analysis of the spillover from neighboring areas, which is often neglected in these kinds of methods. The model was tested in two urban regions, located in Pisa (Italy) and Avignon (France), leading to very different perspectives, given the differences in terms of farming systems and environmental characteristics. Our model also highlights the factors acting on peri-urban farming system trajectories. METHODSWe first analyzed the farming systems characteristics and their trajectories, based on a land parcel identification system database and agricultural census. Then, we estimated explanatory factors at the farm level applying a spatially explicit model which takes into spatial autocorrelations into account: a Spatial Autoregressive Probit model. RESULTS AND CONCLUSIONSOur results provide new evidence supporting the hypothesis that peri-urban farming systems trajectories are influenced by other variables than the distance to the city center and the urbanization processes. Although urban sprawl characterizes medium-sized regions, this factor is not relevant on farming systems trajectories in the region of Pisa, where structural agro-pedoclimatic drivers contribute more significantly to the probability of change and, therefore, highlighting the greater stability of these farming systems. The region of Avignon reveals different aspects: a dense road infrastructure and favorable environmental conditions (availability of irrigation water during warm periods, adequate temperatures in winter, deep soils) increase the probability of intensification within the farming system. SIGNIFICANCEOur methodological approach, which is based on a spatial probit model, measures the effect of the spatial dependence of the dependent variables. In addition, the preliminary classification in terms of farming systems improves our understanding of the land trajectories. The results obtained provide new insights into the processes underway in Mediterranean peri-urban areas.

Does Charco-Dam Technology Affect Production Efficiencies? Evidence from Small-Scale Vegetable Farmers in Nzega District, Tanzania

Abstract Water for irrigation is an essential and primary factor influencing crop productivity. However, there is limited information on how availability of irrigation water guarantees efficient use of inputs in farm production, especially for the rainwater harvesting technologies managed at household level. This study employed survey method to collect data from 528 small scale vegetable farmers, randomly selected from 5 wards and 5 villages, among the farmers 220 were adopters of Charco-Dam Technology (CDT) and 308 were non-adopters. Technical Efficiency Model was used to estimate production efficiencies of 528 small-scale vegetable producers, and Propensity Score Matching (PSM) Approach employed to evaluate the influence of adopting charco-dam technology on the production efficiencies of these farmers located in Nzega district, Tanzania. Results from the analysis present the essential intuitions about adoption of CDT and its effects on production efficiencies. It was observed that there was inefficient use of inputs (land-size, labour, quantity of improved seeds, amount of chemical used and amount of fertilizer used) among small-scale vegetable producers in the study area. The inefficiency was basically observed to be caused by household-size, cost of farm labour as well as growing cabbages and scarlet-eggplants. It is further observed that, farming experience, number of farm workers and radio listening behaviour reduced technical inefficiency (i.e., improve technical efficiency). Further analysis using PSM method, found that the adopters of charco-dam technology in the study area significantly increased the efficient use of inputs as compared to non-adopters, and hence realised high yields. This study recommends that, technologies like charco-dam should be encouraged, especially to small-scale farmers in arid and semi-arid areas. Furthermore, experienced farmers should share expertise on the use of inputs, with other less experienced farmers. In line with this, the role of agricultural information on improvement of production efficiency should not be undermined in improving efficient use of inputs. Hence, programmes and intervention that focus on encouraging farmers to listen to radio programmes related to agriculture, particularly those covering specific crop and location, are recommended.

Assessment of Agricultural Irrigation water from Groundwater in Lobalain District, Rote Ndao Regency, East Nusa Tenggara Province, Indonesia

Determination of water availability for irrigation consists of quantity and quality. However, water quality is generally often neglected. This study aims to determine the groundwater quality in order to meet the standard of agricultural irrigation quality standard in the Lobalain District, East Nusa Tenggara Province, Indonesia. The results showed that the groundwater quality with a predominantly pH value did not meet the standard. The none restriction on use class dominated the total dissolved solids (TDS) value. The average electrical conductivity (EC) value is less than 750 μs/cm. The chloride is dominated by less than the tolerance threshold (Cl-<4.0 meq/l), for sulfate (SO4), which is within the threshold (<20 meq/l), and the nitrate (NO3N) dominated as slight to moderate. The boron (B) showed positive results, which in all areas was very satisfactory because it is below the tolerance threshold (B<0.7 mg/l). The sodium percentage (Na%) analysis was dominated by excellent and good class, and the excellent category dominated the sodium adsorption ratio (SAR). Eight locations are highly recommended as agricultural irrigation sources due to their groundwater quality. Only one location is not recommended in Kuli Village because only three parameters (Na%, EC, and Cl-) meet the irrigation water quality standard.

