Search Results (43)

This study analyzed the distribution of water and nitrogen in the vertical pipe surface drip irrigation system under the condition of sandy loam soil, and established a prediction model for the wetting front transport distance. A constant-head infiltration test established a critical stable infiltration model, matching dripper flow rate (Q) with pipe diameter (D), pipe burial depth (B), and biogas slurry concentration (C). Indoor soil box experiments with Q, C, B, and D were conducted. Results show that a stable infiltration rate has a power function relationship with C, B, and D (R² = 0.96). Wetting front transport distances in three directions are proportional to Q and inversely proportional to C, B, and D. The empirical model is reliable (RMSE < 1.18 cm, NSE > 0.95). Soil moisture and total nitrogen accumulate near drippers. Q and C significantly affect wetting front transport distance. Water plays a limited role in nitrogen transport within the soil profile. The model accurately predicts wetting front distance, filling knowledge gaps, and providing theoretical support for system optimization. Full article

Utilising highly mineralised mine water for drip irrigation of desert vegetation in mining areas represents a crucial approach to alleviating freshwater scarcity and achieving mine water resource utilisation. However, high salt inputs may pose risks of salt return to root zones and deep accumulation. To ensure the safe and effective utilisation of mine water, laboratory 45 cm soil column infiltration tests (freshwater, 8, 12, 16 g L⁻¹) were conducted in the heavily saline-affected desert vegetation zone of Dananhu, Hami, Xinjiang, alongside 2023–2024 field drip irrigation trials (8, 12, 16 g L⁻¹). This study established a ‘soil column inversion–field validation–scenario optimisation’ framework (16 g L⁻¹) and field drip irrigation trials (8, 12, 16 g L⁻¹) during 2023–2024. A multi-scale HYDRUS-1D/3D simulation framework—‘soil column inversion–field validation–scenario optimisation’—was established to quantify water–salt transport processes in the root zone and optimise emitter flow rates. HYDRUS-1D demonstrated excellent fitting for soil moisture content, wetting front, and salinity distribution (R² = 0.964–0.979, 0.995–0.998, 0.791–0.898). Following parameter migration, HYDRUS-3D achieved R² values of 0.834–0.949 for simulating field-scale stratified salinity. Overall desalination occurred in the 0–80 cm soil profile over two years. Within the 0–40 cm root zone, reduction rates decreased with increasing irrigation salinity: 45.77% (2023) and 59.64% (2024) under 8 g L⁻¹ treatment, significantly higher than the 24.24% and 30.91% reductions observed at 16 g/L (p < 0.05). During the high-temperature period of July–August, transient salt accumulation occurred in the 0–10 cm surface layer, while the 80–120 cm zone exhibited cumulative risk. Scenario simulations indicated that increased dripper flow rates expanded the wetted zone horizontally but weakened vertical leaching. The 2.0–2.4 L h⁻¹ range demonstrated superior overall performance in balancing root zone desalination rates and irrigation uniformity. The study recommends targeting root-zone salinity stability through a combination of moderate leaching, summer transpiration suppression, and seasonal flushing/natural leaching, alongside prioritising low-to-medium flow emitters. This approach synergistically reduces both surface salinity return and deep accumulation risks. Full article

Clogging is a major constraint to the agricultural reuse of produced water; however, ultra-low-frequency dynamic electronic pulses (EPs) can help control biofouling in drip emitters. This study aimed to evaluate the reduction in clogging in non-self-compensating emitters applying onshore oil-and-gas-produced water treated with EP. Three experimental benches were assembled using drip irrigation units supplied with different water sources: water supply (WS), produced water with EP (OPW + EP), and produced water without treatment (OPW). Hydraulic performance was monitored every 40 h for 400 h using average flow rate variation (AFVR), flow variation coefficient (FVC), and distribution uniformity (UD) indices. Data were analyzed using RT-1 analysis with Bonferroni post hoc tests. Results showed that the interaction between water sources and evaluation times significantly (p ≤ 0.01) affected the hydraulic indices. After 400 h, the indices ranked as UD and FVC: WS > OPW + EP > OPW, and AFVR: OPW + EP = WS > OPW. Although OPW presented a low risk of clogging, the application of EP mitigated the obstruction and maintained higher uniformity by reducing clogging. These findings demonstrate that ultra-low-frequency electronic pulses are an innovative anti-clogging technology and provide insights for the sustainable application of produced water. Full article

