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Shiping Liu - One of the best experts on this subject based on the ideXlab platform.
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effect of saline water on cucumber cucumis sativus l yield and water use under drip Irrigation in north china
Agricultural Water Management, 2010Co-Authors: Shuqin Wan, Yaohu Kang, Dan Wang, Shiping LiuAbstract:Saline water has been included as an important substitutable resource for fresh water in Agricultural Irrigation in many fresh water scarce regions. In order to make good use of saline water for Agricultural Irrigation in North China, a semi-humid area, a 3-year field experiment was carried out to study the possibility of using saline water for supplement Irrigation of cucumber. Saline water was applied via mulched drip Irrigation. The average electrical conductivity of Irrigation water (ECiw) was 1.1, 2.2, 2.9, 3.5 and 4.2 dS/m in 2003 and 2004, and 1.1, 2.2, 3.5, 4.2 and 4.9 dS/m in 2005. Throughout cucumber-growing season, the soil matric potential at 0.2 m depth immediately under drip emitter was kept higher than −20 kPa and saline water was applied after cucumber seedling stage. The experimental results revealed that cucumber fruit number per plant and yield decreased by 5.7% per unit increase in ECiw. The maximum yield loss was around 25% for ECiw of 4.9 dS/m, compared with 1.1 dS/m. Cucumber seasonal accumulative water use decreased linearly over the range of 1.5–6.9% per unit increase in ECiw. As to the average root zone ECe (electrical conductivity of saturated paste extract), cucumber yield and water use decreased by 10.8 and 10.3% for each unit of ECe increase in the root zone (within 40 cm away from emitter and 40 cm depths), respectively. After 3 years Irrigation with saline water, there was no obvious tendency for ECe to increase in the soil profile of 0–90 cm depths. So in North China, or similar semi-humid area, when there is no enough fresh water for Irrigation, saline water up to 4.9 dS/m can be used to irrigate field culture cucumbers at the expense of some yield loss. © 2010 Published by Elsevier B.V.
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effect of saline water on cucumber cucumis sativus l yield and water use under drip Irrigation in north china
Agricultural Water Management, 2010Co-Authors: Shuqin Wan, Yaohu Kang, Dan Wang, Shiping LiuAbstract:Saline water has been included as an important substitutable resource for fresh water in Agricultural Irrigation in many fresh water scarce regions. In order to make good use of saline water for Agricultural Irrigation in North China, a semi-humid area, a 3-year field experiment was carried out to study the possibility of using saline water for supplement Irrigation of cucumber. Saline water was applied via mulched drip Irrigation. The average electrical conductivity of Irrigation water (ECiw) was 1.1, 2.2, 2.9, 3.5 and 4.2Â dS/m in 2003 and 2004, and 1.1, 2.2, 3.5, 4.2 and 4.9Â dS/m in 2005. Throughout cucumber-growing season, the soil matric potential at 0.2Â m depth immediately under drip emitter was kept higher than -20Â kPa and saline water was applied after cucumber seedling stage. The experimental results revealed that cucumber fruit number per plant and yield decreased by 5.7% per unit increase in ECiw. The maximum yield loss was around 25% for ECiw of 4.9Â dS/m, compared with 1.1Â dS/m. Cucumber seasonal accumulative water use decreased linearly over the range of 1.5-6.9% per unit increase in ECiw. As to the average root zone ECe (electrical conductivity of saturated paste extract), cucumber yield and water use decreased by 10.8 and 10.3% for each unit of ECe increase in the root zone (within 40Â cm away from emitter and 40Â cm depths), respectively. After 3 years Irrigation with saline water, there was no obvious tendency for ECe to increase in the soil profile of 0-90Â cm depths. So in North China, or similar semi-humid area, when there is no enough fresh water for Irrigation, saline water up to 4.9Â dS/m can be used to irrigate field culture cucumbers at the expense of some yield loss.
Shuqin Wan - One of the best experts on this subject based on the ideXlab platform.
