Water-saving Irrigation Research Articles

Water Deficit Diagnosis of Winter Wheat Based on Thermal Infrared Imaging

Field experiments were conducted to analyze the effectiveness of the crop stress index (CWSI) obtained by infrared thermal imaging to indicate crop water status, and to determine the appropriate CWSI threshold range for wheat at different growth stages. The results showed that the sensitivity of plant physiological parameters to soil water was different at different growth stages. The sensitivity of stomatal conductance (Gs) and transpiration rate (Tr) to soil water was higher than that of leaf relative water content (LRWC) and photosynthetic rate (Pn). The characteristics of plant physiology and biomass (yield) at each growth stage showed that the plant production would not suffer from drought stress as long as the soil water content (SWC) was maintained above 57.0% of the field water capacity (FWC) during the jointing stage, 63.0% of the FWC during the flowering stage and 60.0% of the FWC during the filling stage. Correlation analysis showed that the correlation of CWSI with Gs, Tr and Pn was lower than that with LRWC and SWC at the jointing stage. CWSI was extremely significantly negatively correlated with SWC and LRWC (p < 0.01), but significantly negatively correlated with Gs, Tr and Pn (p < 0.05). At the flowering stage, CWSI was extremely significantly negatively correlated with all physiological and soil parameters (p < 0.01). The regression analysis showed that the CWSI of winter wheat was correlated with biomass (grain yield) in a curvilinear relationship at each growth stage. When the CWSI increased to a certain extent, the biomass and yield showed a decreasing trend with the increase in CWSI. Comprehensive analysis of all indexes showed that CWSI can be used as a decision-making index to guide the water-saving irrigation of winter wheat, as long as the CWSI threshold of plants was maintained at 0.26–0.38 during the jointing stage, 0.27–0.32 during the flowering stage and 0.30–0.36 during the filling stage, which could not only avoid the adverse effects of water stress on crop production, but also achieve the purpose of water saving.

Effect of agricultural management practices on rice yield and greenhouse gas emissions in the rice–wheat rotation system in China

Agricultural management practices (AMPs) have the potential to significantly enhance crop yield, albeit with the possible side effect of escalating greenhouse gas emissions. Few studies have undertaken a comprehensive quantification of the impact of AMPs on crop production and soil GHG, particularly in identifying the optimal AMPs for rice cultivation within rice-wheat rotation system. Here, we combined data analysis and keyword search methods on 1433 individual experimental observations from 172 studies on diverse soil types in the subtropical monsoon climate zone of China to assess the impact of AMPs on rice yield, CH4 and N2O emissions, total greenhouse gas emissions (TGHGE). We focused on four key AMPs: mineral N fertilizer management (including ordinary N fertilizer and slow−/controlled-release fertilizer (SCRF)), organic material management (incorporating organic fertilizer, biochar amendment, and straw return), water-saving irrigation, and no-tillage. Our result showed the rice yield ranged from 2525 to 31,196 kg ha−1, and mineral N fertilizer and organic material management boosted rice yield by 2.84–16.19 % and 2.47–8.52 %, respectively. In terms of N2O emissions, biochar amendment resulted in a decrease of 13.05 %, while ordinary N fertilizer, organic fertilizer, and water-saving irrigation led to increases of 63.16 %, 136.66 %, and 37.41 %, respectively. The implementation of SCRF, water-saving irrigation, and no-tillage significantly curtailed CH4 (6.83 %–35.91 %) and TGHGE (6.22 %–20.59 %). Conversely, organic fertilizer and straw return significantly escalated CH4 emissions by 102.20 % and 33.64 % and TGHGE by 85.03 % and 32.40 %. Rice yield and GHG emissions are mainly influenced by variables such as soil bulk density, pH, soil organic carbon, soil texture, mean annual temperature, and total nitrogen. Our study demonstrates that the application of SCRF, water-saving irrigation, and no-tillage can effectively reduce GHG without compromising yield. These practices are particularly effective under climatic and soil conditions of rice-wheat rotation systems in China, thereby contributing to the sustainable rice farming.

