Irrigation Costs Research Articles

The impact of poplar tree plantations for biomass production on the aquifer water budget and base flow in a Mediterranean basin

Poplar plantations are used for biomass production in many countries. These plantations are often located in areas where the tree roots can reach the water table of shallow aquifers to reduce irrigation costs and increase evapotranspiration, mainly during the summer. This study aims to assess the effects of these plantations on an aquifer water budget and on the stream flow of a Mediterranean basin (Santa Coloma River, 321.3km2 NE Spain). A numerical flow model was constructed to simulate shallow aquifers and to simulate the stream–aquifer interaction for a period of 9years. Once the model was calibrated, different land use scenarios, such as deciduous forests, dry farming and irrigated farming, were simulated for comparison. The mass balance shows that poplar extracts an average of 2.40hm3 from the aquifer, i.e., approximately 18% of the average recharge of the modelled area. This effect reduces the groundwater flow to the main stream and increases the infiltration from the stream to the aquifer. As a result, there is an average reduction in the main stream flow by 46% during the summer, when the lowest flow occurs and when the river is most sensitive. The results indicate that these impacts should be considered in basin management plans and in evaluating the benefits of this type of biomass production.

Drought, distress, and a conditional cash transfer programme to mitigate the impact of drought in Bihar, India

Paddy – Bihar’s staple crop – is vulnerable to drought, primarily due to the high cost of irrigation. In 2008, the Bihar government launched a conditional cash transfer scheme to subsidize diesel for irrigation in drought-affected areas. We show that this scheme has not been effective in mitigating the impact of drought on paddy production. A primary survey of potential and actual beneficiaries shows that low awareness and penetration among smallholders, alongside uncertainties and delays in the disbursal of the subsidy, make it ineffective. We suggest that in states with limited capacity, such ad hoc subsidies are unlikely to protect smallholders from weather shocks.

Groundwater modelling for need assessment of command scale conjunctive water use for addressing the exacerbating irrigation cost inequities in LBDC irrigation system, Punjab, Pakistan

Bari Doab on Pakistan side of the border, about 29,000 km 2 , is one of the most productive agri- cultural regions in the Sub-continent. The surge in population has increased the competition for available water resources. Ensuing to this, a number of irrigation- related issues have gained prominence. Effects of in- creasing climate aridity towards lower part of Bari Doab have emerged in the form of accelerated groundwater depletion. Lower Bari Doab Canal (LBDC) command, lying in the centre of Bari Doab, faces maximum spatial climate variability across its command area. This is the first model-based study of the long-term irrigation cost inequities due to successively increasing groundwater depletion towards the tail end. In the model, total water requirements of a grid cell are withdrawn from surface and/or sub-surface sources, based on rainfall and canal water availability. Groundwater pumping estimation is the most complex parameter; crop water deficit approach was adopted for the purpose. Due to excessive groundwater depletion, a tail-end farmer currently incurs 2.19 times higher irrigation costs as compared to the head-end counterpart. An additional depletion of 8-11 m is ex- pected in the lower half of the command till 2031, in contrary to stable conditions in head end. As a result this irrigation cost anomaly is simulated to be further aggra- vating to 2.36 times in year 2031. Thus, irrigation systems with significant spatial climate variability need appropri- ate command scale conjunctive management of surface and groundwater by the concerned irrigation planning and management agencies. This would help in plummeting the exacerbating irrigation inequities by reducing waterlog- ging and groundwater depletion.

