Availability Of Irrigation Water Research Articles

The 2014 southeast Brazil austral summer drought: regional scale mechanisms and teleconnections

The southeast region of Brazil experienced in austral summer 2014 a major drought event leading to a number of impacts in water availability for human consumption, agricultural irrigation and hydropower production. This study aims to perform a diagnostic analysis of the observed climate conditions during this event, including an inspection of the occurred precipitation anomalies in the context of previous years, and an investigation of possible relationships with sea surface temperatures and atmospheric circulation patterns. The sea surface temperature analysis revealed that the southwestern South Atlantic Ocean region near the coast of southeast Brazil showed strong negative association with precipitation over southeast Brazil, indicating that increased sea temperatures in this ocean region are consistent with reduced precipitation as observed in summer 2014. The circulation analysis revealed prevailing anti-cyclonic anomalies at lower levels (850 hPa) with northerly anomalies to the west of southeast Brazil, channeling moisture from the Amazon towards Paraguay, northern Argentina and southern Brazil, and drier than normal air from the South Atlantic Ocean towards the southeast region of Brazil. This circulation pattern was found to be part of a large-scale teleconnection wave train linked with the subsidence branch of the Walker circulation in the tropical east Pacific, which in turn was generated by an anomalous tropical heat source in north/northeastern Australia. A regional Hadley circulation with an ascending branch to the south of the subsidence branch of the Walker circulation in the tropical east Pacific was identified as an important component connecting the tropical and extratropical circulation. The ascending branch of this Hadley circulation in the south Pacific coincided with an identified Rossby wave source region, which contributed to establishing the extratropical component of the large-scale wave train connecting the south Pacific and the Atlantic region surrounding southeast Brazil. This connection between the Pacific and the Atlantic was confirmed with Rossby ray tracing analyses. The local circulation response was associated to downward air motion (subsidence) over Southeast Brazil, contributing to the expressive negative precipitation anomalies observed during summer 2014, and leading to a major drought event in the historical context. The analysis of atmospheric and oceanic patterns of this event helped defining a schematic framework leading to the observed drought conditions in southeast Brazil, including the involved teleconnections, blocking high pressure, radiative and humidity transport effects.

Assessing the regional food insecurity in Bangladesh due to irrigation water shortage in the Teesta catchment area

Bangladesh is losing huge food production from the Teesta catchment area due to a lack of availability of irrigation water in the dry and lean period because of unilateral water withdrawal in the upstream country, India. The area, which is directly dependent on the irrigation water of the Teesta river, is the study area for this paper. The study reveals that rice production in Dalia, Nilphamari, Sayedpur and Rangpur regions is badly affected by the irrigation water scarcity. It appears that production is particularly severely affected in Rangpur, making it a relatively more food insecure area in the Teesta basin. The major finding of this study is that more than 4.45 million metric tons of rice production have been missed from the Teesta catchment area since 2006–07, triggered by the massive irrigation failure of the Teesta Barrage Irrigation Project (TBIP) due to reduced water flow in the Teesta river. The total rice production missed in the north-western region since 2006–07 is more than the country's total rice import during 2008/09–2013/14 fiscal years and nearly one quarter of the total boro production in the 2012/13 fiscal year. This reduced food production renders the north-western part of the country a food insecure region from its own production.

Desempenho produtivo e retorno econômico da cultura do sorgo submetida à irrigação deficitária

RESUMO A irrigação deficitária é comumente utilizada em regiões de reduzida disponibilidade de água ou de energia para a irrigação e visa incrementar a eficiência de uso da água. Essa técnica pode ser adequada à cultura do sorgo, que apresenta produtividades satisfatórias, mesmo em condições limitadas de disponibilidade de água no solo. Os objetivos do trabalho foram: avaliar os efeitos de diferentes manejos de irrigação deficitária sobre o índice de área foliar, altura de plantas e rendimento de grãos do sorgo, e identificar o nível crítico de irrigação deficitária que proporciona maior produtividade da água irrigada e retorno econômico. O experimento foi desenvolvido no ano agrícola de 2012/2013, sob uma cobertura móvel, que impedia a ocorrência de chuva na área experimental. Foram testados quatro manejos de irrigação deficitária: 100; 75; 50 e 25% de reposição da evapotranspiração da cultura (ETc). A redução de 25% na reposição da ETc resultou na diminuição de 7% na altura das plantas, 5% no índice de área foliar e 17% no rendimento de grãos. A maior receita líquida da cultura foi alcançada utilizando o manejo de irrigação com reposição de 75% da ETc. A produtividade da água e o retorno econômico da aplicação de água apresentaram uma resposta linear positiva em relação à redução na reposição da ETc.

