Irrigation and Drainage最新文献

Undesirable changes in surface water and groundwater resources and land quality for biophysical and institutional reasons will further endanger the livelihoods of people in Central Asia. The farmers' understanding of these problems and the adaptation and solution strategies they opt for are the critical variables in devising relevant policies. Our findings captured significant disparities between farmer-perceived water shortages and officially documented water availability, as well as soil salinity discrepancies. Farmers' coping strategies, including crop alterations and water-saving measures, often lead to trade-offs, such as reduced crop yields. The study highlights the need to consider farmer perceptions and practices along with official data when designing policies. Effective policymaking must consider this dynamic interplay and the multifaceted challenges faced by farmers in these vulnerable Aral Sea regions.

Infiltration is one of the most important physical characteristics of soil and depends on various factors. This study investigated the influence of soil texture, layering and water head on the soil water infiltration rate. It also selected the most accurate infiltration models to determine the water infiltration rate in homogeneous and heterogeneous soil profiles. Experiments were carried out in four soil containers with a length, width and height of 20 × 20 × 70 cm. Treatments consisted of two soil textures (sandy loam, SL; clay loam, CL), four soil profiles (homogeneous texture, SL and CL; and heterogeneous texture, lighter texture on the top, SL/CL, and heavier texture on the top CL/SL) and three water head sizes (4, 7 and 10 cm). Several models were used to determine the water infiltration rate under homogeneous (Kostiakov, modified Kostiakov, Philip, Horton, traditional Green–Ampt, modified Green–Ampt and HYDRUS-1D) and heterogeneous soils (traditional Green–Ampt, modified Green–Ampt and HYDRUS-1D). According to the results, the infiltration rate decreased over time and along the soil profile. Nevertheless, it jumped at the interface of two-layered soils when the heavier soil was in the bottom layer (SC treatments) due to the high potential of the second layer, and then it decreased. In the reverse layering, the infiltration rate in the interface was lowest (CS treatments) because of the higher hydraulic conductivity of the second layer. Additionally, the infiltration rate increased with increasing water head, but the rate of this increase was higher by changing the water head from 7 to 10 cm. The results of infiltration models showed that the accuracy of these models was higher in clay loam texture than in sandy loam texture. The modified Green–Ampt was the most accurate model in homogeneous and layered soils, with average RMSE of 0.0204 and 0.019, respectively. The Horton model had the weakest simulation in homogeneous soils, with an average RMSE of 0.1299. Additionally, the accuracy of HYDRUS-1D in layered soils was less than that in homogeneous soils (NS of 0.95 and 0.85, respectively), and its accuracy decreased with increasing water head in most treatments.

In this study, the performance of a one-source surface energy balance (OSEB) remote sensing (RS) of actual crop evapotranspiration (ET_a), incorporating data from different spaceborne, airborne and proximal multispectral data, was evaluated. The RS platforms in this study included Landsat-8 (30 m pixel size), Sentinel-2 (10 m), Planet CubeSat (3 m), a handheld (proximal) multispectral radiometer (MSR) (1 m) and an unmanned aerial system (UAS) (0.03 m). A 2-year data set (2020 and 2021) from two maize research sites in Greeley and Fort Collins, Colorado, USA, provided ground-based data for estimating and evaluating hourly ET_a from the OSEB algorithm. The accuracy of OSEB hourly maize ET_a estimates was evaluated using calculated hourly maize ET_a using high-frequency data collected with an eddy covariance energy balance system installed at each research site. The results indicated that the Planet CubeSat multispectral sensor (3 m), combined with on-site surface temperature data, yielded the least errors when predicting maize ET_a. The hourly ET_a estimation errors for the Planet CubeSat were MBE ± RMSE of −0.02 (−3%) ± 0.07 (13%) mm h⁻¹. These results suggest the urgent need for a specific approach to improve RS multispectral and thermal radiometric data (quality) to better support sustainable irrigation water management practices.