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effect of saline water on cucumber cucumis sativus l yield and water use under drip Irrigation in north china
Agricultural Water Management, 2010Co-Authors: Shuqin Wan, Yaohu Kang, Dan Wang, Shiping LiuAbstract:Saline water has been included as an important substitutable resource for fresh water in Agricultural Irrigation in many fresh water scarce regions. In order to make good use of saline water for Agricultural Irrigation in North China, a semi-humid area, a 3-year field experiment was carried out to study the possibility of using saline water for supplement Irrigation of cucumber. Saline water was applied via mulched drip Irrigation. The average electrical conductivity of Irrigation water (ECiw) was 1.1, 2.2, 2.9, 3.5 and 4.2 dS/m in 2003 and 2004, and 1.1, 2.2, 3.5, 4.2 and 4.9 dS/m in 2005. Throughout cucumber-growing season, the soil matric potential at 0.2 m depth immediately under drip emitter was kept higher than −20 kPa and saline water was applied after cucumber seedling stage. The experimental results revealed that cucumber fruit number per plant and yield decreased by 5.7% per unit increase in ECiw. The maximum yield loss was around 25% for ECiw of 4.9 dS/m, compared with 1.1 dS/m. Cucumber seasonal accumulative water use decreased linearly over the range of 1.5–6.9% per unit increase in ECiw. As to the average root zone ECe (electrical conductivity of saturated paste extract), cucumber yield and water use decreased by 10.8 and 10.3% for each unit of ECe increase in the root zone (within 40 cm away from emitter and 40 cm depths), respectively. After 3 years Irrigation with saline water, there was no obvious tendency for ECe to increase in the soil profile of 0–90 cm depths. So in North China, or similar semi-humid area, when there is no enough fresh water for Irrigation, saline water up to 4.9 dS/m can be used to irrigate field culture cucumbers at the expense of some yield loss. © 2010 Published by Elsevier B.V.
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effect of saline water on cucumber cucumis sativus l yield and water use under drip Irrigation in north china
Agricultural Water Management, 2010Co-Authors: Shuqin Wan, Yaohu Kang, Dan Wang, Shiping LiuAbstract:Saline water has been included as an important substitutable resource for fresh water in Agricultural Irrigation in many fresh water scarce regions. In order to make good use of saline water for Agricultural Irrigation in North China, a semi-humid area, a 3-year field experiment was carried out to study the possibility of using saline water for supplement Irrigation of cucumber. Saline water was applied via mulched drip Irrigation. The average electrical conductivity of Irrigation water (ECiw) was 1.1, 2.2, 2.9, 3.5 and 4.2Â dS/m in 2003 and 2004, and 1.1, 2.2, 3.5, 4.2 and 4.9Â dS/m in 2005. Throughout cucumber-growing season, the soil matric potential at 0.2Â m depth immediately under drip emitter was kept higher than -20Â kPa and saline water was applied after cucumber seedling stage. The experimental results revealed that cucumber fruit number per plant and yield decreased by 5.7% per unit increase in ECiw. The maximum yield loss was around 25% for ECiw of 4.9Â dS/m, compared with 1.1Â dS/m. Cucumber seasonal accumulative water use decreased linearly over the range of 1.5-6.9% per unit increase in ECiw. As to the average root zone ECe (electrical conductivity of saturated paste extract), cucumber yield and water use decreased by 10.8 and 10.3% for each unit of ECe increase in the root zone (within 40Â cm away from emitter and 40Â cm depths), respectively. After 3 years Irrigation with saline water, there was no obvious tendency for ECe to increase in the soil profile of 0-90Â cm depths. So in North China, or similar semi-humid area, when there is no enough fresh water for Irrigation, saline water up to 4.9Â dS/m can be used to irrigate field culture cucumbers at the expense of some yield loss.
Thomas C Harmon - One of the best experts on this subject based on the ideXlab platform.
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a receding horizon control algorithm for adaptive management of soil moisture and chemical levels during Irrigation
Environmental Modelling and Software, 2009Co-Authors: Yeonjeong Park, Jeff S Shamma, Thomas C HarmonAbstract:The capacity to adaptively manage Irrigation and associated contaminant transport is desirable from the perspectives of water conservation, groundwater quality protection, and other concerns. This paper introduces the application of a feedback-control strategy known as Receding Horizon Control (RHC) to the problem of Irrigation management. The RHC method incorporates sensor measurements, predictive models, and optimization algorithms to maintain soil moisture at certain levels or prevent contaminant propagation beyond desirable thresholds. Theoretical test cases are first presented to examine the RHC scheme performance for the control of soil moisture and nitrate levels in a soil Irrigation problem. Then, soil moisture control is successfully demonstrated for a center-pivot system in Palmdale, CA where reclaimed water is used for Agricultural Irrigation. Real-time soil moisture, temperature, and meteorological data were streamed wirelessly to a field computer to enable autonomous execution of the RHC algorithm. The RHC scheme is demonstrated to be a viable strategy for achieving water reuse and Agricultural objectives while minimizing negative impacts on environmental quality.