A Comparative Study of the Driving Factors of Water Resources Use Efficiency in China’s Agricultural and Industrial Sectors

The efficient use of water resources has become an important topic in China. Research on measurement and driving factors is the foundation for improving water resources use efficiency (WRUE). In this paper, the super-efficiency slacks-based measure (SE-SBM) model is used to measure the WRUE of China from 2005 to 2021. The agricultural carbon emissions and chemical oxygen demand (COD) in industrial wastes are taken as undesirable by-products. The driving factors of WRUE are discussed with use of the Tobit regression model. The results show that China’s agricultural WRUE ranges from 1.185 in Jilin to 0.687 in Ningxia. In the industrial sector, the WRUE ranges from 1.399 in Beijing to Jiangxi 0.212. The economic structure and development level, water resources endowment, government influence and environmental regulation, agricultural planting scale and urbanization rate have impacts on WRUE. Precautionary measures need to be applied to prevent inefficient WRUE caused by the declining share of the industrial sector in the economic structure. More financial support should be focused on water-saving irrigation in agriculture and energy and resource efficiency in industry. The organizational structure and technological advantages of urbanization should also be emphasized in efforts to improve water efficiency.

Concept and importance of soil moisture potentials in agriculture

The root design of crops in soils has a direct impact on yield potentials, which are controlled by soil moisture potential and its balancing components, because crops only benefit from transpiration sharing. The soil moisture potential, which governs the movement of soil moisture based on differential energy states, is a significant factor. In general, the kinetic energy of a soil moisture flow rate is too tiny to be taken into account. Due to its location in a force field that may help to increase water use efficiency, the corresponding potential energy of soil moisture is what defines its energy state. Significant irrigation water loss happens during flood irrigation through evaporation, seepage or drainage. On the other hand, tensiometer-based soil moisture potential delineation contributes significantly to irrigation water savings. Therefore, having greater yield potentials as well as improved lives in water-stressed regions of the world requires a proper understanding of soil moisture potentials, its components, and their relationship with soil water flow for reducing water footprints particularly of water stressed regions.

The influence of technology perceptions on farmers' water-saving irrigation technology adoption behavior in the North China Plain

Abstract The application and promotion of water-saving irrigation technology are of great significance for maintaining food security and the sustainable development of agricultural water resources. Based on the characteristics of integrated agricultural technologies, a binary logistic model was used to analyze the impact of technology perception on farmers' adoption behavior regarding water-saving irrigation technologies using data from surveys of 775 wheat and maize farmers in the North China Plain. The results show the following: the perceived ease of use of technology significantly contributes to farmers' water-saving irrigation technology adoption behavior, but the effect of the perceived usefulness of technology is not significant. Government regulation plays a moderating role in the impact of the perceived ease of use of technology on the adoption of water-saving irrigation technologies by farmers. In addition to the perceived ease of use of technology and technology training, large-scale farmers are influenced by government advocacy and technology subsidies, while smallholders are mainly influenced by the perceived usefulness of technology. Therefore, the focus of future work should be on improving farmers' perceptions of the ease of use of water-saving irrigation technologies, expanding the scope of technical training and technical subsidies, and strengthening government advocacy and education.

Assessing the feasibility of sprinkler irrigation schemes and their adaptation to future climate change in groundwater over-exploitation regions

Promoting appropriate water-saving irrigation is an important pathway to alleviate groundwater overexploitation in irrigated agriculture. Whether an alternative irrigation method is feasible relies on quantitative assessments of its impacts on crop yield and hydrological cycle, especially in the groundwater overdraft area that faces a dilemma between water scarcity and food security. Using a groundwater-module-improved SWAT (Soil & Water Assessment Tool) model, five GCMs (General Circulation Models) projections of CMIP6 (Coupled Model Intercomparison Project 6), and a linear programming algorithm, sprinkler irrigation was simulated, evaluated, and optimized in a representative global groundwater mining location, the piedmont plain of the North China Plain. During the historical period (1993–2012), the results showed that, in general, sprinkler irrigation had advantages in benefiting crop transpiration of winter wheat and reducing percolation, hence improving water use efficiency with reference to traditional surface irrigation. Specifically, compared to traditional surface irrigation schemes, winter wheat yields increased by 12%− 14% with a 225 mm irrigation quota; they were stable with a 150 mm irrigation quota; but they decreased by 4% with a 75 mm irrigation quota. The shallow groundwater tables would decline at an average rate of 1.29 m/yr, 0.83 m/yr, and 0.35 m/yr, respectively, under sprinkler irrigation with 225 mm, 150 mm, and 75 mm irrigation quotas. Future climate changes (increased precipitation, air temperatures, and CO2 concentration) would bring effects of improving wheat yield by 6%− 7% and increasing groundwater vertical recharge by 58%− 122% in 2030–2049. The variations of predicted future shallow groundwater tables were − 0.37 m/yr, 0.01 m/yr, and 0.40 m/yr with the 225 mm, 150 mm, and 75 mm irrigation quotas, respectively, in the SSP2–4.5 scenario; and the corresponding results were − 0.45 m/yr, − 0.05 m/yr, and 0.34 m/yr in the SSP5–8.5 scenario. The optimization results showed that sprinkler irrigation could be implemented in approximately 50% of the study area to achieve shallow groundwater equilibrium and stable wheat production simultaneously in the near future. And the dominant sprinkler irrigation schedule after optimization was found to be scheme S3 (irrigation frequency for wheat was 5 times) with a limited irrigation quota of 150 mm. This study provides detailed data for planning sprinkler water-saving irrigation regimes and groundwater pumping strategies in China’s breadbasket, as well as a reference for global irrigated agriculture with over-drafted aquifers to balance groundwater conservation and grain production.