Feeding and management techniques to favour summer sheep milk and cheese production in the Mediterranean environment

Sheep milk production in summer can lead to a diversification of milk products and to a more regular product distribution in the market throughout the year. However, in Mediterranean countries small ruminant production cycles are subjected to seasonal variations in forage resources. During summer, a key period for out of season production systems, nutrition plays a fundamental role in regulating the quantity and quality of milk production. In this review, feeding strategies and techniques that could be applied for out of season production in dairy ewes under different Mediterranean conditions are described for intensive, pasture-based and mixed systems. The most common feeding strategies used during the dry season are based on grazing post-harvest by-products or forage produced under irrigation. The criteria used to choose the appropriate forage species and to optimize the grazing technique are discussed here. In addition, types of forages and feeding techniques to be adopted for indoor systems, along with a series of feed supplements best suited to cope with heat stress, are described. The influence of feed resources and environmental conditions on milk and cheese production are also discussed. Overall, in order to be cost-effective, out of season sheep milk production systems must take into consideration the availability and price of feed resources, especially supplements, and irrigation costs. It is concluded that out of season milk production could be adopted primarily by farms with highly productive breeds, access to irrigated lands and appropriate management skills.

Impact of Lined Canal on Shallow Tubewell Irrigation and Their Acceptability by the Farmers

The comparative conveyance losses between lined and unlined canals, impact of water saving on command area development and irrigation cost, and farmers’ acceptability of lined canal in shallow tubewell (STW) irrigation schemes were studied during 2010-11 Boro season at three upazilas: Manikgonj Sadar of Manikgonj district, Dhamrai of Dhaka district and Mithapukur of Rangpur district. The conveyance loss was measured using inflow-outflow method and focus group discussion (FGD) was carried out with the pump owners and farmers to assess the impact of water saving on command area development and the acceptability of lined canal technology. Average conveyance losses were found to be 41, 48 and 45% in the existing earthen canals; 18, 21 and 24% in improved earthen canals; and 12, 11 and 13% in pre-cast canals at Mithapukur (M1), Manikgonj Sadar (M2) and Dhamrai (D) schemes, respectively. The water saving did not increase the command area in any of the schemes but reduced the irrigation time and saved fuel requirement for irrigation. On an average, 32, 23 and 30% fuel were saved by improved earthen canals where as 45, 46 and 48% were saved by pre-cast canals for M1, M2 and D schemes compared to earthen canal. The benefit-cost ratios of improved earthen canals were 1.36, 1.38 and 1.30 where as 3.36, 4.28 and 3.34 by pre-cast canals for M1, M2 and D schemes, respectively. The internal rate of return (IRR) from the investment on water distribution was over 50%. The lining technology was acceptable to pump owners, but did not impress the farmers who share the crop with the pump owners as price of irrigation or pay on the basis of irrigated area. In order to make the technology acceptable to the farmers, polices must be framed to share the benefits of lining by the pump owners with the farmers by reducing the price of irrigation water or through financial support of GO and NGOs for efficient use of STW irrigation system in Bangladesh.The Agriculturists 2014; 12(2) 116-125

Economics of Sugarcane Cultivation in Tirupattur Block of Vellore District

Sugarcane is one of the cash crop cultivated in many parts of the country with varying impact on the socio-economic condition of small and marginal farmers. Since sugarcane is cultivated across the country, Tamil Nadu is one of the important destinations where sugarcane is cultivated in an extensive manner and Vellore district prone to be a pioneer in sugarcane cultivation. The major varieties cultivated in Vellore district are coc82032, coc8201, coc90063, manjula cultivated across the district. The cost of inputs, soil conditions, irrigation & labour, which influence the production and productivity of sugarcane cultivation in the study area which are carried out under rainfed conditions. The study focused to study the different varieties of sugarcane cultivated in the study area, productive capacity of different varieties of sugarcane, resource use efficiency of inputs in cultivating sugarcane and to examine the intruding problems and suggest appropriate measures to enhance sugarcane production. The study was carried out in Tirupattur block of Vellore district, data was collected from 108 farmers on the basis of the land holding pattern. The data was collected during the month May and June 2014 from the selected farmers and analysed with the help of appropriate statistical tools. The findings of the study shows that the cost incurred on land preparation and cost incurred on pesticides are statistically significant at 5% level of significance whereas the cost incurred on Labour and area under sugarcane are statistically significant at 1% level of significance. It is also found that there exists high positive correlation between the total production and total income with respect to different varieties of sugarcane cultivation in the study area. The result from the chi-square test reveals that the different varieties of sugarcane namely coc86032, coc86021, coc90063 and manjula variety hutched marginal income to the selected farmers in the study area. The study suggests that necessary efforts should be made to safeguard the farmers against instability and take measures to improve the location-specific technology and to reduce the soaring cost of cultivation.