Water scarcity in semi-arid regions necessitates accurate soil water modeling to optimize irrigation management. This study compares three HYDRUS-1D parameterization approaches—based on the drying-branch soil water retention curve (SWRC), wetting-branch SWRC (using Shani’s drip method), and inverse modeling—to simulating soil water content at 15 cm and 45 cm depths under center-pivot irrigation in a semi-arid region. Field experiments in three maize fields provided daily soil water, soil hydraulic, and meteorological data. Inverse modeling achieved the highest accuracy (NRMSE: 2.29–7.40%; RMSE: 0.006–0.023 cm³ cm⁻³), particularly at 15 cm depth, by calibrating van Genuchten parameters against observed water content. The wetting-branch approach outperformed the drying branch at the same depth, capturing irrigation-induced wetting processes more effectively. Statistical validation confirmed the robustness of inverse modeling in reproducing temporal patterns, while wetting-branch data improved deep-layer accuracy. The results demonstrate that inverse modeling is a reliable approach for soil water simulation and irrigation management, whereas the wetting-branch parameterization offers a practical, field-adaptable alternative. This study provides one of the first side-by-side evaluations of these three modeling approaches under real-world semi-arid conditions. Full article

Traditional methods of analyzing biofouling in emitters fail to capture the complexity and heterogeneity of their components. Therefore, the objective of this work was to develop and validate an innovative approach that integrates fractal metrics and scanning electron microscopy (SEM) to accurately characterize, quantify, and diagnose biofouling in drippers used with brackish water. For this purpose, tests were conducted on benches that applied brackish water and fresh water through drippers with a flow exponent (x) of 0.46 (NJ), 0.45 (SL), and 0.48 (ST) over 160 h. Biofouling was mapped using advanced diagnostics using SEM and factual metrics, and the results were analyzed using multivariate statistics. The results obtained present important findings for the study, detection, mapping, and proposal of mitigation measures for biofouling in drippers, presenting factual metrics that may be new indicators of clogging. Biofouling is a phenomenon resulting from the interaction between the spatial evolution of the obstructing material, emitter geometry, and irrigation water quality. The combination of SEM and fractal metrics has proven to be an advanced and innovative diagnostic tool for detecting the presence and distribution of biofouling, enabling clogging monitoring and creating more realistic scenarios in hydrodynamic studies to improve or develop emitter designs. Full article

Emitter clogging in drip irrigation systems is a recurring issue, affecting water application uniformity and system lifespan. This study investigated the anti-clogging performance of emitters and the accumulation patterns of solid particles in dripper labyrinths with varied geometric configurations, combining laboratory experimentation and computational fluid dynamics simulations. Fifteen labyrinth models were tested, divided into two groups: (Model A) emitters with well-defined vortexes and (Model B) emitters with uniform flow. The tests were conducted with solid particle concentrations of 125 and 500 mg L⁻¹ over 200 h of operation. The results showed that none of the emitters became clogged, even under severe particle concentration conditions. However, distinct deposition patterns were observed. Emitters with vortex formation accumulated particles in low-velocity zones, especially in the first baffles of the labyrinth. In contrast, emitters with uniform flow minimized sediment buildup, maintaining high velocities throughout the channel section. Simulations confirmed that the relationship between labyrinth geometry and flow velocity directly influences particle deposition. Dripper design strategies aimed at reducing low-velocity zones in the channel could help mitigate clogging risks. The findings of this study provide valuable guidelines for developing more clogging-resistant emitters, contributing to the improvement of drip irrigation systems. Full article

