Irrigation and Drainage最新文献

Biochar application, as a kind of soil amendment, significantly influences soil physical and mechanical properties. This study revealed the effects of biochar application on the physical and mechanical properties of a clay-type soil at different irrigation levels. Soil was treated with three levels of biochar application: B0 (0 t ha⁻¹), B1 (25 t ha⁻¹) and B2 (50 t ha⁻¹), and three levels of irrigation: T0 (1.2 pan evaporation E_p), T1 (1.0 E_p) and T2 (0.8 E_p). The results indicated that other treatments reduced the soil bulk density compared with the control treatment (CK) (B0T1). Compared to CK, the highest reduction in soil bulk density was 18%. Irrigation did not improve the soil bulk density and porosity at the same biochar application in the short term. Biochar enhanced the stability of the soil aggregates. Compared to CK, the largest MWD (mean weight diameter) was enhanced by 9%. The addition of biochar and decreasing irrigation could decrease soil cohesion. The addition of biochar and increasing irrigation could increase the soil internal friction angle. The soil cohesion first increased and then decreased as the soil water content increased. According to the fitting formula, the soil cohesion was found to be minimum at B2T2, which was a decrease of 39% compared to B0T1. At the same irrigation level, the soil internal friction angle decreased with increasing soil water content. Soil penetration resistance showed a decreasing trend with the application of biochar. The more irrigation there is, the larger the soil penetration resistance.

This paper proposes a new methodology for investigating water management options in agricultural irrigation that accounts for the heterogeneity of irrigation system characteristics and limitations in existing water resources. The process uses a random data matching method to obtain operational management methods and system features using remote sensing data and water resource management optimization to evaluate different management methods. Regional modelling was performed, using the SWAP model under deterministic–stochastic conditions. Inputs such as sowing dates, irrigation procedures, soil characteristics, groundwater depth and water quality were treated as distributed data. To estimate these data, residual minimization was used between the field-scale evapotranspiration distributions modelled in the SWAP model and two Landsat 8 ETM+ images, as well as the Surface Energy Balance Algorithm for Land (SEBAL). The investigation of water management methods using distributed data as input was performed, and optimization of water management and data assimilation was achieved by applying the improved coyote algorithm. The case study was conducted in Mashhad during the dry season of 2018–2019. The results suggest that simultaneous consideration of crop and water management methods, rather than an independent evaluation, can lead to further improvement in regional wheat yield under water shortage conditions.

This study examined the existing cropping patterns, yield, irrigation water and energy use and carbon emission responses to explore the best cropping pattern based on the optimum water–energy–food and carbon emission nexus. The study consisted of field visits, questionnaire surveys among 510 farmers, 10 key informant interviews, one focused group discussion and subsequent analysis of collected data. The result of the research indicated that the best existing cropping pattern was rice–wheat–no crops with a net benefit of USD 491 ha⁻¹, benefit–cost ratio: 1.33, water use: 8830 m³ ha⁻¹, energy use: 43 GJ ha⁻¹ and carbon emission: 2420 kg CO₂-eq ha⁻¹. This study found spring rice to be the most appropriate agricultural commodity in the third season of the crop calendar and rice–wheat–spring rice, as the recommended cropping pattern in the selected area based on maximum production: 13.3 t ha⁻¹, the largest net income: USD 668 ha⁻¹, the highest benefit-cost ratio: 1.27 and the least use of energy 802 GJ ha⁻¹ with release of

3840 kg CO₂-eq ha⁻¹ of carbon. After applying the recommended cropping pattern of this study, there will be significant growth in the benefit per unit use of water and energy and a substantial reduction in carbon emission per tonne of food production.

This study numerically investigated the lining effect on the discharges and seepage losses of five reaches which belong to the El-Sont Canal, Asyut, Egypt, using FLOW-3D and Slide2 models, respectively. Two lining materials were considered, cement concrete (CC) and CC with low-density polyethylene (LDPE) film. A cost analysis was performed to explore the feasibility of the proposed lining materials. Moreover, a parametric study was conducted by the Slide2 model to investigate the effect of canal geometry and liner properties on seepage losses. An artificial neural network (ANN) model was developed based on the Slide2 model scenarios to estimate the seepage losses from lined irrigation canals. The results showed that reach the discharge calculated from the FLOW-3D model increased by 92%–97% and 149%–156%, while the calculated seepage losses from the Slide2 model decreased by 81%–87% and approximately 97% under CC and CC with LDPE film liners, respectively. Cost analysis revealed that the overall cost of CC with LDPE film was higher by 14% than CC. Relying on the importance of saving irrigation water and conveying water to the last reaches, CC with LDPE film is recommended for lining irrigation canals. A parametric study showed that the seepage losses were reduced by more than 96% when the ratio between liner and soil hydraulic conductivities was less than 0.01. A thick liner could maximally decrease the seepage losses by 68%, regardless of the canal geometry. As the developed ANN model showed a close agreement with the Slide2 results with coefficient of determination (R²) and mean squared error values of 0.99 and 0.05, respectively, the ANN model is recommended as a robust and rapid tool for estimating seepage losses from lined irrigation canals.