Impact of Climate Change on Salinity and Drainage of Irrigated Lands in Mexico

About 10-40% of all irrigated lands in Mexico are affected by soil salinity at a high to moderate level, with 6 to 9% of irrigated lands having field drainage to control salinity. According to the existing climate change scenarios, a reduction of mean annual precipitation by 10 to 30% and a rise of mean annual air temperature by 2.3±1.0 °C are expected by the middle of the 21st century in the main irrigation regions in the center and northern parts of the country. These changes will reduce the availability of irrigation water by 30% compared to present levels. The objective of our study was to assess how the expected reduction in the availability of irrigation water could influence the salinity of irrigated lands and necessity for field drainage installation. Analysis of national data on the change of irrigated area affected by soil salinity during last years in Mexico and the experience of Aral Sea basin in the Central Asia with similar natural conditions and sufficiently detailed monitoring of the salinity of irrigated lands permitted to conclude that in case of less availability of irrigation water in Mexico the area affected by soil salinity will reach about 20 to 25% of irrigated lands, which means necessity not only to save irrigation water, but also further field drainage installation in large area.

STUDYING THE EFFECT OF SOME PARAMETERS ON QUINOA CROP

Agricultural irrigated area depends on the availability of irrigation water. To cope with scarcity of water supplies, deficit irrigation is an important tool to achieve the goal of reducing irrigation water use. Field experiments were carried out to study the effect of forward speed of seed drill (2.1, 3.6, 4.5 and 6.3 km/h), deficit irrigation (zero, 15 and 30%) and fertilization methods (broadcasting and fertigation) on the amount of water applied, productivity, water and fertilizer use efficiency, net return and net return/m3 of Quinoa (Chenopodium quinoa W.) in sandy soils. The main results of the study could be summarized as follow:- - Increasing the forward speed, increased field capacity and therefore, seed scattering was increased, vice versa field efficiency values were decreased. - Amount of water applied and water consumptive use were (1989 and 1611), (1750 and 1407) and (1527 and 1268) m3/fed for treatments zero, 15 and 30% deficit irrigation, respectively. The water saving was 12 and 23.2 % for treatments 15 and 30% deficit irrigation, respectively as compared with treatment zero deficit irrigation. - Seed and straw productivity, water and fertilizer use efficiency, net return and net return/m3 were increased under using fertigation method and forward speed of 3.6 km/h. - Net return/m3 under 15% deficit irrigation (2.55 LE/m3) was higher than under zero and 30% deficit irrigation (2.31 and 2.54 LE/m3) under fertigation method and 3.6 km/h forward speed. - Fertilization by fertigation was more efficiency than broadcasting fertilizers.

Blue Water Demand for Sustainable Intensification

The agricultural challenge of meeting global food demand requires an increase in the level of agricultural water productivity and some increases in global water use. But many arid or semiarid agricultural regions of the world are facing declining water availability for irrigation. Examples of declining groundwater availability are seen throughout arid and semiarid areas of North America, Africa, and Asia. Relevant to water demand for sustainable intensification of agriculture, this paper touches on concepts where policy can work toward improving water productivity, including: (i) assessing crop water use and productivity, (ii) promoting cultural practices for increasing crop water productivity, (iii) improving efficiency of green water use, and (iv) protecting agricultural water supplies. Developing a paradigm of assessing crop water productivity and comparing with potential water‐limited yields is a valuable diagnostic tool leading to improved management and water use. Similarly, water footprinting is a water accounting tool that should be applied toward improvements in agricultural water productivity. These assessment tools can prioritize how and when agronomic practices and plant genetic improvements can best be employed. This paper also overviews some cultural practices that can improve water productivity in dryland, rainfed, and irrigated systems. Several examples of policies that influence the supply of water for irrigation are given. Innovative policy structures are needed that allow sharing of water among agricultural, municipal, and environmental users while also rewarding conservation and efficient use. Specific policies that are designed to protect water supplies for agricultural use are needed.