Assessment of Blue Water Migration and Efficiency in Water-Saving Irrigation Paddy Rice Fields Using the Water Flow Tracking Method

Although irrigation systems largely sustain global agricultural production, their efficiency is often alarmingly low. While irrigation water (blue water) is critical for the water-saving irrigation of rice with a high water demand, the process and efficiency of irrigation water utilization need clarification. In this study, we examined the three commonly used irrigation and drainage patterns (frequent shallow irrigation (FSI), wet and shallow irrigation (WSI), and rain-catching and controlled irrigation (RCI)) in rice fields. We developed a tracking method for irrigation water flow decomposition, which includes irrigation water evapotranspiration (IET), irrigation water drainage (IDR), irrigation water leakage (IPC), and irrigation water field residual (IRE). Using this method, we established an irrigation water efficiency evaluation index system and a comprehensive evaluation method. Our tracking method is relevant to describing the irrigation water performance under varying irrigation and drainage patterns. The results revealed that the average irrigation water input for the three irrigation and drainage patterns between 2015 and 2018 was roughly 312.5 mm, wherein IET accounted for 148 mm. However, more than 50% of the irrigation water outflow, comprising IDR, IPC, and IRE, exceeded the total amount of irrigation water input. The mean values of the gross irrigation efficiency (GIE), net irrigation efficiency (NIE), and effective consumption ratio (ECR) for all treatments in the three-year period were 0.63, 0.47, and 0.75, respectively. Additionally, the irrigation water use efficiency was significantly higher in dry years compared to wet years. The fuzzy composite rating values of the three irrigation and drainage models from 2015 to 2018 were RCI, WSI, and FSI, in descending order, under varying precipitation conditions. The RCI patterns maintained a high composite rating value (greater than 3.0) under different precipitation conditions. Previous efficiency calculations disregarded the blue–green water migration process and did not differentiate the blue–green water flow direction in agricultural fields, creating significant biases in the outcomes. This study’s method offers a new approach to evaluate the use of blue water resources in farmland.

Estimating maize evapotranspiration based on hybrid back-propagation neural network models and meteorological, soil, and crop data.

Crop evapotranspiration is a key parameter influencing water-saving irrigation and water resources management of agriculture. However, current models for estimating maize evapotranspiration primarily rely on meteorological data and empirical coefficients, and the estimated evapotranspiration contains uncertainties. In this study, the evapotranspiration data of summer maize were collected from typical stations in Northern China (Yucheng Station), and a back-propagation neural network (BP) model for predicting maize evapotranspiration was constructed based on meteorological data, soil data, and crop data. To further improve its accuracy, the maize evapotranspiration model was optimized using three bionic optimization algorithms, namely the sand cat swarm optimization (SCSO) algorithms, hunter-prey optimizer (HPO) algorithm, and golden jackal optimization (GJO) algorithm. The results showed that the fusion of meteorological, soil moisture, and crop data can effectively improve the accuracy of the maize evapotranspiration model. The model showed higher accuracy with the hybrid optimization model SCSO-BP compared to the stand-alone BP neural network model, with improvements of 2.7-4.8%, 17.2-25.5%, 13.9-26.8%, and 3.3-5.6% in terms of R2, RMSE, MAE, and NSE, respectively. Comprehensively compared with existing maize evapotranspiration models, the SCSO-BP model presented the highest accuracy, with R2 = 0.842, RMSE = 0.433 mm/day, MAE = 0.316 mm/day, NSE = 0.840, and overall global evaluation index (GPI) ranking the first. The results have reference value for the calculation of daily evapotranspiration of maize in similar areas of northern China.