Grower demand for sensor-controlled irrigation

Water scarcity is likely to increase in the coming years, making improvements in irrigation efficiency increasingly important. An emerging technology that promises to increase irrigation efficiency substantially is a wireless irrigation sensor network that uploads sensor data into irrigation management software, creating an integrated system that allows real-time monitoring and control of moisture status that has been shown in experimental settings to reduce irrigation costs, lower plant loss rates, shorten production times, decrease pesticide application, and increase yield, quality, and profit. We use an original survey to investigate likely initial acceptance, ceiling adoption rates, and profitability of this new sensor network technology in the nursery and greenhouse industry. We find that adoption rates for a base system and demand for expansion components are decreasing in price, as expected. The price elasticity of the probability of adoption suggests that sensor networks are likely to diffuse at a rate somewhat greater than that of drip irrigation. Adoption rates for a base system and demand for expansion components are increasing in specialization in ornamental production: growers earning greater shares of revenue from greenhouse and nursery operations are willing to pay more for a base system and are willing to purchase larger numbers of expansion components at any given price. We estimate that growers who are willing to purchase a sensor network expect investment in this technology to generate significant profit, consistent with findings from experimental studies.

Surfactant Application on Yield and Irrigation Water Use Efficiency in Corn under Limited Irrigation

ABSTRACTDrought, and rising water and pumping costs dictate that continued production of corn (Zea mays L.) will be limited in future years if effective water conservation strategies are not established. This study was conducted to evaluate the effect of irrigation regimes in conjunction with surfactant treatments on field corn grain yield (GY), total dry matter (TDM) production, and irrigation water use efficiencies (IWUE) based on GY and TDM in a distinct Mediterranean climate, at Spadra Ranch in Pomona, CA, for 2 yr (2008 and 2009). The field experiment was set up in a split plot design with four replications where irrigation regimes (I40: 40%, I60: 60%, I80: 80%, and I100: 100% of the estimated evapotranspiration) was the main plot and application of surfactant (water treated with surfactant and no surfactant application) was assigned to the subplot. The results showed a stepwise reduction in TDM and GY in treatments both with and without surfactant as water deficit increased. However, surfactant application at any irrigation level resulted in higher GY and TDM compared to no‐surfactant treatments. Irrigation water use efficiency based on TDM and GY was the highest in I40 and the lowest in full irrigation (I100) conditions. By application of surfactant in irrigation water, both IWUE and GY increased. Surfactant application increased irrigation costs by 4.7%; however, it increased profit by 19.75%. Economic evaluation showed that the grain yield increment could compensate surfactant price and consequently the same profit achieved with applying 40% less water plus surfactant compared with 100% crop evapotranspiration with no surfactant application. In a Mediterranean climate and under limited irrigation conditions, corn could be cultivated with acceptable yields by application of surfactant.

Water Productivity, Irrigation Management and Systematization for Rice Farming Systems in Central Region of Uruguay