Performance and impacts of managed aquifer recharge interventions for agricultural water security: A framework for evaluation

To minimize and counter decline of groundwater levels and improve the availability of water for crop production, Managed Aquifer Recharge (MAR) interventions are widely adopted across India, often initiated or supported by, local communities, state and central governments to improve the availability of water for irrigation. While the literature on MAR in India is vast, the science of their construction is lacking. Furthermore, there is an absence of a structured approach to evaluate the performance and impact of MAR interventions. Often, performance and impacts of MAR have been commented upon together, without distinguishing the two.In this article, we aim to propose that performance and impact are different from each other, and that the evaluation of MAR interventions should take into account such differences between them. A framework for performance and impact analysis, based on three levels, viz. primary, secondary and tertiary, is outlined. It is then applied to seven selected MAR interventions in India, Adarsha watershed – Andhra Pradesh, Gokulpura-Goverdhanpura watershed – Rajasthan, Kodangipalayam watershed – Tamil Nadu, Chikalgaon watershed – Maharashtra, Rajasamadhiyala watershed – Gujarat, Satlasana watershed – Gujarat and Sujalam Sufalam Yojana – Gujarat. Although, the evaluations of these case studies reported were not categorized into performance and impact, most of them have addressed both. However, none of them could explicitly demonstrate that reported impacts were uniquely related to MAR interventions. If impacts are used as a surrogate for performance, it must be shown that impacts are uniquely linked to MAR interventions.

Exploring the scope for transboundary collaboration in the Blue Nile river basin: downstream willingness to pay for upstream land use changes to improve irrigation water supply

AbstractIn this study we model the preferences and willingness to pay (WTP) of downstream farmers in one of the largest irrigation schemes worldwide in Sudan for improved irrigation water supply through transboundary collaboration with farmers upstream in Ethiopia. In a choice experiment, Sudanese farmers are asked to pay an increase in existing irrigation fees to secure future irrigation water availability by either enhancing the removal of sediments in their local irrigation channels or compensating farmers in the Ethiopian highlands for taking soil conservation measures to prevent land degradation and soil erosion. Although Sudanese farmers downstream do not feel very connected to farmers upstream in Ethiopia, we find a high degree of trust in international cooperation and a positive WTP for improved irrigation water supply and water use efficiency through transboundary collaboration.

La Baja California inventada: visiones sobre un territorio mexicano a mediados del siglo XX