Water scarcity in Brazil’s semi-arid region necessitates the agricultural reuse of aquaculture effluents, although emitter clogging remains a challenge. This study evaluated clogging mitigation in drip irrigation systems using liquid anti-clogging fertilizer. The experiment employed a split–split–plot scheme with three water treatments (supply water, aquaculture effluent, and effluent with liquid fertilizer) and three emitter types (ST, SL, and GA), assessing performance over 360 h. A water quality analysis at 0, 160, and 360 h complemented hydraulic evaluations of the average flow rate variation and Christiansen uniformity coefficient measured every 40 h. Energy-dispersive X-ray spectroscopy, X-ray diffractometry, and scanning electron microscopy were used to characterize biofouling. The results showed that the liquid fertilizer mitigated the clogging by biofouling in the three types of emitters, but only the ST emitter presented acceptable hydraulic performance rates. There are relationships between the anti-clogging effect of the liquid fertilizer, the structural characteristics of the emitters, and the flow velocity inside the labyrinths. The SL dripper applying only aquaculture effluent presented the highest clogging rate due to biofouling. Agricultural reuse is a strategy for the rational use of water resources that is of great relevance for arid and semi-arid regions and can insert aquaculture into the circular economy. Full article

Flat drippers are widely used in agricultural irrigation systems to ensure precise water distribution. This study investigates the optimization of flat drippers through Computational Fluid Dynamics (CFDs) simulations, focusing on the channel geometry. These emitters have a particular configuration of the labyrinth channel appropriately shaped to ensure high turbulence and dissipation of the hydraulic load. CFDs techniques are particularly suitable to investigate the labyrinth design and optimization. Here, by analyzing seven different dripper models with varying dissipation channel sizes, the relationship between flow rate (liters per hour) and pipe pressure (kPa) was studied. Simulations were performed for six inlet pressures in the range between 50 and 175 kPa, with steps of 25 kPa, allowing for the derivation of the pressure–flow curve and the optimization of the emitter exponent. The value of the exponent is closely linked to the conformation of the channel and is standardized by the International Organization for Standardization (ISO) 9261:2004. Additionally, the influence of the labyrinth channel’s cross-sectional area on flow rate was examined, providing insights into design improvements for enhanced hydraulic performance. The proposed optimization could lead to significant water savings and enhanced agricultural productivity by improving the efficiency of irrigation systems. Full article

This study hypothesized that alternating fresh and saline irrigation with different dripper types would optimize water use while minimizing negative effects on soil bulk density (ρb) and maize growth. The field experiment was carried out to investigate the impact of the types of the dripper and the salinity of irrigation water rotation on the ρb, maize (Zea mays L.) growth, and yield using two kinds of drippers (turbo and spiral) and two levels of irrigation water with different salinity ratios (low, symbolized by L) and (high, symbolized by H). Irrigation water was added into three rotations (L, H), (H, L, H), and (L, H, L). Soil ρb increased by 22.63% under saline irrigation, while yield was 3.07% higher with turbo drippers compared to spiral drippers. The results displayed an increase in plant height, leaf area, and yield by using the (L, H, L) as compared to (L, H) and (H, L, H), respectively. These results suggest that alternating fresh and saline water could reduce freshwater usage by 50% while maintaining acceptable crop yields, making it a cost-effective solution for water-scarce regions. Full article

One of the most important advantages of drip irrigation is the possibility of achieving a high uniformity of water distribution. However, this uniformity can be reduced when using water with high iron content, which can cause drippers to clog. This study aimed to verify the efficiency of the chlorination, aeration, decantation and filtration processes carried out to remove the iron from irrigation water and to investigate the effect of iron on water distribution uniformity. Four similar irrigation systems with five models of drippers were installed. The results showed that (i) there was a significant difference in the drippers’ behavior in relation to susceptibility to clogging when using water with a high iron content; (ii) the use of disk filters alone was not able to promote significant reductions in the iron quantity as a way to prevent the clogging of drippers; and (iii) the use of aerators followed by sedimentation tanks made it possible to achieve a considerable improvement in the water application uniformity for drippers that were more sensitive to clogging caused by the use of water with high iron content. Full article