A high proportion of rice farming irrigation in the Central Region of Uruguay is done with water stored in dams. Maximizing water productivity is important as savings in water inputs would reduce pumping irrigation costs, increase rice area planted and allows to allocate water to irrigate other crops in a rotation. The aim of the experiment is to determine irrigation management practices and systematization field layout techniques that increase Water Productivity, contemplating the economic and environmental sustainability of rice farming systems in Uruguay. A split plot experimental design trial was conducted in the Experimental Unit located in Tacuarembo (32.11S, 55.10W). tThis paper includes results of the joint analysis of three seasons (2012-2013-2014). Treatments included two types of systematization with different vertical interval between levees (big plots): I. Conventional (VI-8 cm) and II. Alternative (VI-4 cm), and three irrigation management practices (small plots): 1.Continuous (C), 2.Intermittent until panicle initiation (IP), and 3.Intermittent during all crop cycle (I). In C a water layer of 10 cm is maintained after flooding throughout all the crop cycle. In IP and I the water layer is re-established when the soil is still saturated. Rainfall was above the historical average throughout the crop cycle, 738 mm. Crop was direct drilled on 10th October with 160 kg seed/ha with cultivar INIA Olimar (Indica). Basal fertilization was 160 kg ha-1 of 19-19-19 (NPK) and Urea was 100 kg ha-1 fractionated at tillering and panicle initiation. Intermittent irrigation (IP and I) in low-infiltration rate soils (planosols) allowed for significant water savings input (35% or 2798 m3 water ha-1) without reducing rice grain yield (average = 7713 kg rice ha-1) but affecting negatively industrial quality compared to Continuous irrigation (C) (P<0.05). Water productivity considering only irrigated water were: 0.99(c), 1.31(b), 2.00(a) kg grain m3 water-1 for C, IP and I respectively (P< 0.05). There was no significant effect of systematization in any of the parameters evaluated (P< 0.05).

Automação em sistema de irrigação tipo pivô central para economia de energia elétrica

A irrigação é de grande importância para a produção de alimentos, e acredita-se que ela seja responsável por boa parte da produção agrícola mundial, mas é grande consumidora de água doce, principalmente na irrigação por aspersão. O objetivo desta pesquisa é avaliar a redução do custo da energia elétrica para irrigação, por meio de sistema automatizado de controle de velocidade em pivô central instalado em encosta. Para tal, foi dimensionado um pivô central com raio de 56,4 metros com 10 emissores com pressão de serviço de 137,8 kPa, representando uma área irrigada de 1,3 ha, e a lâmina bruta de irrigação adotada foi de 10 mm dia-1. Posteriormente, realizaram-se cálculos para determinar as pressões em cada emissor, para as condições de 0; 10; 20 e 30% de declividade média do terreno. Posteriormente, foi montado um protótipo do pivô central em tamanho reduzido, com 6,3 metros de comprimento, com 10 emissores. Foi utilizado um conjunto motobomba de 2,21 kW (3cv), onde as perdas de cargas em cada emissor eram realizadas por meio de registros inseridos na linha lateral. A automação e o controle de velocidade implementada no protótipo possibilitaram a redução dos gastos em energia elétrica entre 18% e 52%. A automação desenvolvida mostrou-se viável e capaz de responder com agilidade a qualquer mudança de pressão.

The economics of irrigating wheat in a humid climate – A study in the East of England

In the UK, wheat is the most important cultivated cereal, grown extensively as a rainfed crop. Irrigation of wheat has previously been considered uneconomic, but increases in world wheat prices and recent droughts have led to some farmers revising their views. Widespread adoption of wheat irrigation would have major implications for wheat production, the irrigation industry and water resources in regions that are already water scarce. This study investigated the financial viability of irrigating winter wheat grown on a sandy loam soil in the East of England. Long-term climate data (1961–2011) for Silsoe (Bedfordshire) was used to drive a biophysical crop model to assess irrigation water requirements and yield response. Modelling assumed a typical irrigation schedule to maximise yield and quality, and average reported wheat prices for 2007 to 2012. Irrigation costs were calculated assuming an overhead mobile hosereel–raingun system applying river water, abstracted either in summer and used directly, or abstracted in winter and stored in an on-farm reservoir.The results suggest that the yield benefit would justify supplemental irrigation by farmers who have unused irrigation equipment and unused summer water, although irrigation of higher-value field vegetable crops later in the season would normally take precedence – the Added Value of Water (AVW) usefully applied to milling winter wheat under these conditions ranged between 0.24 and 0.32 £ m−3. Investment in new irrigation schemes could also be marginally viable if unused summer river water was available for direct abstraction (AVW = 0.08 £ m−3). Investments in new farm reservoirs for irrigating wheat are currently not profitable (AVW = –0.23 £ m−3). Sensitivity analysis suggests that in the longer term, the expected increase in world wheat prices and the impacts of climate change are likely to make the financial benefits stronger, particularly in the drier catchments further east and on low moisture retentive soils, but competing demands for water would still make extensive wheat irrigation unlikely.