This article examines the travels of Peter Gerhard and Ángel Bassols Batalla through the Baja California in the 1950s from a comparative perspective. From the theoretical viewpoints of the history of geography and the geographical journey as sources of information and working method in situ, the observation and empirical knowledge of the territory are established. The traveling style of both authors involves a cultural consideration, since an invented space emerges before their eyes from their own experience in the peninsula.As a traveler, Peter Gerhard journeyed the peninsula seeking the ancient missions that distinguished Baja California. That is why he organizad and integrated the information in a guide, in collaboration with Howard E. Gulick. He conceived the guide for tourists of the United States interested in this region so close to their country. Published in 1956, the guide became the most complete instrument for vacationists in general, and also for sport fishermen, hunters, explorers and campers. Although the guide was aimed for drivers, it also provided precise facts for people sailing in yachts or arriving in private planes. Due to their knowledge of the peninsular space, Gerhard and Gulick designed a series of maps by sections, and they proposed ten routes that could be followed, most of them by land, to arrive at any place through main roads, trails or paths, where travel was only possible by foot or mule. The routes, the historical and cultural aspects, as well as the practical recommendations for tourists given in the guide, prepared the way for what tourists would expect to look with their own eyes, and at the same time it facilitated mobility in a distant and isolated territory. In sum, as a traveler, Gerhard integrated a practical, pleasant and playful image for tourists of the United States that, with the speed and safety of the automobile could enjoy the sun, beaches, ranches, and embark in the adventure of the historical past at mission sites, in addition to hunting and sport-fishing.On the other hand, Bassols Batalla went deep into the territory as an explorer. He highlighted the value of his expeditions to Baja California by applying a geo-economic analysis methodology based in natural resources, he focused on productive activities (agriculture, cattle breeding, mining and hydraulic and sea undertakings), and became aware of the reality and problems of this region. For him, such perspective transformed the way of understanding the economic and social planning of Mexico. The relevant issue was the settling of the territory, the availability of water for irrigation, the study of soils and vegetation, the timber reserves in the forests, as well as the conservation and rational exploitation of fauna. Mining required more attention and a thorough examination of its reserves. Bassols Batalla expressed his opinions about the conservation of historical monuments, especially regarding the Jesuit and Dominican missions of the peninsula. Industrialization, and agriculture with its diversification in new cultivation areas, was a source of employment. For Bassols it was necessary to transform the roads and open a trans-peninsular highway to favor tourism and local development. In the eyes of this geographer, Baja California was the region of the future, but he concluded that first it was necessary to favor colonization, to consolidate the State and promote the national interest, as well as the reassertion of sovereignty.Finally, the comparison between the visions of Gerhard and Bassols show coincidences and differences that help comprehend the relevance of geographic travel as a source of information and as a working method, essential to understand the reality of an isolated region of Mexico. When Baja California was still isolated from the rest of the country, and at the same time its economic potential and its attractive landscape began to capture the public attention, the journeys of these authors, succeeded in inserting or adding the peninsula in the social imaginary of both the United States and Mexico.

English

Irrigation is a well established procedure on many farms and is practiced on various levels around the world. It allows diversification of crops, while increasing crop yields. However, typical irrigation systems consume a great amount of conventional energy through the use of electric motors and generators powered by fuel. Photovoltaic energy can find many applications in agriculture, providing electrical energy in various cases, particularly in areas without an electric grid. In this paper the description of reviews on a photovoltaic irrigation system, is presented. Photovoltaic water pumping system is one of the best alternative methods for irrigation. The variation of spatial and temporal distribution of available water for irrigation makes significant demand on water conservation techniques. Hence solar powered Automated Irrigation System provides a sustainable solution to enhance water use efficiency in the agricultural fields using renewable energy system removes workmanship that is needed for flooding irrigation. The use of this photo-irrigation system will be able to contribute to the socio-economic development. It is the proposed solution for the energy crisis for the Indian farmers. This system conserves electricity by reducing the usage of grid power and easy to implement and environment friendly solution for irrigating fields. Key words: Solar photovoltaics, water pumping system, irrigation, photovoltaic (PV) pumping system.

Challenges of Implementing Participatory Irrigation Management for Food Security in Semi-arid Areas of Tanzania

Participatory irrigation management (PIM) is theoretically assumed to reduce poverty significantly, but its practical experience and challenges are yet researched and documented in Tanzania. The study aimed at assessing challenges observed during implementation of PIM approach for food security in semi-arid areas of Tanzania. Data were collected through questionnaire, participatory rapid appraisal (PRA) tools, key informants interview, Focus Group Discussion (FGD), observation and literature review. Data collected from questionnaire were analyzed using SPSS. Data from other methods were analyzed using content analysis. The study revealed that PIM approach has contribution in improving food security at household level due to involvement of communities in water management activities and decision making, which enhanced availability of irrigation water and increased crop production. However, there were challenges observed during implementation of the approach, including the minimum participation of beneficiaries in decision making during planning and designing stages, which means that inadequate devolution of power among scheme owners, inadequate and lack of transparency on income expenditure in water utilization associations (WUAs), water conflict among WUAs members, conflict between farmers and livestock keepers and conflict between WUAs and village government leaders regarding training opportunities and status. The rules and regulation of WUAs were not legally recognized by the national courts and few farmers who planted trees around water sources. However, it was realized that some of the mentioned challenges were rectified by farmers themselves and facilitated by government officials. The study recommends that the identified challenges need to be rectified for farmers to realize more on the importance of PIM approach as it was realized in other Asian countries.

