Special Issue "Advances in Sprinkler Irrigation Systems and Water Saving"

A special issue of Water (ISSN 2073-4441). This special issue belongs to the section "Water, Agriculture and Aquaculture".

Deadline for manuscript submissions: closed (4 September 2022) | Viewed by 6802

Special Issue Editors

Prof. Dr. Haijun Yan
E-Mail Website
Guest Editor
College of Water Resources & Civil Engineering, China Agricultural University, Beijing 100083, China
Interests: sprinkler irrigation technology; low-pressure sprinkler; center pivot irrigation system; variable rate irrigation; fertigation; water saving and yield increase
Prof. Dr. Xingye Zhu
E-Mail Website
Guest Editor
Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013, China
Interests: sprinkler irrigation systems and water saving

Special Issue Information

Dear Colleagues,

Water shortage has become one of the main factors restricting food security and sustainable development around the world. Agriculture is the largest water user, and its low effective utilization coefficient of agricultural irrigation water makes water-saving irrigation of great significance. As one of the highest-efficiency water-saving irrigation techniques, sprinkler irrigation has been widely promoted all over the world due to its advantages of strong adaptability, labor saving, and yield increase. Although there are many advantages to sprinkler irrigation, its potential shortcomings cannot be ignored, such as high investment costs, sensitive to environmental factors, and excessive energy consumption. Today, new technical methods such as smart irrigation, variable rate irrigation, and solar-powered irrigation have emerged to deal with these problems. In the future, sprinkler irrigation technology will continue to play a key role in water saving and yield increase, environmental protection, and sustainable development.

The purpose of this Special Issue of Water is to collect the latest advances in sprinkler irrigation systems and water saving, specifically including the following aspects, but not limited to:

  • Evaluation of sprinkler irrigation performance;
  • Optimization of sprinkler irrigation systems;
  • New technology and equipment;
  • Fertilization;
  • Variable rate irrigation;
  • Low-pressure sprinkler irrigation.

Prof. Dr. Haijun Yan
Prof. Dr. Xingye Zhu
Guest Editors

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Keywords

  • sprinkler irrigation
  • micro irrigation
  • drip irrigation
  • hydraulic performance
  • low-pressure sprinkler
  • new technology and equipment
  • reclaimed water irrigation
  • smart irrigation
  • variable rate irrigation
  • fertigation
  • water saving
  • yield increase
  • irrigation management

Published Papers (10 papers)