Water and Fertilizer Productivity in Dry Season Irrigated Rice at Farmer’s Field

Two on-farm experiments were conducted during dry seasons, 2001-04 at Kurigram and Pirgonj in Thakurgaon districts to select the best water management practices and to find out the suitable and economically viable combination of irrigation scheduling and fertilizer dose for maximizing irrigated rice yield. In alternate irrigation at saturation (AIS) treatment, about 28% water was saved compared to continuous flooding (CF), but it was needed to apply water frequently. However, alternate wetting and drying (AWD) method saved 31% and 39% water in Kurigram and Pirgonj, respectively compared to CF. In both the sites, there was no significant yield difference among the water treatments, though the applied water varied from 836-1046 mm in Kurigram and 802-1092 mm in Pirgonj. The water productivity in Kurigram ranged from 0.62 to 0.89 kg m-3, whereas in Pirgonj it varied from 0.54 to 0.75 kg m-3. Besides, AWD had the highest water productivity irrespective of locations and farmer can follow AWD practices for achieving competitive rice yield with reduced irrigation cost. The soil test based (STB) fertilizer management gave the highest grain yield followed by BRRI recommend dose irrespective of water managements. About 33-35% less amount of water was required in AWD compared to farmer’s practice (FP) in both the sites having 0.5-1.0 t ha-1 yield advantage. In both the locations, the water productivity was the highest with STB fertilizer in combination with AWD water management which required additional fertilizer cost of Tk. 2800 ha-1, but resulted in added benefit of Tk. 8400 ha-1 compared to FP. In STB fertilizer treatment, nutrient uptake was more compared to BRRI recommendation and FP. It was concluded from the study that AWD water management practice was the best option for water saving and improving water productivity. The combination of AWD with STB fertilizer management is suitable for maximum return from rice cultivation in light textured soils.DOI: http://dx.doi.org/10.3329/brj.v17i1-2.20902Bangladesh Rice j. 2013, 17(1&amp;2): 64-74

Decomposition analysis of income difference between border strip irrigation and flood irrigation in cultivation of chickpea in Malaprabha command area of Karnataka

The present study was conducted in the Malaprabha command area as many scientific irrigation methods were implemented by the RKVY project. The required data were collected from the 35 farmers each practicing border strip method of irrigation (scientific) and flood methods of irrigation (traditional) in the cultivation of chickpea. The study revealed that the adopters of scientific irrigation technology produced 16.89 per cent higher income from border strip method of irrigation than flood irrigation. The increase in the income was further decomposed into different sources of change such as adoption of scientific irrigation technology and changed input levels. The scientific irrigation technology alone could contribute 9.37 per cent increase in income, while the contribution of change in input levels was also found to be positive (7.52 %). Amongst the various inputs, seed (-0.04 %), fertiliser (-1.01 %) and cost of irrigation (-3.67 %) contributed negatively whereas human labour (6.35%), bullock and machine labour (5.72 %) and FYM (0.17 %) contributed positively to the income.

An integrated crop and hydrologic modeling system to estimate hydrologic impacts of crop irrigation demands

The present paper discusses a coupled gridded crop modeling and hydrologic modeling system that can examine the benefits of irrigation and costs of irrigation and the coincident impact of the irrigation water withdrawals on surface water hydrology. The system is applied to the Southeastern U.S. The system tools to be discussed include a gridded version (GriDSSAT) of the crop modeling system DSSAT. The irrigation demand from GriDSSAT is coupled to a regional hydrologic model (WaSSI). GriDSSAT and WaSSI are coupled through the USDA NASS CropScape data to provide crop acreages in each watershed. The crop model provides the dynamic irrigation demand which is a function of the weather. The hydrologic model responds to the weather and includes all other anthropogenic competing uses of water. Examples of the system include an analysis of the hydrologic impact of future expansion of irrigation and the real-time impact of short-term drought.