Modeling poplar growth as a short rotation woody crop for biofuels in the Pacific Northwest

Predicting the economic viability and environmental sustainability of a biofuels industry based on intensively cultivated short rotation woody crops (SRWC) requires spatial predictions of growth and yield under various environmental conditions and across large regions. The Physiological Principles in Predicting Growth (3PG) model was modified to evaluate the growth and yield of coppiced poplar (Populus spp). This included an additional biomass partitioning method and developing a sub-model which takes into account the impact of coppicing on post harvest regeneration, extending the applicability of the 3PG model to coppice management regimes.The parameterized model was applied to the entire Pacific Northwest of the United States, using appropriate climate and soil input data. Results predict the yield of poplar cultivation at a spatial resolution of ≈64 km2 throughout the ≈8,000,000 km2 of the study region. Existing agricultural cultivation patterns were used to estimate regional water availability for irrigation, and for non-irrigated regions, land cover features including ownership, slope, soil salinity and water table depth where used to select areas with a real potential to support a SRWC plantation.Results can be integrated with other models that allow for optimizing crop selection and biorefinery site selection. Important results include; an updated 3PG model for coppiced SRWC plantings, estimates of biomass feedstock yields under different irrigation patterns and weather conditions, and estimates for feedstock availability when combined with crop adoption scenarios.

Potential of Milk Thistle for Biomass Production in Semiarid Regions

ABSTRACTWater shortage is the major constraint for biomass production in semiarid regions. Biomass production of milk thistle [Silybum marianum (L.) Gaertn] and energy balance of this crop under different irrigation regimes (full and deficit irrigation) and soil organic amending treatments (poultry manure [PM] and vermicompost [VC]) was evaluated in a two‐year field experiment. Biomass yield reduced by 10 and 22% under moderate (I75) and severe deficit (I50) irrigation, respectively. Under deficit irrigation, the contribution of leaves and heads to the final biomass reduced in favor of the stalk. Regardless of the irrigation regime, application of soil amendments improved biomass yield. Total energy input used for milk thistle production was 9829 MJ ha−1, in which 68% was related to nonrenewable energy sources. Diesel fuel (51%) had the biggest share of energy used for milk thistle production, followed by irrigation water and machinery. Energy input in I75 and I50 was 7 and 15% less than full irrigation (I100). Net energy obtained from milk thistle was 116,688 MJ ha−1 with energy efficiency (energy output/energy input ratio) of 12.8. Taking into account that milk thistle is an annual crop with low energy input requirements, it seems that milk thistle has a considerable potential for biomass production using I75 in regions with limited irrigation water availability.

Deriving an index of adoption rate and assessing factors affecting adoption of an agroforestry-based farming system in Dhanusha District, Nepal

This paper attempts to fulfil the gap in measuring adoption in agroforestry studies. It explains the derivation of an index of adoption rate in a Nepalese context and examines the factors affecting adoption of agroforestry-based land management practice (AFLMP) in the Dhanusha District of Nepal. Data about the different farm practices and the factors (bio-physical, socio-economic) influencing adoption were collected during focus group discussion and from the randomly selected households using a household survey questionnaire, respectively. A multivariate regression model was used to determine the factors. The factors (variables) found to significantly affect adoption of AFLMP were: farm size, availability of irrigation water, education of household heads, agricultural labour force, frequency of visits by extension workers, expenditure on farm inputs purchase, household’s experience in agroforestry, and distance from home to government forest. The regression model explained about 75 % of variation in adoption decision. The model rejected ‘erosion hazard’, ‘flood hazard’ and ‘gender’ as determinants of adoption, which in case of single agroforestry practice were major variables and played positive role. Out of eight variables, farm size played the most powerful role in explaining the variation in adoption, followed by availability of irrigation water and education of household heads. The results of this study suggest that policies to promote the provision of irrigation water, extension services and motivation to obtaining higher education would probably provide the incentive to adopt agroforestry elsewhere in the terai of Nepal.