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Research

Article
Spray Characteristics and Parameter Optimization of Orifice Arrangement for Micro-Sprinkling Hoses
Water 2022, 14(20), 3260; https://doi.org/10.3390/w14203260 - 15 Oct 2022
Viewed by 480
Abstract
The spraying width and uniformity coefficient are important for the design of a micro-sprinkling hose. In this study, experiments were conducted on the water application intensity distribution for an individual orifice and multiple groups of orifices under three different working pressures (41, 69 [...] Read more.
The spraying width and uniformity coefficient are important for the design of a micro-sprinkling hose. In this study, experiments were conducted on the water application intensity distribution for an individual orifice and multiple groups of orifices under three different working pressures (41, 69 and 103 kPa). In the test of an individual orifice, the spraying angles varied from 40° to 90°. The results showed that the water application intensity distributions of an individual orifice were well fitted by a two-dimensional Gaussian distribution. Further study indicated that the bimodal Gaussian distribution model performed well on tracking the two-dimensional features of the water application intensity distribution, with the determination coefficient R2 > 0.90 and the standard root mean square error NRMSE < 30%. It was revealed that the fitting parameters of the two-dimensional Gaussian distribution model had physical meaning and were directly related to the strength and location of the water application intensity distributions. Based on the analysis of these fitting parameters, it was found that the water application intensity distribution of an individual orifice was affected by the pressure, spraying angle and orifice area, among which the spraying angle was the most sensitive factor. By establishing a linear relationship between the fitting parameters and the spraying angles, the water application intensity distribution of an individual orifice for any spraying angle could be predicted by the Gaussian model. Therefore, the water application intensity distribution of multiple groups of orifices could be calculated by overlapping the water application intensity distributions of the individual orifices. The Monte Carlo method was used in this study to determine the maximum spraying width and uniformity coefficient by generating different groups of orifice arrangement for micro-sprinkling hoses. Eventually, the optimized orifice arrangement was recommended for the better design of micro-sprinkling hoses. Full article
(This article belongs to the Special Issue Advances in Sprinkler Irrigation Systems and Water Saving)
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Article
Optimal Sprinkler Application Rate of Water–Fertilizer Integration Machines Based on Radial Basis Function Neural Network
Water 2022, 14(18), 2838; https://doi.org/10.3390/w14182838 - 12 Sep 2022
Viewed by 545
Abstract
The application rate for sprinkler irrigation of water–fertilizer integration machines is an important technical parameter for efficient operation. If the value is too large, the equipment will produce runoff; if it is too small, the equipment will run too long and waste energy. [...] Read more.
The application rate for sprinkler irrigation of water–fertilizer integration machines is an important technical parameter for efficient operation. If the value is too large, the equipment will produce runoff; if it is too small, the equipment will run too long and waste energy. Therefore, it is necessary to provide a feasible scientific and theoretical basis for developing a reasonable application rate. In this study, a mathematical model of soil infiltration for sprinkler irrigation with water and fertilizer integration machines was developed. Soil water accumulation time for different soil’s initial water content, bulk density, sprinkler application rate and soil texture were derived by the finite element method, and these data were used as a training database for the neural network. To make the neural network convenient for predicting the optimal application rate of sprinkler irrigation (the maximum application rate of sprinkler irrigation without runoff) in practice, the time of waterlogging, was multiplied by the optimal application rate of sprinkler irrigation to obtain the total irrigation volume. The optimal application rate of the sprinkler irrigation prediction model of radial basis function (RBF) neural network was constructed with total irrigation water, soil bulk density, initial water content and soil texture as inputs and compared with BP neural network and generalized regression neural network. The highest prediction accuracy of RBF neural network was obtained, and its average relative error was 0.11. To verify the accuracy of the RBF neural network application rate of sprinkler irrigation prediction model in real life, a sprinkler experiment was conducted in the laboratory of Guangzhou University, and the collected soil and lawn of Guangzhou University were used to simulate the actual environment. The results showed that the relative error between the RBF neural network prediction results and the actual values was generally around 10%, while for a total irrigation volume of 58 mm, the optimal application rate of sprinkler irrigation calculated with the model was 42 (mm/h), which can save 70% of irrigation time compared to the case of using the stable infiltration rate of soil as the application rate of sprinkler irrigation without water and fertilizer. Water and fertilizer losses were not observed. This indicates that the model proposed in this study is of practical value in determining the optimum application rate of sprinkler irrigation for water–fertilizer integration machines. Full article
(This article belongs to the Special Issue Advances in Sprinkler Irrigation Systems and Water Saving)
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Article