Breakeven Cost of Irrigating Bermudagrass, Tall Fescue, and Orchardgrass Hay Production in Tennessee

Little is known about the economic feasibility of irrigating cool‐ and warm‐season grass species for hay production in the southeastern United States. The objective of this study was to determine the breakeven cost of irrigating bermudagrass [Cynodon dactylon (L.) Pers.], tall fescue [Schedonorus arundinaceus (Schreb.) Dumort., formerly Festuca arundinacea Schreb.], and orchardgrass (Dactylis glomerata L.) for hay production in Tennessee. Yield response to three irrigation levels during three harvest periods was estimated for the three grass species using data obtained from a 5‐yr study in a mixed model analysis. Partial budgets were developed to calculate annual net returns for irrigated and unirrigated hay production and to calculate the annual breakeven cost of irrigation for each grass. Orchardgrass and tall fescue hay yields negatively responded to irrigation during the spring harvest but positively responded for the summer and fall harvests. Similarly, bermudagrass hay yield positively responded to irrigation during the summer and fall harvests. For all three grass species, hay yield was greatest at the highest irrigation level (3.05 cm wk−1) during the fall harvest only. The breakeven costs of irrigation for hay production ranged between US$59 and US$87 ha−1 for orchardgrass, between US$66 and US$136 ha−1 for tall fescue, and between US$222 and US$335 ha−1 for bermudagrass. Results suggest that a producer would be more likely to increase net returns by irrigating bermudagrass than irrigating cool‐season grass species in the southeastern United States.

Decomposition analysis of income difference between furrow and border strip method of irrigation in cultivation of wheat in the Malaprabha Command Area of Karnataka

The present study was conducted in the Malaprabha Command Area as many scientific irrigation methods were implemented by the RKVY project. The required data were collected from the 35 farmers each practicing border strip method of irrigation (scientific) and furrow method of irrigation (traditional) in the cultivation of wheat. The data were analysed using the output decomposition model developed by Bisaliah (1977). The study revealed that the adopters of scientific irrigation technology produced 24.87 per cent higher income from border strip method of irrigation than furrow irrigation. The increase in the income was further decomposed into different sources of change such as adoption of scientific irrigation technology and changed input levels. The scientific irrigation technology alone could contribute 23.65 per cent increase in income, while the contribution of change in input levels was found to be positive (1.22 %). Amongst the various inputs, seed (-0.18 %), fertiliser (-0.53 %) and cost of irrigation (-2.34 %) contributed negatively where as human labour (1.41 %), bullock and machine labour (2.75 %) and FYM (0.11) contributed positively to the income.

An economic analysis of sweet sorghum cultivation for ethanol production in North China

AbstractSweet sorghum [Sorghum bicolor (L.) Moench] is a promising non‐food energy crop. The objective of this study was to determine the economic costs and input sensitivity of sweet sorghum compared to cotton, maize, and sunflower, at two saline‐alkali sites in Shandong (Wudi County) and Inner Mongolia (Wuyuan County) provinces of China. The data were collected quantitatively based on a face‐to‐face interview with 100 and 67 sweet sorghum growers at the two sites, respectively. The sweet sorghum grown at Wudi had lower external input (5469 CNY ha−1), higher net return (7305 CNY ha−1) and benefit‐cost ratio (2.36) than its reference crop, cotton (18 454 CNY ha−1; 3615 CNY ha−1; 1.24). At Wuyuan, the sweet sorghum showed contrasting economic performance (19 541 CNY ha−1; −3438 CNY ha−1; 0.91), which was largely because of the higher labor costs compared to sunflower (10 896 CNY ha−1; 15 133 CNY ha−1; 2.49); and maize (9108 CNY ha−1; 14 760 CNY ha−1; 2.76). The productivity of sweet sorghum per unit of external input costs (kg CNY−1) was 13.12 for Wudi and only 3.26 for Wuyuan. Based on the Cobb‐Douglas production function, the external inputs of diesel and seed had a significantly positive impact on the profitability of sweet sorghum at Wudi but not at Wuyuan. However, the costs of irrigation and film cover were significantly negative. The energy crop, sweet sorghum, showed a better return to scale on investment than cotton and sunflower.