Causes of yield stagnation in irrigated lowland rice systems in the Senegal River Valley: Application of dichotomous decision tree analysis

In the Senegal River Valley (SRV), there was substantial yield gap between potential and actual yield obtained by farmers in irrigated rice production systems. Integrated crop management (ICM), covering almost all the agricultural practices from land preparation to harvest, was introduced to farmers for boosting yields since the early 2000s. A repeated farm survey was conducted over the period 2002–2010 to monitor farmers’ agricultural practices during the wet season in the Delta and Middle Valley of the SRV. The objectives of this study were to: (i) assess spatial and temporal variation in on-farm yields, and (ii) determine factors affecting variation in the yields through Classification and Regression Tree (CART) analysis. The data set consists of 829 farmer-year observations. While mean yields across nine years were 5.0 and 5.6t/ha in the Delta and Middle Valley, respectively, mean attainable yields (upper 10 percentile) were 7.2 and 8.6t/ha, respectively. Yield gap between attainable yield and mean yield was 2.2–3t/ha. There were no temporal trends in yield or yield gap in either zone. CART analysis identified six and eight yield determining factors. The primary factor was sowing time, and delayed sowing resulted in yield reduction by around 1t/ha in both zones. The major reasons behind delayed sowing were related to availability of credit, machinery, and irrigation water. The two other commonly identified factors were fertilizer management and bird control. We conclude that creating enabling environment through institutional arrangements for improving access to resources and machineries is essential for enhancing the adoption of ICM and breaking the yield stagnation. Development of alternative agricultural practices such as no tillage system is also needed to help farmers practice timely sowing.

Anaerobic membrane bioreactor for the treatment of synthetic wastewater to produce energy and water reusable in agricultural sector

Total utilizable water resource in India has been estimated to be about 1,123 billion cubic meters (BCM). Out of total water usage by different sectors, about 85% (688 BCM) of water usage is being diverted for irrigation, which may increase to 1,072 BCM by 2050. Since the demand for domestic and industrial water usage may increase in near future, the water availability for irrigation is expected to reduce. Overall analysis of water resources indicates that in coming years, there will be a twin edged problem to deal with reduced fresh water availability and increased wastewater generation due to increased population and industrialization. With increasing water demand and depleting water availability, recycling of domestic wastewater has huge potential in India to bridge the water scarcity and provide good source of water for non-potable use like irrigation. Considering various lacunas of conventional wastewater treatment technologies and cost implications of advanced technologies in Indian context, a need exists to develop sustainable technologies which can provide recyclable quality of water with low operating cost. An anaerobic bioreactor coupled with membrane unit is phrased as anaerobic membrane bioreactor (AnMBR) and could be an effective solution to treat low-strength domestic wastewater. The aim of this study was to evaluate the performance of external AnMBR for the treatment of sewage equivalent synthetic wastewater having 365 mg/l chemical oxygen demand (COD). Overall 95% COD removal efficiency was obtained during performance evaluation of AnMBR. The treated effluent with average COD concentration less than 20 mg/l was obtained for 8-h hydraulic retention time in bioreactor at 37 °C. The total suspended solids removal efficiency was 100% in AnMBR. The obtained biogas yield was higher than 0.4 m3/kg of COD removed in the system. The membrane flux was found higher than 60 l/m2 h at 1 bar trans-membrane pressure.