Saturated hydraulic conductivity (K_s) plays a vital role in irrigation and drainage system design. Generally, K_s is estimated in the laboratory; however, it is expensive and tedious, especially in the Himalayan ranges where soil sampling is challenging due to topographical constraints. Therefore, in this study, pedotransfer functions were generated using multiple linear regression (MLR) models for the predictability of K_s in a Himalayan catchment in India. Fifty soil samples were collected and divided into two groups at a 70:30 ratio. Different soil attributes derived from 70% of samples were used for MLR generation, and attributes of the remaining 30% of samples were used for model validation. Six different MLR models constituting different independent soil attributes were generated and compared statistically. The results indicate that the MLR model comprising soil texture, bulk density, particle density, soil moisture content (MC), organic carbon content and porosity results in the highest adjusted coefficient of determination (R²; 0.93 and 0.89 during model generation and validation, respectively). Additionally, it was found that the weight basis MC ranged from 14% to 29% with a median value of 24%. These results demonstrate that simple MLR models can be used as an alternative to laborious experimental setups for K_s estimation. These findings can be used as guidelines for proper irrigation planning and design in mountainous catchments.

Future periods with limited water resources in Bangladesh will need the use of effective water-saving technology, such as mulching, to increase potato production in a sustainable way. This study investigated the effect of plastic mulch on soil hydrothermal status and its consequent effect on potato production over 2 years in field experiments in Bogura, Bangladesh. We cultivated potato under four treatments: two coloured (black and blue) plastic mulches, strip tillage and no mulch. The black plastic mulch raised the soil temperature by 1.2–2.4°C in the early growth stages and by 0.4–1.2°C in the later growth stages compared to the no-mulch treatment. This mulch raised soil moisture by 5.1–15.9% and reduced weed growth by 91% compared to no mulch. The nitrogen, phosphorus and potassium contents of the soil were significantly higher under the mulching treatments compared to no mulch. When compared to the blue and no-mulch treatments, black mulch provided 31–34% and 45–48% more tuber yield of potato, respectively, which significantly improved the economic benefits under mulching treatments. Black plastic mulch is therefore suggested as a workable adaptation approach to increase potato production under limited water resources in northern Bangladesh and elsewhere with similar agroclimatic conditions.

Assessing the efficiency gains, in terms of crop production and productivity, of using agricultural water management is critical to understanding the comparative advantage of using different storage and water-lifting technologies in irrigation development. This study aims to compare the efficiency differences among irrigation farmers using various water-lifting technologies and among users of various technology suites in the Central Rift Valley, Ethiopia. Cross-sectional data collected from 320 randomly selected smallholder farmers, considering the 2019/2020 production season, were used to analyse a one-step Cobb–Douglas stochastic frontier function. The results of the study revealed the existence of technical and allocative efficiency differences between gravity and fuel pump users. Factors that positively determine the level of technical efficiency scores are gender, age, education status, technology type and extension contact. Irrigation experience, access to credit, training and technology type positively affected allocative efficiency, while the distance to the irrigation water source had a negative effect. The findings have important implications for agricultural policy and practice as improving efficiency through the adoption of fuel-powered water-lifting technology could further improve overall agricultural productivity. Designing small-scale friendly business models and promoting irrigation extension services, among others, is critical for scaling successful water management technologies.

Utilizing unconventional water for sustainable agriculture is a multi-criteria process. Decision-making in such problems is based on finding the value of various criteria using advanced methods, for example the analytic network process (ANP). ANP is usually preferred in cases where the criteria are not independent and have intra-/intergroup relationships. Considering techno-economic and environmental criteria, the ANP structure was used in this study to investigate the feasibility of utilizing Chapaghli drainage water in western Golestan Province, Iran, for cultivating tolerant and semi-tolerant crops, including canola, barley, cotton and wheat, using GIS software. Irrigation water availability, techno-economic distance and land suitability for cultivation were selected as techno-economic criteria, while irrigation water quality, soil, plant sensitivity and aquifer vulnerability were selected as environmental criteria. The results show that canola is the best crop for cultivation with Chapaghli drainage water. This study provides a reliable decision-making infrastructure related to the recycling of drainage water for various cultivars in an area where environmental hazards are minimized.