The aim of this study is to construct and validate an expert system to predict the adaptation of irrigation technologies, water-saving strategies, and monitoring tools by small-scale farmers in Egypt. The research investigates the impact of economic, educational, environmental, and social factors on adaptation rates. To build the expert system, extensive knowledge was collected from experts, key concepts were identified, and production rules were created to generate tailored scenarios. These scenarios utilize the empirical cumulative distribution function (ECDF), selecting the scenario with the highest ECDF as the optimal irrigation technology. This approach ensures well-informed, data-driven decisions that are tailored to specific conditions. The expert system was evaluated under the conditions of ten small farms in Egypt. The results indicate that water cost and availability are significant drivers of technology adaptation. Specifically, subsurface drip irrigation (SDI) demonstrated an adaptation percentage of 75% at high water costs, with probabilities of 0.67 and 0.33, while soil mulching (SM) showed a 75% adaptation rate with a probability of 0.33 in high-cost scenarios. Conversely, when water availability was high, the adaptation percentage for all techniques was zero, but it reached 100% adaptation with a probability of 0.76 for SM and SDI and a probability of 1 for variable number of drippers (VND) and the use of sensors as monitoring tools during water shortages. Educational attainment and professional networks enhance the adaptation of advanced technologies and monitoring tools, emphasizing the role of knowledge and community engagement. Environmental conditions, including soil texture and salinity levels, directly affect the choice of irrigation methods and water-saving practices, highlighting the need for localized solutions. The source of irrigation water, whether groundwater or surface water, influences the preference for water-saving technologies. The study underscores the importance of tailored approaches to address the challenges and opportunities faced by small farmers in Egypt, promoting sustainable agriculture and efficient water management. The evaluation findings reveal that SDI is the most favored irrigation technology, with a probability of 0.55, followed by variable number of drippers (VND) at 0.38 and ultralow drip irrigation (ULDI) at 0.07 across various scenarios for small farmers. Regulated deficit irrigation (RDI) and SM are equally preferred water-saving strategies, each with a probability of 0.50. Sensors emerged as the preferred monitoring tool, boasting a high probability of 0.94. The analysis reveals the critical roles of economic pressures, educational levels, environmental conditions, and social networks in shaping the adaptation of sustainable agricultural practices. Full article

Drip irrigation generates structural bodies in soil, forming layered structures with moisture content gradients. There are four typical soil moisture characteristic values in this concentric structure as saturation capacity (θs), field capacity (FC), 60% field capacity (60% FC), and 30% field capacity (30% FC). In this study, we simulated these four soil water characteristic values to conduct an indoor soil incubation experiment under three different incubation conditions: aerobic (O), aerobic with 10 pa acetylene (OC), and anaerobic (AO). The results indicate that in soil with saturated water content, denitrification under aerobic conditions leads to high N₂O emissions; in soil at field holding capacity, nitrification under aerobic conditions dominates low N₂O emissions, which is most conducive to N₂O reduction and greenhouse gas emission mitigation; in soil with 60% of field holding capacity, denitrification under anaerobic conditions leads to high N₂O emissions; and in soil with 30% of field holding capacity, microbial activity decreases, inhibiting nitrification, denitrification, and N₂O emissions. Our research has found that when conducting aerobic drip irrigation in soil at field capacity (FC), denitrification was reduced by 99%, nitrification was increased by 70%, and microbial activity was enhanced by 5%. Therefore, during drip irrigation, the position and flow rate of the dripper should be controlled to reduce soil water saturation areas, maintain soil aeration, control soil moisture content below field holding capacity, promote the nitrification process, reduce N₂O emissions, and improve soil nitrogen use efficiency. Our study elucidates the characteristics of nitrogen transformation and N₂O emissions across various soil moisture contents within the soil water structure under drip irrigation conditions, providing a scientific basis for the formulation of precise irrigation management practices and strategies for efficient soil nitrogen utilization. Full article