Analysis of Irrigation Performance of a Solid-Set Sprinkler Irrigation System at Different Experimental Conditions
Water 2022, 14(17), 2641; https://doi.org/10.3390/w14172641 - 27 Aug 2022
Viewed by 460
Abstract
The complexity of assessing the irrigation performance of a solid-set sprinkler irrigation system implies analyzing factors of the sprinkler features, the spacing among sprinklers, the evaluation heights, the meteorological variables and the crop. In this research, a number of solid-set experiments with impact [...] Read more.
The complexity of assessing the irrigation performance of a solid-set sprinkler irrigation system implies analyzing factors of the sprinkler features, the spacing among sprinklers, the evaluation heights, the meteorological variables and the crop. In this research, a number of solid-set experiments with impact sprinklers were evaluated with different operating conditions and a number of models of irrigation uniformity (CUC) and losses due to drift and wind (WDEL) were assessed at different catch-can heights. Statistical analysis and predictive models were performed for each variable analyzed. The results showed that ND 5035 and SEN 4023 impact sprinklers that presented the lowest variability in water distributions patterns based on the standard deviations of the irrigation depth collected in the catch can (0.85 mm/h). These sprinklers had demonstrated the best CUC values (mean of 86%) with low WDEL averages (lower than 9%). Regarding the CUC analysis, there was a statistically significant difference in measuring the irrigation uniformity from 1 to 2 m catch-can height based on the analysis of 396 solid-set experiments of different research works. Future research could be focused on more experimental conditions analyzing the effects of the irrigation on the crop agronomic development and its yield. Full article
(This article belongs to the Special Issue Advances in Sprinkler Irrigation Systems and Water Saving)
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Article
Analysis of Flow Channel Structure Parameter and Optimization Study on Tooth Spacing of Drip Irrigation Tape
Water 2022, 14(11), 1694; https://doi.org/10.3390/w14111694 - 25 May 2022
Viewed by 556
Abstract
The flow channel structure is the main factor affecting the hydraulic performance, anti-clogging and energy dissipation performance of drip irrigation tape. Proper exploring of the performance-related but hard-to-measure structure parameters in the flow channel emitter of drip irrigation tape is imperative. However, the [...] Read more.
The flow channel structure is the main factor affecting the hydraulic performance, anti-clogging and energy dissipation performance of drip irrigation tape. Proper exploring of the performance-related but hard-to-measure structure parameters in the flow channel emitter of drip irrigation tape is imperative. However, the traditional studying methods may lead to large systematic errors and human errors, resulting in inaccurate estimations of the parameters and an unreasonable design. This paper aims to find an effective way to optimize the most significant channel structural parameter through studying 18 kinds of drip irrigation belts commonly used in the agricultural irrigation field. Unigraphics NX and Spaceclaim were applied to measure the eight main structure parameters of the selected drip irrigation tapes. The one critical parameter that affects the emitter hydraulic performance—tooth spacing—was found by Principal Component Analysis (PCA). Therefore, we designed three plans where the tooth spacing decreased by 0.1, 0.2, and 0.29 mm to 1.36, 1.26, and 1.17 mm, respectively, and, finally, formed two types of flow channels. Flow channel 1 with a tooth base is represented by Plan 1 and Plan 2, and flow channel 2 without a tooth base is represented by Plan 3. Then, computational fluid dynamics (CFD) was used to simulate the flow characteristics of the emitters in the three plans. The results demonstrate that flow channel 2 without a tooth base, represented by Plan 3, has a greater kinetic energy and hydraulic performance than flow channel 1. Compared with the control group, the changes in Plan 3 were the most obvious, with the changes in the flow index, flow coefficient, and average flow rate by −14.50%, −5.08%, and 12.50%, respectively. The flow indexes in the three plans are all less than 0.5, while the smallest of Plan 3 is 0.395. Therefore, the hydraulic performance of flow channel 2 represented by Plan 3 is better. The narrowing of the tooth spacing makes the space for vortexing between the serrated teeth smaller. The flow velocity in Plan 3 is generally increased by 3 m/s from 2.3 to 4.1 m/s, becoming more uniform. Due to a high velocity of the water flow and less vortexing, the deposition of suspended solids in the flow channel is avoided to a certain extent, and for the flow channel in Plan 3, the improvement in the hydraulic performance is greater than the reduction in the energy dissipation performance. The ratio of the decrease in the flow index to the increase in the average outflow of the emitter in Plan 3 is 1.16:1. In conclusion, the overall performance of Plan 3 is optimal for all schemes. Flow channel 2 can improve the hydraulic performance and reduce the production costs. Therefore, this study could provide a theoretical induction for inner drip irrigation tape application and production. Full article
(This article belongs to the Special Issue Advances in Sprinkler Irrigation Systems and Water Saving)
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Article
Quantifying the Spatial Distribution of Soil Nitrogen under Long-Term Drip Fertigation
Water 2022, 14(9), 1337; https://doi.org/10.3390/w14091337 - 20 Apr 2022
Viewed by 463
Abstract
Quantifying the spatial distribution of nitrogen (N) in the soil under long-term drip fertigation events is essential for the optimal regulation of drip fertigation systems. In this study, a greenhouse soil that had been under drip irrigation for 20 years was selected as [...] Read more.