Irrigation is one pillar of the Green Revolution that drove dramatic agricultural productivity gains across Asia. In Bangladesh, irrigation uptake has been so significant that 97% of dry-season rice is now irrigated. While most Bangladesh monsoon rice is completely rainfed, supplementary irrigation is sometimes employed where late monsoon onset is potentially yield-limiting. Station-controlled experiments provide a narrative of positive yield benefits from supplementary irrigation. In contrast, statistical evaluations of actual farm experience mostly show no yield benefit and lower profitability for supplementary irrigation adopters. To add evidence on this controversial practice, we evaluated data from 2012 and 2015 Bangladesh farm household surveys with causality econometric approaches that control for differences between supplementary irrigation adopter and non-adopter groups. After controlling for self-selection and endogeneity, we found no statistically significant yield benefit for supplementary irrigation. Our results support scepticism about the profitability of supplementary irrigation. As such, we recommend careful consideration of the mixed evidence on effectiveness in future supplementary irrigation project benefit cost analyses. Further evidence over a longer time and accounting for a broader range of crops is also important moving forward.

In the current study, mycoremediated textile effluents were used for irrigation in a cultivation system to promote resource recycling and cost-effective spinach production. The raw textile effluents from two different textile mills were decolorized by 93.2 and 94.5%, respectively, as well as mineralized by the immobilized novel fungus Geotrichum candidum. Subsequently, both the treated effluents, treated textile effluent 1 (TTE1) and treated textile effluent 2 (TTE2), were used to cultivate spinach. The results indicated that irrigation with TTE1 and TTE2 resulted in ~9% higher spinach yields compared with the control. Moreover, the water use efficiency with the TTE1 and TTE2 treatments was ~1.2 times better than that with the control. The need for fertilizers in the case of spinach cultivation with treated effluents was compensated by the textile effluents as a result of the breakdown and mineralization of the effluent by immobilized G. candidum. Notably, the energy content, dietary fiber and protein content of spinach irrigated with mycoremediated textile effluent were substantially elevated, with values of 34 kcal/100 g⁻¹, 3.4 g 100 g⁻¹ and 6.92 g 100 g⁻¹, respectively. The preliminary cost analysis indicated that the costs of the whole process (from treatment to irrigation) were approximately US$0.35-0.38 m⁻³ (INR 28.22–30.45 m⁻³) of textile effluent. The study concluded that the mycoremediated textile effluent could be efficiently applied for agronomic usages.

The CERES-Maize and AquaCrop models were evaluated for their performance in simulating maize (Zea mays L.) phenology, evapotranspiration (ETc), grain yield and crop water productivity (CWP). Model input data for calibration, validation and simulations were obtained from field experiments conducted from 2011 to 2014 that imposed three different irrigation levels (full irrigation treatment [FIT], limited irrigation treatment [75% FIT] and rainfed control) and five nitrogen (N) management treatments. Both models performed well in simulating the maize phenological stages, with simulated values being within 1–4 days of measured values for both models. Both models simulated grain yield well during the calibration with a normalized root mean squared error (RMSEn) of 5% (0.6 t ha⁻¹) for CERES-Maize and 8% (0.80 t ha⁻¹) for AquaCrop. The model error for ETc varied from −2 to +14% for CERES-Maize and ranged from −3 to ₊11% for AquaCrop. High N levels resulted in higher accuracy in predicting ETc. The AquaCrop model performed better than CERES-Maize in simulating irrigated crop production under different N levels under rainfed conditions. The performance of both models for rainfed systems was poorer than their performance in irrigated systems, indicating that both models need further improvements in simulating rainfed maize production systems.