Impact of Plant Growth-Promoting Rhizobacteria Inoculation on the Physiological Response and Productivity Traits of Field-Grown Tomatoes in Hungary

Drought-tolerant plant growth-promoting rhizobacteria (PGPR) may promote plant development under limited water supply conditions, when plant’s water demand is not completely satisfied under rain-fed conditions or when irrigation water availability is limited. The aim of this study was to examine the effects of two inoculation treatments (B2: Alcaligenes sp. 3573, Bacillus sp. BAR16, and Bacillus sp. PAR11 strains and B3: Pseudomonas sp. MUS04, Rhodococcus sp. BAR03, and Variovorax sp. BAR04 strains) and compare those to a control (B0) without artificial inoculation on chlorophyll fluorescence, leaf chlorophyll content (SPAD value), canopy temperature, and the yield of the processing tomato cultivar H-1015 F1 grown under field conditions. The young seedlings of the hybrid tomato variety H-1015 F1 were immersed in 1% of B2 or B3 products (BAY-BIO, Szeged Hungary) for 5 min. Inoculated and untreated seedlings were grown under three irrigation treatments [regular irrigation (RI), deficit irrigation (DI), and no irrigation (I0)], to reveal the effect of PGPR under different levels of water stress. In the dry year (2018), higher canopy temperature and chlorophyll fluorescence (Fv/Fm) were measured during flowering in plants treated with bacteria than in untreated plants. In the stage of flowering and fruit setting, the B3 treatment led to a significant decrease in the Fv/Fm value, canopy temperature remained high, and the SPAD value was statistically the same in all treatments. Under limited water supply, in most cases, PGPR led to a significantly greater total yield but more unripe green berries compared to untreated plants. Under moderate water shortage (dry year + deficit irrigation), the B3 treatment resulted in 26% more ripe, marketable fruit and 49% less unripe fruit compared to the B2 treatment. On the other hand, in the wet year (2020), the bacterial treatments generally did not affect physiological properties, though the B2 treatment produced a higher marketable yield while the amount of green and diseased fruits did not differ statistically, compared to the B3 treatment under deficit irrigation. Based on our study, we recommend the application of the B3 PGPR product as it positively affected key physiological processes, leading to a higher marketable yield particularly under water shortage.

A methodological framework for modeling sustainability visions: A case study of groundwater management in Faizpur distributary, Pakistan

Over the last two decades, participatory modeling has been advocated as an effective method towards integrated, adaptive, and collaborative water resources management. However, in developing countries, such as Pakistan, its adaptation is limited due to high cost, time, and technical skills of stakeholders. The proposed research aims to develop a stepwise participatory modeling framework with special focus to the problem of groundwater depletion in the Faizpur distributary of Bari Doab basin, Pakistan. Currently, due to absence of a well define groundwater management policy together with low social awareness level, groundwater sustainability is at risk in term of its quality and quantity. For participatory modeling individual causal loop diagrams were developed with potential stakeholders, followed by a merged causal loop diagram to represent a holistic view of the complete system. The final merged diagram helps in understanding different system processes and allows for a more comprehensive qualitative assessment of stakeholder proposed policies. Among other proposed policies (e.g., revise cropping pattern, gray water reuse, and construction of dams) water pricing is found to be the most effective policy. This policy proved to be helpful in improving irrigation efficiency and hence helps in reducing groundwater extraction. The policy may face resistance from upstream farmers due to excessive and cheap availability of irrigation water in their area, but can help in water reallocation and shift traditional methods of farming to more advanced techniques. The results point to social-economic aspects of groundwater management that have not been considered by other modeling studies to date. Moreover, this approach can improve the role of local stakeholder in decision-making processes concerning socio-environmental regulation and climate change mitigation policies.