Although the bell pepper (Capsicum annuum L.) is sensitive to water stress, little information is available on proper irrigation management methods for bell pepper cultivation in the northern South Korean climate. We compared the effects of different irrigation methods on crop growth and water productivity in two bell pepper varieties (Maldonado and Nagano) at different irrigation durations (ending 3 h before sunset and ending 4 h before sunset) and irrigation quantities (placing two, three, and four drippers capable of irrigating at 2 L·h⁻¹) over approximately 280 days by performing in-depth analysis of various growth indicators. The plant height of Maldonado increased as the irrigation amount increased in all irrigation treatments of T1 and T2. In Nagano, there was no significant difference in plant height between D3 and D4. Overall, the irrigation treatments produced a higher difference in yield in Maldonado plants than in Nagano plants. WP tended to increase inversely to reduction in irrigation quantity in Groups 1 (May–June) and 4 (November–December) of both varieties, and response to irrigation stop time varied among the varieties. We inferred that the optimal irrigation method for bell pepper cultivation in northern South Korea is to supply irrigation at the D3 level and adjust the irrigation end time according to the variety and crop strength. Full article

Studies to improve the use of subsurface drippers in pasture formation are needed. Therefore, the objective of this study was to evaluate the germination and emergence of Sabia grass as a function of drippers installed at different depths. The study was conducted in pots in Viçosa, Minas Gerais State, Brazil. The experiment was conducted using a completely randomized design with four replicates. The experimental layout featured split plots over time, where the main plots consisted of three cultivation cycles and the subplots represented various dripper installation depths. The three sowing dates were 26 March, 12 April, and 29 April 2022. Drip tapes were installed at seven different depths: 0 (superficial), 5, 10, 15, 20, 25, and 30 cm. The results showed that the reduction in water potential, associated with increased temperature, resulted in lower performance of Sabia grass seeds. Seed germination and parameters related to germination speed were negatively impacted by the increase in dripper installation depth, with a 30–40% reduction in germination speed observed at depths greater than 15 cm. Drippers installed at 15–20 cm depth in clayey soil were ideal, providing a balance between reducing soil water evaporation and maintaining seedling emergence rates. Compared to surface installation, this depth improved seed performance by up to 25%, while enhancing operability and minimizing water loss. It is recommended to install drippers at a depth of 15–20 cm in subsurface drip irrigation systems in clayey soil areas to achieve benefits such as decreased soil water evaporation and improved operability compared to surface systems. Full article

Arid and semi-arid areas are suffering from declines in fresh water availability, making food security in these regions strongly dependent on the adaptability of agricultural production to the minimum usage of irrigation water. In response to this critical need, efforts have been directed towards enhancing irrigation efficiency and exploring innovative clay-based subsurface irrigation systems. These systems use clay materials as porous emitters and operate on the principle of capillary water movement from the pottery to the root zone, effectively reducing water evaporation and demonstrating significant water-saving potential. This article presents the results of a systematic literature review, with a specific focus on identifying recent developments and innovations in clay-based subsurface irrigation technologies, describing cases of applicability and indicating directions for future research. This review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and involved the screening of 233 articles that were found through searches on the databases Web of Science and Science Direct combined with searches of Google Scholar and citation searches. As a result, 58 research articles were investigated. The webtool Rayyan was used for the screening of the articles and the synthesis of the results. The spectrum of clay-based irrigation systems identified in the investigated articles includes traditional methods such as clay pot and clay pipe irrigation as well as more recent advancements in the field such as Subsurface Irrigation with Ceramic Emitters (SICE), Self-regulating Low-Energy Clay-based Irrigation (SLECI), and Ceramic Patch Subsurface Drip Irrigation Line (CP-SDIL) and pottery dripper technologies. This paper offers a comprehensive analysis of each irrigation system, highlighting their main characteristics, advantages, and limitations. Particular attention is paid to the reported outcomes related to yield responses, water use efficiency, and suitability for various agricultural applications. This review indicates as a primary benefit of these systems their potential to allow water conservation, which is especially advantageous in regions with a restricted irrigation water supply. However, a major drawback is the challenge of scaling these systems effectively. Hence, the recommended areas for future research centre on the necessity of substantial economic assessments of and discussion on the potential social impact to promote the scalability of clay-based irrigation systems. Full article