Evaluation of net carbon sequestration and ecological benefits from single biochar-incorporated sorghum farmland systems in saline-alkali areas of Inner Mongolia, China

Biochar is widely recognized as a soil amendment to reduce greenhouse gas emissions and enhance soil carbon storage in agroecosystems; however, the systematic focus on carbon balance and ecological benefits in cropping systems remains unclear in saline-alkali areas under water-saving irrigation. Here, a 2-yr field experiment with carbon footprint method was conducted to determine soil carbon budgets, biochar carbon efficiency performance, and the economic and ecological benefits of mulched drip-irrigated sorghum production, in an arid salinized region of Inner Mongolia, China. Corn straw-derived biochar dosages of 0 (CK), 15 (B15), 30 (B30), and 45 (B45) t hm−2 were just applied into the soil in the first crop growing season. A single application of biochar to soil significantly reduced CO2 emissions for the current and subsequent crop-growing seasons, with 13.1%, 16.7%, and 12.5% reductions for B15, B30, and B45, respectively. Compared with the non-biochar control plots, B15, B30, and B45 also increased NPP by 36.7%, 38.4%, and 27.1%, respectively. The actual effects on improving net carbon sequestration for B15, B30, and B45 in the first year were higher than those in the second year, with mean increases of 1.27, 1.47, and 1.36 times, respectively; however, the efficiencies of biochar for fixing carbon per biochar dosage input for B15 were 72.8% and 64.1% higher than those of B30 and B45, respectively. Net profits were significantly improved by 57.2–87.1% by biochar treatments. The environmental benefits of biochar carbon trading revenues for B15, B30, and B45 increased by 105.9%, 162.1%, and 109.6%, respectively. The minimum observation for carbon productivity and the maximum measurements for both the economic and ecological benefits were B15. The B15 also significantly increased sorghum yield and grain number. Results demonstrate that biochar application in the current growing season helps reduce soil carbon emissions, increases net carbon sequestration for current and subsequent sorghum agroecosystems, and enhances net profit and ecological benefits. The optimal positive synergistic effect was observed at a biochar application rate of 15 t hm−2 for reducing soil carbon emissions, increasing crop production, and improving the ecological environment.

Impact of Agricultural Cooperatives on Farmers’ Collective Action: A Study Based on the Socio-Ecological System Framework

Agricultural cooperatives greatly influence agricultural and rural modernization in China. Based on 381 farmer samples in the arid Tarim River Basin, this empirical study aimed to construct an index system for the exploration of the relationship between cooperatives and farmers’ collective action by using the Socio-Ecological System framework. The results showed that agricultural cooperatives helped to empower farmers to act collectively. Agricultural cooperatives, with the mechanisms of collective decision making, institutional constraints, and internal supervision, could realize the integration of resources required for farmers’ collective action and promote the sharing of risks and benefits. By providing financing support and a platform for resource integration, cooperatives could reduce constrains induced by economic difference among farmers; enhance village leadership, organization, and coordination; and promote the accumulation of social capital and villagers’ sense of identity with the village. Particularly, cooperatives could support farmers to adopt water-saving irrigation technologies and reduce their over-dependence on chemical pesticides and fertilizers, thus promoting farmers’ collective action. Therefore, the development of agricultural cooperatives will help enhance farmers’ collective action, promote the modernization of rural governance, and realize rural revitalization.