A 2-year field experiment was conducted on drip-irrigated olive oil orchards (Coratina var.) on a private farm in the newly reclaimed sandy soil of the West Nile Delta region, Egypt, during the 2020 and 2021 seasons to evaluate the effect of five irrigation treatments (120%, 100%, 80% and 60% reference crop evapotranspiration [ETo] and farmer practice) on applied irrigation water (AIW), water consumptive use, olive fruit and oil yields and some fruit quality parameters, water use efficiency, water productivity, electric energy consumed, farm income and benefit–cost ratio and to develop local crop coefficients (K_c) and yield response factors (K_y). The results indicated that the 2-year average AIW values were 9953 (17.9 m³/tree/year), 8484 (15.3 m³/tree/year), 6971 (12.5 m³/tree/year), 5480 (9.9 m³/tree/year) and 17,488 m³/ha (31.5 m³/tree/year) for the tested irrigation treatments. Olive fruit and oil yields and quality parameters were significantly affected by the tested treatments. The highest fruit and oil yields were recorded for the 120% ETo treatment. A seasonal K_c of 0.75 and a seasonal K_y of 0.83 were obtained. It can be concluded that producing oil from olive trees (Coratina var.) in sandy soils can be achieved by applying amounts of water equal to 80% or 60% ETo.

Soil salinity and sodicity problems are one of the major challenges to the permanence of irrigated agriculture in Ethiopia. This manuscript, therefore, concerns its spatial and temporal variation under irrigated fields and suggests possible management options. For this investigation, eight monitoring locations were selected based on the irrigation intensity that farmers practised in the area. With each location, three irrigated farmers' fields were randomly selected for sampling purposes. Likewise, six farmers' fields from the rain-fed system were also selected for comparison purposes. Sampling was performed at the beginning and end of each cropping season for three consecutive years from 2017 to 2019. The major physical and chemical properties of the soil were analysed in accordance with standard laboratory procedures. A linear model of two-way analysis of variance was used to analyse parameters across time and space. The results indicated that the majority of the soil properties studied showed significant differences (p < 0.05) over time. This implies that the change is in accordance with the seasonal soil property, possibly due to irrigation practices. Similarly, approximately 90% of the soil properties studied showed noticeable differences (p < 0.05) across locations. Almost all salinity indicators showed an increasing trend in irrigated fields compared to their situation in rain-fed fields. For instance, the electrical conductivity (EC) and exchangeable sodium percentage (ESP) values across the fields ranged from 0.54 to 0.82 dS m⁻¹ and 8–1%, respectively, with maximum values observed in irrigated fields. This implies that irrigation practices influence soil properties in the area. In addition, the ESP values approaching the maximum permissible limit suggest that sodicity may cause more problems than salinity in the area. Therefore, agronomic practices (e.g. residue management, deep tillage, salt-tolerant crops and periodic fallowing), irrigation and drainage management practices, and amendments may help farmers mitigate salinity and sodicity problems in the area.

To improve the hydraulic performance of leaf vein drip irrigation emitters, a combination of a genetic algorithm and numerical simulation was used to investigate the hydraulic characteristics of the model. The minimal flow index is used as the optimization objective to obtain the best design parameters for the flow channel structure. The results show that the leaf vein drip irrigation emitter has a flow index of 0.53, and the structural loss coefficient of the leaf vein drip irrigation emitter is 64.5–70.9 under 50 kPa working pressure, with a good energy dissipation effect. Among the design variables, the flow index (denoted as x) was influenced in the following order: the width of the unit structure f had the largest impact, followed by the vertical distance from the front baffle c, the inlet width a and the length of the unit structure h. The flow index x exhibited a positive correlation with the inlet width a, the vertical distance from the front baffle c and the length of the unit structure h, while it displayed a negative correlation with the width of the unit structure f. The correlation coefficient between the simulated and measured results was 0.994, with an average error of 2%, and the accuracy of the simulation results was high. Notably, the absence of noticeable low-velocity vortices at the corners and confluence of the leaf vein flow channel indicated excellent resistance to blockage.

In semi-arid Central Namibia, poor sandy soils limit sustainable crop production. We assessed cabbage performance in two split-plot field experiments. In Experiment 1, treatments comprised two irrigation levels: full irrigation (watered 3 days a week) and reduced irrigation (watered 2 days a week) as the main plot factor and six soil amendments (biochar; compost; zeolite; nitrogen, phosphorus potassium [NPK]; Be-Grow boost [L] hydrogel; and hoof and horn + bone [HHB] meal) as subplot factors in three replications. Full irrigation produced a significantly higher yield (21.1 t ha⁻¹), head weight (0.958 kg) and larger head girths (42.1 cm). Biochar produced the highest marketable heads (24,884 heads ha⁻¹), water use efficiency (76.0 kg ha⁻¹ mm⁻¹) and the largest head girths (42.7 cm). In Experiment 2, water was applied 5 and 4 days a week for full and reduced irrigation; the application rates of compost, HHB meal, Be-Grow boost (L) hydrogel and NPK were modified. The interaction of Be-Grow boost (L) hydrogel, NPK and biochar with full irrigation and HHB meal with reduced irrigation produced more marketable heads (28,935, 28,009, 27,546 and 28,703 heads ha⁻¹, respectively). Therefore, full irrigation with these amendments could be used for resilient cabbage production in Central Namibia.

Deficit irrigation (DI) could be an important strategy to achieve the goal of reducing irrigation water consumption. This review aims to identify the impact of different DI strategies on grain yield, water use efficiency (WUE) and oil and protein content in soybean seeds. A total of 25 articles were considered and then divided into DI throughout the whole cycle (standard deficit irrigation, StDI) and DI only at certain stages of the cycle (regulated deficit irrigation, RDI). In StDI, yield reductions were approximately 20% when the replacement of the crop water requirement was between 70% and 90%. For RDI, yield reductions ranging from 9% to 30% were observed depending on the phenological stage at which the crop evapotranspiration (ET_c) deficit was imposed. StDI always increased WUE compared to full irrigation, whereas for RDI, the response in terms of WUE changed considering the stressed phenological stage. Few studies have reported the effects on oil and protein content, showing high variability and contrasting results. In general, the application of a reduced amount of water led to a decrease in yield and an increase in WUE, with a magnitude significantly influenced by the stage at which the stress was imposed.