Quantifying the spatial distribution of nitrogen (N) in the soil under long-term drip fertigation events is essential for the optimal regulation of drip fertigation systems. In this study, a greenhouse soil that had been under drip irrigation for 20 years was selected as the research object, and soil samples were collected from the 0–50 cm soil depth. The concentrations of N in the soil samples were measured and their spatial distribution characteristics were quantified by classical statistical analysis and multifractal analysis. The results showed that long-term drip fertigation and the influence of natural factors resulted in the nitrate N mainly accumulating in the shallow layer of the soil and within a distance from the drip irrigation belt, and the spatial heterogeneity gradually decreased with increasing depth. The content of ammonium N was low, and its distribution was observed in the whole section. Multifractal analysis indicated that the Δα value of nitrate N and inorganic N gradually increased with the increase in the research scale, i.e., the spatial heterogeneity gradually increased, and it did not appreciably change for ammonium N. Meanwhile, the local high value region was the main factor leading to the spatial heterogeneity of N, and this dominant effect gradually increased with increasing depth. Multifractal analysis can effectively reflect the local information of the N spatial distribution in the soil and provide a more detailed description of the spatial heterogeneity of soil properties. Full article
(This article belongs to the Special Issue Advances in Sprinkler Irrigation Systems and Water Saving)
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Article
Structure–Biodegradability Relationship of Nonylphenol Isomers in Two Soils with Long-Term Reclaimed Water Irrigation
Water 2022, 14(8), 1258; https://doi.org/10.3390/w14081258 - 13 Apr 2022
Cited by 1 | Viewed by 482
Abstract
Nonylphenol (NP), as one of the typical endocrine disrupter chemicals (EDCs), has a high detection concentration and frequency in reclaimed water. This research focused on the degradation of NP isomers in two typical reclaimed water irrigation fields in Daxing, China, and Florida, USA. [...] Read more.
Nonylphenol (NP), as one of the typical endocrine disrupter chemicals (EDCs), has a high detection concentration and frequency in reclaimed water. This research focused on the degradation of NP isomers in two typical reclaimed water irrigation fields in Daxing, China, and Florida, USA. The results showed that the half-lives of NP isomer degradation in the soil of China and Florida were 2.03–8.66 d and 5.16–11.83 d, respectively. The degradation of NP isomers was structure-specific. Isomers of NP5, NP2, NP11, and NP3 had the highest degradation rates in the two soils; NP12, NP7, and NP6 were the isomers with medium degradation rates; and NP4, NP1, NP10, NP9, and NP8 had the slowest degradation rates. Steric hindrance and mean information index for the magnitude of distance (IDWbar) were found to be the better indexes for measuring the degradation of NP isomers compared with the length of the side chain, the type of the substitute, and the molecular connectivity. This study offers insights into the characteristics of NP isomers and two reliable indicators for measuring the degradation of NP isomers, which could provide data support for the environmental fate and the health risk assessment of NP in the future. Full article
(This article belongs to the Special Issue Advances in Sprinkler Irrigation Systems and Water Saving)
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Article
Spatiotemporal Distribution of Water and Nitrogen in Border Irrigation and Its Relationship with Root Absorption Properties
Water 2022, 14(8), 1253; https://doi.org/10.3390/w14081253 - 13 Apr 2022
Viewed by 476
Abstract
The spatiotemporal distribution characteristics of water and nitrogen in the soil profile are essential influencing factors that determine the development of crop root systems. The purpose of this study was to clarify the inter-row and inter-tree variability in soil moisture in the apple [...] Read more.
The spatiotemporal distribution characteristics of water and nitrogen in the soil profile are essential influencing factors that determine the development of crop root systems. The purpose of this study was to clarify the inter-row and inter-tree variability in soil moisture in the apple root zone, and to determine the effective root diameter ranges of apple trees that influence water and nitrogen absorption. The method used was a 2-year border irrigation experiment carried out in a traditional apple orchard in Zuncun, Shanxi Province, China. Dynamic variations in the soil moisture between trees within the row (perpendicular to the direction of border irrigation) and between rows (along the direction of border irrigation) were continuously measured from 2015 to 2016, and a specific soil profile was excavated to analyze the distribution characteristics of soil water, nitrogen, and roots with different diameters. The results showed obvious variations in soil moisture in the surface soil of 0–30 cm, and the soil moisture content between rows was 5% higher than that between trees within the row. The root length density in the soil between trees within the row was 33.5% higher than that in the soil between rows. Bivariate correlation analysis showed that the correlation between the root system and nitrogen and water was ranked from highest to lowest: total nitrogen (0.741) > nitrate nitrogen (−0.36) > soil moisture (−0.273). The correlation coefficient between trees within the row was higher than that between rows. Lower soil moisture between trees within the row resulted in increased root biomass and more active uptake activity between trees within the row. There were different significant correlations between the specific root diameter and the contents of soil water and nitrogen, showing that the 1.5 mm diameter roots correlated with the water content, whereas the 2.0 mm diameter roots correlated with the nitrogen content. The findings of this study provide a deeper understanding of the absorption mechanism of crop roots for soil water and nitrogen. Full article