Research on the application of water measuring technology in water-saving irrigation

Abstract The rise of agricultural Internet of Things (IoT) technologies is transforming traditional farming into modern, sustainable agriculture through scientific advancements. This study introduces a novel fusion calibration algorithm that combines the least squares method and back propagation neural networks to enhance water measurement accuracy in agricultural settings. By developing a nonlinear function, the algorithm progressively minimizes the discrepancies between detected results and actual data until satisfactory accuracy is achieved. An irrigation experiment on wolfberry plants in City H utilizing this optimized technology demonstrated a near-perfect correlation between the automatic measurements (3.56 m/s) and the actual flow rates (3.55 m/s) recorded by a flow meter, with an error margin of just 0.282%. Furthermore, the study observed a steady increase in the water utilization coefficient in farmland irrigation from 0.54 in 2011 to 0.589 in 2020, indicating enhanced water efficiency and conservation.

Sustainable Green Development: Water-Saving Irrigation Technologies

In the context of global climate change and increasing demand for natural resources, sustainable development requires the introduction of innovative technologies that contribute to the conservation and rational use of water resources. This article aims to examine water-saving irrigation technologies. The efficiency of the sprinkler irrigation system is affected by the wind flow and evaporation. Therefore, the comparison of designed and measured values of discharge from a nozzle and throwing radius of three sprinklers for 6 pressured head were done. Experiment was conducted at Uchxoz district, Tashkent region, Uzbekistan with latitude 69.248903 and longitude 41.037240. The place is 2 ha and experiment were at wheat crop. Irrigation system has been taken from Chirchik river. Sprinkler system installed with 9 to 12 m distances connect with a soil condition and slope. Because of importance of natural conditions, especially wind drift and radiation connect with the evaporation, research was performed at these losses. Furthermore, the calculation of wind drift and evaporation losses based on the observed values was calculated. The measured values of the discharges were lower as the designed one in all cases from 71% to 83%. Furthermore, we can conclude that the smallest differences were observed during the experiment with highest radius with smallest pressure head. The real radius of wetter area was from 80% to 88% of the designed radius by producer. The results showed the need to use the higher number of sprinklers or higher pressure to irrigate the required area.

Spatiotemporal variation of the major meteorological elements in an agricultural region: A case study of Linyi City, Northern China

<abstract> <p>Evaporation is a key element of the water and energy cycle and is essential in determining the spatial and temporal variations of meteorological elements. In particular, evaporation is crucial for thoroughly understanding the climate variations of a region. In this study, we discussed evaporation, precipitation, and temperature by adopting Linyi City in Shandong Province, China, which is an important agricultural region, as a research case. Linear regression analysis, the empirical orthogonal decomposition function, and the Morlet wavelet function were used to reveal the trends, spatiotemporal modes, and multi-time scale characteristics of the three climate factors and provide a theoretical basis for the efficient use of climate resources in the future development of regional agriculture. Results showed that the precipitation (2.09 mm/a) and temperature (0.04 ℃/a) in Linyi City exhibited a synchronous growth trend. Conversely, evaporation (−6.47 mm/a) showed a decreasing trend and the evaporation paradox because of the considerable decrease in evaporation energy. Regional development of water-consuming agriculture in consideration of global warming is a key point for improving water use efficiency in Linyi City. In terms of spatial distribution, precipitation was dominated by the first mode wherein low precipitation was observed at the early stage, and high precipitation occurred at the late stage. The first mode was supplemented by the second mode wherein an inverse phase change occurred in the southeast-northwest direction. Large interannual fluctuations were observed only in Yinan County. Temperature exhibited a pattern of warming change with high homogeneity. Evaporation demonstrated obvious heterogeneity and was dominated by two major modes, and the difference in evaporation between Junan County and the other regions of Linyi City was large. Therefore, the local regional climate changes in Yinan and Junan should be given attention. All three meteorological elements showed interannual and interdecadal variations in the short (5 a), medium (16 a), and long (25 a) terms, with precipitation, temperature, and evaporation dominated by 16 a, 24 a, and 31 a, respectively. In the short-term future, the regional precipitation and temperature in Linyi will experience decrements that are above the multiyear average, and evaporation will increase to above the multiyear average. Given the changing trends of precipitation, temperature, and evaporation, urgent requirements for the regional development of efficient water-saving irrigation and the promotion of digital agriculture should be proposed.</p> </abstract>

Effects of biofertilizer and water-saving irrigation interactions on the leaf photosynthesis and plant growth of tomatoes

Effects of biofertilizer and water-saving irrigation interactions on the leaf photosynthesis and plant growth of tomatoes

Computational fluid dynamics and artificial neural networks for modelling lined irrigation canals with low‐density polyethylene and cement concrete liners

AbstractThis 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.