Dietary changes could compensate for potential yield reductions upon global river flow protection

Non-technical summaryGlobally, freshwater systems are degrading due to excessive water withdrawals. We estimate that if rivers’ environmental flow requirements were protected, the associated decrease in irrigation water availability would reduce global yields by ~5%. As one option to increase food supply within limited water resources, we show that dietary changes toward less livestock products could compensate for this effect. If all currently grown edible feed was directly consumed by humans, we estimate that global food supply would even increase by 19%. We thus provide evidence that dietary changes are an important strategy to harmonize river flow protection with sustained food supply.Technical summaryTo protect global freshwater ecosystems and restore their integrity, freshwater withdrawals could be restricted to maintain rivers' environmental flow requirements (EFRs). However, without further measures, reduced irrigation water availability would decrease crop yields and put additional pressure on global food provision. By comparing the quantitative effects of both global EFR protection and dietary changes on regional and global food supply in a spatially explicit modeling framework, we show that dietary changes toward less livestock products could effectively contribute to solving this trade-off. Results indicate that protection of EFRs would almost halve current global irrigation water withdrawals and reduce global crop yields by 5%. Limiting animal protein share to 25, 12.5 and 0% of total protein supply and shifting released crop feed to direct human consumption could however increase global food supply by 4, 11 and 19%, respectively. The effects are geographically decoupled: water-scarce regions such as the Middle East, or South and Central Asia would be most affected by EFR protection, whereas dietary changes are most effective in North America and Europe. This underpins the disproportionally high responsibilities of countries with resource-intensive diets and the need for regionally adapted and diverse strategies to transform the global food system toward sustainability.Social media summaryCombining dietary changes and global river flow protection could contribute to a more sustainable food system.

Mulching improved soil fertility, plant growth and productivity, and postharvest deficit irrigation reduced water use in sweet cherry orchards in a semi-arid region

ABSTRACT In the Okanagan Valley, sweet cherry production has expanded to higher latitudes due to climate change, but the availability of irrigation water is limited in this semi-arid region. Postharvest deficit irrigation (PDI) and organic mulches can reduce water use in orchards, but their interactive effects on soil fertility, water relations, and crop performance in new orchard environments are unknown. In a randomized block split-plot design, full irrigation (100%) or PDI (72–76% of full irrigation) was applied to the main plots, and mulches (compost, woodchips, bare) were subplots at three sites. Compost increased soil organic matter, nutrients, pH, and electrical conductivity over three seasons at all sites. Woodchips increased tree growth and foliar P and Mn, while compost increased some fruit quality attributes, and foliar P compared to bare soil. Relative to full, PDI saved 24–28% irrigation water after harvest per season at each site without affecting soil moisture and chemical properties, stem water potential, or crop performance, or interacting with mulch effects. These results suggest that in this semi-arid cherry growing region mulches are a promising strategy to maintain soil moisture and improve soil fertility and crop performance, and PDI can reduce water use after harvest without affecting commercial production.

Rebound Effects in Irrigated Agriculture in Uzbekistan: A Stakeholder-Based Assessment

There is wide consensus among scholars and practitioners that improved irrigation technologies increase farm productivity and improve resource use efficiency. However, there is also growing empirical evidence that efficiency improvements in irrigation water use may create rebound effects, i.e., they may trigger changes in farmers’ behavior that partly or fully offset the technical water savings expected under ceteris paribus conditions. In extreme cases, total water consumption may even increase. We studied the impacts of introducing water-saving irrigation technologies in Uzbekistan and used structured stakeholder interviews for an expert-based assessment of potential rebound effects. Our findings contribute to the understanding of impacts of technological and institutional responses to environmental and economic pressures in sustaining water resources. The study demonstrates that although the objective of increasing irrigation efficiency may be achieved, the actual water savings under Uzbek conditions are likely to be reduced due to rebound effects. Unless there are effective policy interventions, we expect rebound effects through an increase in water supply for crops that compensates for current shortages of irrigation water availability, an increase in irrigated area, a switch to more water-intensive crops, and overall economic growth. The findings of this paper provide a reference point for estimating the water-saving potential and for evaluating and adapting policies.