Effect of different irrigation and tillage methods on yield and resource use efficiency of boro rice (Oryza sativa)

An experiment was carried out in Bangladesh Agricultural Research Institute (BARI) farm during 2010-11 to evaluate yield and resource use efficiency of transplanted boro rice under two tillage and three irrigation methods. Two tillage methods viz., conventional tillage with puddle transplanted rice and reduced tillage unpuddled transplanted rice and three irrigation methods viz., sprinkler irrigation, alternate wetting and drying (AWD) and flood irrigation were used as treatment variables. Grain yield was 7.62% higher in sprinkler and 4.72% higher in AWD irrigation method over flood irrigation method. Irrespective of tillage methods, reduced tillage method holds 4.62% higher yield production over conventional tillage method. Water use efficiency was found highest in sprinkler irrigation method (0.83 kg/m3) and in reduced tillage method (0.773 kg/m3). Labour required for land preparation was 15 md/ha in reduced tillage, whereas it was 38 md/ha in conventional tillage method. Seedling uprooting and transplanting required higher labour in reduced tillage method over conventional tillage. Fuel consumptions (49.78 l/ha) and electricity (3475.11 Kwhr/ha) was also less in reduced tillage method. Reduced tillage had less land preparation and fuel cost over conventional tillage method. But seedling uprooting and transplanting cost was higher in reduced tillage. Irrigation and total cost of production was 7753 Tk./ha and 69972 Tk./ha in Sprinkler × RT method. Benefit cost ratio was also higher in sprinkler irrigation (1.81) and reduced tillage method (1.82). DOI: http://dx.doi.org/10.3329/bjar.v39i1.20165 Bangladesh J. Agril. Res. 39(1): 151-163, March 2014

Reimagining cost recovery in Pakistan's irrigation system through willingness-to-pay estimates for irrigation water from a discrete choice experiment.

It is widely argued that farmers are unwilling to pay adequate fees for surface water irrigation to recover the costs associated with maintenance and improvement of delivery systems. In this paper, we use a discrete choice experiment to study farmer preferences for irrigation characteristics along two branch canals in Punjab Province in eastern Pakistan. We find that farmers are generally willing to pay well in excess of current surface water irrigation costs for increased surface water reliability and that the amount that farmers are willing to pay is an increasing function of their existing surface water supply as well as location along the main canal branch. This explicit translation of implicit willingness-to-pay (WTP) for water (via expenditure on groundwater pumping) to WTP for reliable surface water demonstrates the potential for greatly enhanced cost recovery in the Indus Basin Irrigation System via appropriate setting of water user fees, driven by the higher WTP of those currently receiving reliable supplies.

Seedling broadcasting as a potential method to reduce apple snail damage to rice

Exotic apple snails (Pomacea spp.) are a major threat to the productivity and profitability of rice farming globally. Cultural methods that are applicable to traditional rice transplanting are often successful in reducing snail damage to rice. However, high labor and irrigation costs associated with transplanting highlight the need to develop modern rice crop establishment methods to replace traditional, labor-intensive methods. This study examined four broad categories of rice crop establishment for their vulnerability to apple snail damage. Seedlings from dapog nurseries and wet-direct seeding were highly vulnerable to damage and produced no grain in snail-infested ponds in the Philippines. Rice transplanted from dry bed nurseries at 21 days after sowing (DAS) had high mortality (85%) and consequently low yields. In contrast, seedling broadcasting (21 DAS) significantly reduced rice vulnerability (22% seedling mortality) to snail damage compared to all other methods and resulted in the highest grain yields per plot in our experiments. We attribute lower vulnerability to snail damage and successful stand development to reduced transplanting shock at the time of seedling broadcasting and to the generally good condition of seedlings even after 21 days in polyvinyl chloride trays. We suggest that seedling broadcasting be considered as a crop establishment method with potential to sustainably manage apple snails in irrigated rice.