Agricultural Production under Climate Change: The Potential Impacts of Shifting Regional Water Balances in the United States

AbstractGeneral circulation models predict significant and accelerating changes in local patterns of precipitation and temperature during the twenty‐first century. Agriculture's vulnerability to climate change will depend on both the biophysical impacts of climate change on crop yields and on the agricultural system's ability to adapt to changing production conditions. Shifts in the extent and distribution of irrigated and dryland production are a potentially important adaptation response. Farmer flexibility to adapt may be limited, however, by changes in the availability of irrigation water under future climate conditions. This study uses a suite of models to explore the biophysical and economic impacts of climate change on U.S. fieldcrop production under several potential future climate projections, and to explore the potential limits and opportunities for adaptation arising from shifting regional water balances. The study findings suggest that, while irrigation shortages attributable to climate change have varying effects on cropland use, the aggregate impacts on national production are small relative to the direct biophysical impacts of climate change on yield.

EFFECT OF FERTILISER AND IRRIGATION ON FORAGE YIELD AND IRRIGATION WATER USE EFFICIENCY IN SEMI-ARID REGIONS OF PAKISTAN

SUMMARYIn many parts of Pakistan, availability of green forage is critical to livestock farmers. Forage production is often conducted with two succeeding crops grown within one year and it is highly affected by uncertain availability of irrigation water and low levels of applied mineral fertilisers. The objectives of the present study were to (i) evaluate the effects of crop species, fertiliser type and irrigation level on yield, (ii) determine the corresponding water use efficiency and (iii) investigate relationships between chlorophyll content and crop yield as a basis for a simple sensor-based prediction of crop yield for on-farm use. To this end a two-year field experiment was conducted in Faisalabad, Pakistan, with a completely randomised design with four replications in a split plot arrangement. A combination of fertiliser treatment (control, farm yard manure and mineral fertiliser) and irrigation (recommended irrigation, half recommended irrigation) were assigned to main plot whereas subplots were assigned to cropping systems (common (CCS): Egyptian clover (Trifolium alexandrinumL.) followed by corn (Zea maysL.), drought-adapted (DACS): Oat (Avena sativaL.) followed by Sudangrass (Andropogon sorghumsubsp.drummondii). Yield and irrigation water use efficiency of DACS was higher than CCS (14.8 and 26% respectively), the differences were bigger with reduced irrigation and fertilised crops used the available water better than the control. Positive linear relationships were found between chlorophyll concentration estimated by a chlorophyll meter and yield for all crops (r2= 0.63–0.96), suggesting this technique as a fairly accurate approach to predict yields of crops in vegetative growth stage.

WATER SCARCITY FROM CLIMATE CHANGE AND ADAPTATION RESPONSE IN AN INTERNATIONAL RIVER BASIN CONTEXT

We simulate and analyze the direct and indirect economic impacts of climate change on water availability for irrigation on the economy of the Netherlands and the other EU countries which share the Rhine and Meuse river basin (France, Germany and Belgium), employing a computable general equilibrium (CGE) model. We make use of the GTAP-W model, distinguishing between rainfed and irrigated land and irrigation water as input factors in agricultural production. We assess the scope of market adaptation to climate change by comparing the CGE results with the direct agricultural damage costs estimated using hydrological and crop growth models. We find considerable scope for market adaptation in that total economic impacts on agriculture are much lower when accounting for substitution effects and cross-sectoral and cross-country interlinkages, while the impact on the nonagricultural sectors becomes larger when these substitution effects and interlinkages are accounted for.

ANALISIS KETERSEDIAAN AIR PADA DAERAH IRIGASI BLANG KARAM KECAMATAN DARUSSALAM KABUPATEN ACEH BESAR

Blang Karam Irrigation with a total area of ± 400 Ha of rice fields have the potential to be developed which have supported such means Embung and Technical Irrigation Network. Availability of water for irrigation needs adequately met today with a reliable flow of 1.25 m3 / s and the need for retrieval of 2,312 liters / sec / ha on alternative cropping pattern with preparing land for 30 days and the need for making 0925 m3 / sec and 1,766 ltr / s / ha on alternative cropping pattern with preparing land for 45 days and the need for making 0707 m3 / sec. This suggests that the availability of water for Blang Karam irrigation area enough to meet the needs of the growing season irrigation water for 2 times a year.