ON- FIELD WATER MANAGEMENT OF GOLDA SMALL SCALE IRRIGATION SCHEME: THE CASE OF ASSOSA, NORTH-WEST OF ETHIOPIA

Miss management of available water for irrigation, both at system and farm level has led to a range of problems and further aggravated water availability and has reduced the benefits of irrigation investments. To solve irrigation water management problem; appropriate irrigation scheduling practices could lead to increased yields and greater profit for farmers, significant water savings, reduced environmental impacts of irrigation and improved sustainability of irrigated agriculture. This study was conducted for evaluating on-field water management of Golda small scale irrigation scheme which is found at Assosa, North- west of Ethiopia. In this study both secondary and primary data sources were used. Soil samples were collected for the determination of soil moisture, field capacity, and permanent wilting point, soil pH, organic matter content, total nitrogen and available phosphorous. Infiltration rate of the soil, crop water requirement, irrigation requirement and irrigation scheduling were determined. Application efficiency, storage efficiency and distribution uniformity of the system was evaluated. The organic matter content and available phosphorous of the soil were lowbut total nitrogen was high. Farmers were applying the same irrigation interval in each growth stage of the irrigated crop but crops are required different amount of water at different irrigation interval within each growth stage. The Application efficiency, storage efficiency and distribution uniformity were determined and the values were 51.6%, 91.6% and 80.76% respectively. Generally, irrigation users did not have sense of ownership for the scheme; poor irrigation water management was a problem as I have observed.

An economic analysis of impact of climate change in irrigation ecosystem of Tiruchirappalli district of Tamil Nadu, India

Climate change refers to long-term changes in the weather pattern and temperature trend. Due to drastic climate change and global warming, the availability of fresh water for irrigation became a major concern. Hence the present study was conducted to study the impact of climate change in canal, ground water and both canal and ground water irrigation ecosystems of Tiruchirappalli district of Tamil Nadu, India. For the present study, three blocks were purposively selected from the Tiruchirappalli district. 150 sample farmers were selected from 15 villages. Percentage analysis showed that there was an increase in irrigation intensity in all three-irrigation ecosystems and there was an increased number of irrigation for Sesame and Groundnut in the study area. All three irrigation ecosystems showed a decline in water availability. The irrigated area of major crops in the Tiruchirappalli district declined significantly along with an increase in the area of specific crops namely Sugarcane, Green Gram and Sorghum. The Ricardian model was employed to quantify the impact of climate change on the net income of farmers in all the three irrigation ecosystems. The Ricardian model revealed that both the Kharif season rainfall and the Rabi season rainfall had a positive impact on the net income of farmers in all three-irrigation ecosystems while the Kharif season maximum temperature had a detrimental effect on the net income in both canal and groundwater irrigation ecosystem. Tobit model was used to analyse the factors influencing the adoption of climate-smart technologies in the irrigation ecosystem. Tobit model results revealed that farm size, education and extension contact were the factors influencing the adoption of climate-smart technologies in all the three-irrigation ecosystems. The major constraint in all the three irrigation ecosystems was the labour shortage to adopt climate-smart technologies followed by the consequent yield reduction. Government should plan for climate strategies to enhance the beneficial effects and to mitigate the harmful effects of climate change in the district.

The impact of climate change on the availability of irrigation water at the rift valley lakes basin in Southern Ethiopia: A review

Agriculture is one of the foremost climate-responsive businesses, with open-air production systems sensitive to temperature and rainfall. This paper reviews recent literature and assesses the impact of climate change on the accessibility of water resources for irrigation. The paper critically reviews recent research findings on climate change's effect on the potential of surface water and groundwater for irrigation in Ethiopia's south rift valley (Abaya-Chamo) Sub-basin. Surface water in the south rift valley Ethiopia sub-basin, including the Abaya and Chamo lakes, is estimated to be just over 5,718 million m3yr-1. Finally, the implications for future study and development are emphasized. The effect of climate change (rainfall and temperature) on the water in the Abaya-Chamo lakes feeder Rivers is different for the near future (2021–2050) and extreme future (2071–2100) time using the RCP 8.5 scenario. Overall, findings show that the availability of water resources for irrigation purposes in the south rift valley Ethiopia sub-basin will be more vulnerable to changes in rainfall and temperature. In conclusion, Stream flow future projection (%) for each feeder river Bilate, Kulfo, Gidabo, and Hare are -9.07, -11.24, 3.89, 4.135, − 0.95, − 1.5, 13.4, and 15.4% respectively