Surface temperature adjustment in METRIC model for monitoring crop water consumption in North China Plain

Evapotranspiration is the real water consumption element in agricultural water management. In order to improve the efficiency of agricultural water use and maintain the sustainable development of agriculture, more and more attention has been paid to the improvement of monitoring and management of farmland evapotranspiration. In this study, MODIS data and the Temperature Vegetation Dryness Index (TVDI) were used in the METRIC model to estimate evapotranspiration for winter wheat and summer corn in the North China Plain. In order to decrease the error caused by the spatial heterogeneity of air temperature in the estimation of evapotranspiration, based on the characteristics of cold pixels with surface temperatures close to their air temperature, the TVDI was used to assist the selection of cold pixels and obtain the spatial variation trend of air temperature with latitude from all cold pixels in the study area. The influence of the spatial heterogeneity of air temperature on the surface temperature at the time of the satellite overpass was corrected accordingly, thereby the estimation accuracy of evapotranspiration was improved. A METRIC-TVDI model was established and the evapotranspiration of winter wheat and summer corn in Hebei Plain was estimated from 2017 to 2019. The average evapotranspiration of the winter wheat over these three years were 361 mm, 327 mm and 354 mm respectively, and that of summer corn were 394 mm, 388 mm and 405 mm respectively. Based on the farmland water balance, the irrigation water consumption (evapotranspiration minus precipitation) of winter wheat and summer corn rotation were 324 mm, 134 mm and 360 mm respectively. This kind of crop rotation pattern consumed more groundwater for irrigation, especially the winter wheat. In order to realize the balance of groundwater between exploitation and replenishment in Hebei Plain, more water-saving irrigation technologies should be adopted to reduce the evapotranspiration and improving water use efficiency.

Performance of a Drip Irrigation System under the Co-Application of Water, Fertilizer, and Air

The co-application of water, fertilizer, and air is a new water-saving irrigation method based on drip irrigation technology, which can effectively alleviate the phenomenon of soil rhizosphere hypoxia, improve water and fertilizer utilization efficiency, and inhibit the clogging of irrigation equipment in drip irrigation systems. The performance of drip irrigation systems is one of the important factors affecting the effectiveness of the co-application of water, fertilizer, and air. However, the impact of factors such as the aeration method, fertilization device, and working parameters on the performance of drip irrigation systems for the co-application of water, fertilizer, and air is still unclear. Therefore, based on two typical aeration methods, i.e., micro-nano and Venturi aeration, the performance of a drip irrigation system under the co-application of water, fertilizer, and air was studied by comparing and analyzing the effects of different aeration methods, working pressures of the drip irrigation system, and the pressure difference between the inlet and outlet of fertilizer irrigation on the spatial distribution uniformity of water, fertilizer, and air in the drip irrigation pipeline network. The results showed that the pressure difference between the inlet and outlet of fertilization irrigation had no significant impact on system performance, while the working pressure significantly affected system performance. Compared with the effective effect of Venturi aeration on system performance, micro-nano aeration can significantly affect drip irrigation system performance and effectively improve drip irrigation system performance. The micro-nano-aerated drip irrigation system with the co-application of water, fertilizer, and air under a working pressure of 0.1 MPa has better system performance. The research results are of great significance for revealing the mechanism underlying the impact of the co-application of water, fertilizer, and air on the performance of drip irrigation systems and constructing efficient drip irrigation technology for the co-application of water, fertilizer, and air.

Evaluation of Water Balance and Water Use Efficiency with the Development of Water-Saving Irrigation in the Yanqi Basin Irrigation District of China