(This article belongs to the Special Issue Advances in Sprinkler Irrigation Systems and Water Saving)
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Article
Dimensional Analysis Model of Head Loss for Sand Media Filters in a Drip Irrigation System Using Reclaimed Water
Water 2022, 14(6), 961; https://doi.org/10.3390/w14060961 - 18 Mar 2022
Viewed by 613
Abstract
A new model was developed to predict head loss in sand media filters. Sand filters with six different media using reclaimed water were used to measure head losses at different flow rates in the laboratory. The parameters influencing head losses were considered to [...] Read more.
A new model was developed to predict head loss in sand media filters. Sand filters with six different media using reclaimed water were used to measure head losses at different flow rates in the laboratory. The parameters influencing head losses were considered to be the uniformity coefficient, the effective diameter, the sand mass, the filtration velocity, the pollution load, and the water viscosity. A dimensional analysis method was used to develop the model. A comparison between the predicted and the measured head losses showed close agreement with a correlation coefficient of 91.7%, reaching a significance level of p < 0.001. The results showed that the model might give satisfactory predictions within the following range of operational and filter structure parameters: uniformity coefficient 1.48–3.31; effective diameter 0.41–2.1 mm; pollution load 0.0169–4.2049 kg, filtration velocity 0.0038–0.0398 m/s. Full article
(This article belongs to the Special Issue Advances in Sprinkler Irrigation Systems and Water Saving)
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Article
Optimizing Center Pivot Irrigation to Regulate Field Microclimate and Wheat Physiology under Dry-Hot Wind Conditions in the North China Plain
Water 2022, 14(5), 708; https://doi.org/10.3390/w14050708 - 23 Feb 2022
Cited by 1 | Viewed by 644
Abstract
The dry-hot wind climate is one of the major agro-meteorological disasters associated with high temperature, low humidity, and specific wind forces, which seriously affects the yield of wheat in the North China Plain. A field experiment was conducted to investigate the field microclimate, [...] Read more.
The dry-hot wind climate is one of the major agro-meteorological disasters associated with high temperature, low humidity, and specific wind forces, which seriously affects the yield of wheat in the North China Plain. A field experiment was conducted to investigate the field microclimate, net photosynthetic rate, chlorophyll content of flag leaves, grain filling rate, and wheat yield after sprinkler misting under the condition of a dry-hot wind climate in the 2018 and 2019 seasons. Two travel speeds, full and half speed, and the corresponding irrigation amounts of 2.5 and 5 mm were used by a center pivot irrigation system during dry-hot wind conditions. A treatment without irrigation was applied as a control. The results showed that the air temperature and relative air humidity were greatly improved within 60 min after irrigation, especially in the upper part of the canopy. The net photosynthetic rate of flag leaves under 5 mm irrigation was higher than that under 2.5 mm irrigation during the middle and late grain filling periods. The adverse effects of dry-hot wind on the chlorophyll content of the flag leaves were mainly concentrated in the late grain filling stage. In the two years of the experiment, the average 1000-grain weights of 5 and 2.5 mm of irrigation treatments were 4.3 and 2.8% higher, and the grain yields were 5.8 and 3.3% higher, respectively, than those of the non-irrigated yields. Overall, applying a small amount of water between 12:00–14:00 with a center pivot before the occurrence of dry-hot wind is an effective means to regulate the field microclimate and produce more yield in the North China Plain. Full article
(This article belongs to the Special Issue Advances in Sprinkler Irrigation Systems and Water Saving)
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Article
Modelling of Water Drop Movement and Distribution in No Wind and Windy Conditions for Different Nozzle Sizes
Water 2021, 13(21), 3006; https://doi.org/10.3390/w13213006 - 26 Oct 2021
Cited by 1 | Viewed by 847
Abstract
A numerical model was developed to determine the water drop movement and mean droplet size diameter at any distance from a sprinkler as a function of nozzle size and pressure. Droplet size data from 4, 5, 6, and 7 mm nozzle sizes verified [...] Read more.
A numerical model was developed to determine the water drop movement and mean droplet size diameter at any distance from a sprinkler as a function of nozzle size and pressure. Droplet size data from 4, 5, 6, and 7 mm nozzle sizes verified the model. Data for model prediction were generated throughout lab experiments. The results demonstrated that the correlation between the observed and predicted droplet size diameter values for all the nozzle sizes and pressures is quite good. Nozzle size and pressure had a major influence on droplet size. Higher pressure produced smaller droplets over the entire application profile. The wetted distance downwind from the sprinkler increased as wind velocity increased, for example at a constant working pressure of 300 kPa, at wind speeds of 3.5 m/s and 4.5 m/s, 20% and 32% of the total volume exceeded the wet radius respectively. Larger droplets (3.9–4.5 mm), accounting for 3.6% and 6.3% of the total number of distributed droplets, respectively. The model can also predict the droplet size distribution at any wind direction overall the irrigated pattern. Full article
(This article belongs to the Special Issue Advances in Sprinkler Irrigation Systems and Water Saving)
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