Irrigation and Drainage最新文献

Water stress and suboptimal nitrogen fertilization limit sustainable onion production. A two-season field experiment (2016–2018) evaluated the effects of varying irrigation (0.6, 0.9 and 1.2 ET_c as M₁, M₂ and M₃) and nitrogen levels (0%, 75%, 100% and 120% of recommended dose, RDN as N₀, N₁, N₂ and N₃) on evapotranspiration (ET_a), crop water productivity (CWP), irrigation water productivity (IWP), water-yield functions and yield response to water stress. Irrigation increased the ET_a (163–281 mm) and bulb yield (6.0–9.5 t ha⁻¹) while decreasing the CWP (3.01–4.12 kg m⁻³) and IWP (4.13–6.81 kg m⁻³). An optimum balance was found at an average ET_a of 220 mm, irrigation of 158 mm, yield of 8.2 t ha⁻¹ and CWP of 3.6 kg m⁻³. The overall yield response factor (K_y) was 0.78, indicating that onion is moderately sensitive to water stress, which improved with increasing nitrogen application. Among the treatments, microsprinkler irrigation at 0.9 ET_c with 120% RDN (M₂N₃) achieved the highest yield gain (65%), moderate CWP improvement (28%) and maximum net profit (109%) and benefit–cost ratio (107%) over the control (M₁N₁). These results suggest that M₂N₃ is the optimal strategy for water-scarce Indo-Gangetic plains and similar agroclimatic zones.

The frequency and intensity of drought are projected to increase globally, threatening plant growth. However, the role of elevated CO₂ (e[CO₂]) in plant drought recovery, particularly with respect to photosynthesis and water use efficiency (WUE), remains unclear. The study investigated the impact of e[CO₂] (800 μmol mol⁻¹) on the gas exchange parameters, stomatal morphology and distribution, and leaf tissue structure of tobacco plants under various water levels (full irrigation [FI], mild water deficit [MI], moderate water deficit [MO] and severe water deficit [SE]) within growth chambers. The results revealed that stomatal limitations significantly reduced CO₂ assimilation under MI to MO, whereas non-stomatal limitations became more prominent under more severe deficit. Moreover, the instantaneous water use efficiency (WUE_n) and intrinsic water use efficiency (WUE_i) of tobacco plants grown under e[CO₂] were approximately twofold greater than those of plants grown under ambient [CO₂] (a[CO₂]). Moreover, e[CO₂] led to distinct adjustment strategies in response to varying water availability, thereby alleviating the adverse effects of water deficit on plants. These findings indicate that e[CO₂] enhances leaf water use efficiency in tobacco plants by modulating stomatal behaviour and increase our understanding of the potential mechanism through which the CO₂ fertilization effect improves plant drought resistance.

China faces severe water scarcity, but the gradual implementation of irrigation management informatization (IMI), evolving from basic systems to AI-driven digital twin technologies, is helping alleviate this issue by improving water use efficiency. This study aims to enhance the understanding of IMI by documenting its development history since the country's founding, ensuring that future research can build upon past advancements. To achieve this goal, this study explores the evolution of IMI in China, from basic data collection to the integration of advanced technologies such as AI and digital twins, highlighting the parallel development of policies and technologies. It emphasizes the synergy between policy-driven technological advancement and technology-driven policy innovation, which has been crucial for optimizing IMI systems. Economic development has also played a key role in advancing these efforts, enabling investments in infrastructure and technology. The research further examines the role of stakeholder roles and interests in shaping policy implementation and technology adoption, providing insights into balancing competing priorities. The results provide valuable guidance for understanding the driving forces and development model of China's IMI system, strengthening water resource management, enhancing agricultural sustainability and ensuring sustainable development in a global context, particularly in achieving SDGs 2 and 6.

To study the influence of the end face inclination angle of an emitter on local head loss in a drip irrigation pipe, the end face of an in-line emitter was designed with various inclination angles; four levels—15°, 30°, 45°, and 90°—were set; and irrigation experiments and numerical simulations were carried out. Research indicates that the velocity and pressure gradient of the shrinking section and the expanding section of the drip irrigation pipe decrease with decreasing end face inclination angle of the emitter. Through the principles of dimensional harmony and multiple linear regression analysis, a model for calculating the local head loss of a drip irrigation pipe considering the inclination angle of the drip head is constructed. The local head loss is inversely proportional to 0.706 square of the cotangent value of the dip angle. Through the analysis of an example, when the distance between emitters is 0.6 m, the local head loss of a 60-m-long drip irrigation pipe with face inclination angles of 15°, 30°, and 45° is reduced to 26%, 45%, and 65%, respectively, compared with the 90° loss of the same specification. The research results can provide some reference for drip irrigation design and pipe network optimization.