Irrigation water is the main type of water consumption in the Yanqi Basin irrigation district of Xinjiang, which is an oasis-type irrigation district in the arid region of Northwest China. With the continuous expansion of cultivated areas, there is an increasing demand for irrigation water, resulting in an irrigation efficiency paradox and the phenomenon of “the more water-saving, the more water-scarce”. In this study, the water balance method and the improved IWMI (International Water Management Institute) water balance method were used with remote sensing and statistical data from 1980 to 2020 to analyze the changes in the irrigation water supply, consumption, and loss for improvement in irrigation water use efficiency (IWUE) in the Yanqi Basin. The results showed that there was an upward trend in the cultivated land area in the irrigation district of Yanqi Basin, as monitored with remote sensing from 1980 to 2020, and the values from the remote sensing data were higher than those from the yearbooks. According to the remote sensing data, the arable land area in the irrigation district increased from 1672 km2 in 1980 to 2494 km2 in 2020, thus showing a trend of expansion. The traditional water use efficiency in the irrigation district showed an increasing trend. The lowest value for the field water-use coefficient was 0.70 in 1998, and it exceeded to 0.81 from 2009 to 2020. The canal water-use coefficient was as low as 0.50 in 1998 and increased from 0.54 in 2009 to 0.82 in 2020. The irrigation water-use coefficient increased from 0.35 in 1998 to 0.68 in 2020, with a general upward trend. In this study, the water consumption ratio indicator DFg (depleted fraction), determined using the improved water balance method, increased from 0.8390 in 1980 to 0.8562 in 2020, although it showed an overall decreasing trend, and the average was 0.8436. Cultivated land’s actual irrigation water consumption per unit area reached the highest value of 8.41 × 106 m3/hm2/a in 2011 and the minimum value of 4.01 × 106 m3/hm2/a in 2020, and from 1980 to 2020 it showed a decreasing trend, while the total water diversion showed an increasing trend due to the continuous expansion of arable land. From 1980 to 2020, water diversion into the irrigation district changed from 1.214 km3 to 1.000 km3, and it reached a maximum of 1.593 km3 in 2000; water diversion into the irrigation district showed an overall upward trend. The positive impact of the post-2000 water conservation phase with the adaptation of water-saving irrigation technology was clear, as the findings showed an increase in IWUE in the Yanqi Basin irrigation district. These results provide a theoretical basis for breaking the paradox of irrigation efficiency, which can be used in the water resource management of irrigation districts.

Efficient Water-Saving Irrigation, Space Efficiency and Agricultural Development — Study Based on Spatial Stochastic Frontier Model

Efficient Water-Saving Irrigation, Space Efficiency and Agricultural Development — Study Based on Spatial Stochastic Frontier Model

English

Lack of water is the main problem facing agriculture and crop production in arid and semi-arid regions. Deficit irrigation is widely used to optimize water application efficiency under drought conditions in arid areas. The purpose of the work is to estimate the efficiency of SALTMAD model for simulating soil moisture dynamics, water application efficiency, and seed yield under three Deficit Irrigation Strategies (DIS) [DIS1 (100% Full Irrigation (FI)), DIS2 (80% FI), and DIS3 (60% FI)] with six treatments of Integrated Nitrogen-Fertilization (INF) including [INF1 (100% MN + 0% ON), INF2 (80% MN + 20% ON), INF3 (60% MN + 40% ON), INF4 (40% MN+ 60% ON), INF5 (20% MN + 80% ON) and INF6 (0% MN + 100% ON)]. Moreover, the best strategy of deficit irrigation with the best treatment of integrated nitrogen fertilizer will be selected for improving soil hydro-physical properties, water productivity, and seed yield in semi-arid soil regions without any water stress. Field experiment was conducted during 2020/2021 and 2021/2022 at the Research Farm of National Research Center (NRC) at Nubaryia Region, Al Buhayrah Governorate, Egypt. Soil hydro-physical properties including infiltration rate (IR), and soil moisture dynamics were measured in the field. In addition, soil moisture dynamics, water application efficiency, seed yield, and water productivity of bean were simulated using the SALTMAD model and compared with thatmeasured in the field under the above conditions. The results observed that the best treatment that led to increased water application efficiency and seed yield was at DIS2 (80% FI) with INF4 (40% MN+ 60% ON) compared to DIS1 (100% FI), and DIS3 (60% FI). In this strategy, seed yield productivity increased by 43.4% in the first season, and 34.7% in the second season as well as saving irrigation water by up to 20% for cultivated faba bean in sandy soil without any water stress. The usage of balance a combination of mineral and organic fertilizers can be used to compensate for deficit irrigation by improving infiltration rate, water holding capacity, water application efficiency, and seed yield. The SALTMAD model can be used to simulate soil moisture dynamics, water application efficiency, seed yield, and water productivity with little calculation error under different deficit irrigation strategies and integrated nitrogen fertilization in arid and semi-arid areas with sandy soil.