This study focuses on the development of a smart vertical hydroponic system based on the Internet of Things (IoT). The system is programmed to regulate key aspects of hydroponic farming, including irrigation, growth environment and nutrient requirements. The experimental design evaluated the effects of nutrient solution flow rates (0.5, 1.0 and 1.5 lpm) and fertigation management systems (manual, commercial dozer and developed IoT-based dozer) for basil crops. During 2022–2023, growth parameters were monitored at regular intervals along with the yield and water consumption of each system. The results showed that the 1 lpm flow rate is the most suitable for the developed system. Compared with manual fertigation, the IoT-based fertigation system resulted in significant increases in plant height (12%), leaf area (16%), number of leaves (16%) and fresh weight (19%). These improvements helped the plants achieve significantly higher yields (19%) and water use efficiencies (18%). The IoT-based vertical nutrient film technique (NFT) hydroponic system continuously allows remote data monitoring and precisely manages fertigation automatically. Compared with traditional methods, the developed system achieved 5.46 times greater crop density. This study highlights the potential of integrating IoT and sensor technologies in hydroponic systems to improve nutrient management, crop productivity and sustainability in modern agriculture.

The objective of this study is to examine the causes of the decrease in river water quality along the path and to determine the locations where quality changes occur in the Meymeh Basin, west of Iran, so that, if possible, solutions can be provided to prevent the river from becoming salty. The hydrological model of the basin was developed via the semidistributed SWAT model to calculate the water budget and yield of the subbasins. Then, to check the salinity and salt balance of the subbasins and main river reaches, field data and salt load calculations are utilized. Model sensitivity analysis, calibration and validation were carried out via the SUFI-2 program. The results show that the average EC value of both periods at the origin of the Meymeh River (Kilometre 0) was 0.021 S/m. From the origin up to km 68, despite the addition of the Sarab-e-Gorab, Shahr-e-mir, Kharbozan and Vorazan tributaries to the main river, all of which have EC values higher than those of the main river, the rate of increase in the salinity of the river in both dry and wet periods occurred with a gentle slope, and at km 68, it reached an average value of 0.028 S/m.

Efficient irrigation management remains a critical global challenge, especially in regions experiencing water scarcity and the adverse effects of climate change. This study addresses these challenges by utilizing decision support systems (DSS) for the simulation and asset management of a pressurized drip irrigation network (PDIN) for avocado cultivation in Uganda, providing valuable insights that can be applied to comparable contexts worldwide. A systematic literature review (SLR) of articles on irrigation network simulation and sustainable management using GIS and RS was conducted. A geo-referenced hydraulic model and database were created using the QGISRed plug-in, reducing planning time and minimizing the need for time-consuming field surveys. The hydraulic analysis was based on the pressure-dependent demand (PDD) model. The CROPWAT 8.0 model was used to calculate the reference evapotranspiration (ET_o), resulting in a theoretical gross irrigation requirement (IW_Gro) of 5348.78 m³ ha⁻¹ year⁻¹. A cost analysis of irrigation water application yielded a value of US$2549 ha⁻¹ year⁻¹, while an economic analysis showed a net present worth (NPW) > 0.0 and a benefit–cost ratio (B/C) > 1.0. Thus, adopting DSS could reduce investment costs and achieve numerous Sustainable Development Goals (SDGs) including SDG2 (end hunger), SDG12 (responsible consumption) and SDG13 (climate action).

Improving water resource management is crucial for addressing irrigation water limitations and enhancing fertilizer use efficiency, thereby advancing sustainable agriculture. Negative pressure irrigation (NPI) is an innovative subsurface irrigation technology that has shown beneficial effects on agricultural production. However, the effects of negative pressure fertigation (NPF) on crop growth and the efficiency of water and fertilizer utilization have not been fully explored. Pot experiments were conducted to evaluate the effects of NPF on tobacco growth, water use efficiency (WUE), leaf potassium (K) content and nutrient uptake under three treatments: surface irrigation with surface K application (SIS), NPI with surface K application (NPS) and NPF. Compared with SIS, NPS and NPF reduced plant water consumption by 20%–24% and 12%–17%, respectively, while increasing WUE by 0.05%–23% and 7%–19%, respectively. In contrast to SIS and NPS, NPF did not negatively impact plant yield but improved leaf gas exchange parameters, such as increased photosynthetic rates, while slightly reducing stomatal conductance and transpiration rates, resulting in higher intrinsic and instantaneous WUE. Moreover, NPF increased the leaf K content and optimized the N:K ratio response, thereby improving tobacco quality. Overall, our results demonstrate that NPF could improve crop performance and resource use efficiency, highlighting its potential as a sustainable agricultural practice.

The aim of this study was to assess the impact of treated wastewater (TWW) and borehole water (BW) on certain properties of sandy soil during irrigation periods of 7, 45 and 100 days. Twenty-four soil monoliths were placed at the experimental palm grove of the University of Ouargla Algeria and irrigated with TWW or BW, with average electrical conductivity (EC) values of 5.82 dS/m and 2.57 dS/m, respectively. The soil pH, EC and sodium adsorption ratio (SAR) were determined before and after irrigation. The pH of the soil watered with TWW was significantly greater than that of the one irrigated with BW. Moreover, the type of water used as well as the irrigation period length significantly impacted the soil EC and SAR, which decreased drastically after 100 days of irrigation. Our findings provide relevant information on irrigation in arid and semi-arid regions, suggesting that TWW can be used as an alternative to BW to irrigate sandy soils.