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a receding horizon control algorithm for adaptive management of soil moisture and chemical levels during Irrigation
Center for Embedded Network Sensing, 2009Co-Authors: Yeonjeong Park, Jeff S Shamma, Thomas C HarmonAbstract:The capacity to adaptively manage Irrigation and associated contaminant transport is desirable from the perspectives of water conservation, groundwater quality protection, and other concerns. This paper introduces the application of a feedback-control strategy known as Receding Horizon Control (RHC) to the problem of Irrigation management. The RHC method incorporates sensor measurements, predictive models, and optimization algorithms to maintain soil moisture at certain levels or prevent contaminant propagation beyond desirable thresholds. Theoretical test cases are first presented to examine the RHC scheme performance for the control of soil moisture and nitrate levels in a soil Irrigation problem. Then, soil moisture control is successfully demonstrated for a center-pivot system in Palmdale, CA where reclaimed water is used for Agricultural Irrigation. Real-time soil moisture, temperature, and meteorological data are streamed wirelessly to a field computer to enable autonomous execution of the RHC algorithm. The RHC scheme is demonstrated to be a viable strategy for achieving water reuse and Agricultural objectives while minimizing negative impacts on environmental quality.
Gaiqiang Yang - One of the best experts on this subject based on the ideXlab platform.
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a flexible decision support system for Irrigation scheduling in an Irrigation district in china
Agricultural Water Management, 2017Co-Authors: Gaiqiang Yang, Mo LiAbstract:Decision support systems for Agricultural Irrigation scheduling are generally designed and developed for specific Agricultural regions or Irrigation districts. Flexible Irrigation scheduling decision support tools which are applicable to various Irrigation districts are desired for sound Agricultural Irrigation planning and management. This study attempts to develop a flexible Irrigation scheduling decision support system (FIS-DSS) which could be easily customized and adapted to different Irrigation districts and cases, and thus repeated software development is not needed. The developed FIS-DSS includes a user interface, a knowledge base, and an inference engine. As the core module of the FIS-DSS, the inference engine uses specific computer programs to maneuver the knowledge base, and the knowledge base was used to store and provide data, knowledge, information and rules for the inference engine. As the core of the FIS-DSS, a fuzzy interval programming model with multiple objectives and constrains was developed with advantages in data processing, model flexibility, alternative solving algorithm and friendly result display. The system users can obtain suitable water allocation schemes for each crop on a temporal and spatial fashion by modifying the model inputs and scenarios through the software interface. A case study was introduced to demonstrate the functions and operations of the FIS-DSS, and useful information has been generated to provide a practical guidance for Agricultural water allocation and utilization.
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An uncertainty-based framework for Agricultural water-land resources allocation and risk evaluation
Agricultural Water Management, 2016Co-Authors: Mo Li, Ping Guo, Vijay P. Singh, Gaiqiang YangAbstract:Agricultural land and water resources are simultaneously declining due to population growth and economic expansion, which emphasizes the need for optimal allocation of these resources to balance socioeconomic development and water conservation. This study develops a framework for allocation of Agricultural land-water resources and risk evaluation under uncertainty. The framework is capable of fully reflecting multiple uncertainties expressed as intervals and probability distributions, considering the connections of Agricultural water and land resources. The developed framework will be helpful for managers in gaining insights into the tradeoffs between system benefits and constraint-violation risks, permitting an in-depth analysis of risks of Agricultural Irrigation water shortage under various violating probabilities. The framework is applied for optimization of Agricultural water and land resources in the middle reaches of Heihe River basin. A series of water and land allocation results under different flow levels and violating probabilities were obtained and analyzed in detail through optimally allocating limited water and land resources to different Irrigation areas and crops. Comparison with actual conditions shows that both the “net benefit per unit water” and “net benefit per unit land” increase which will demonstrate the feasibility and applicability of the developed framework. In addition, probability distributions of water allocation under various flow levels are generated to help decision makers learn detailed water distribution information and thus help make comprehensive Irrigation schemes in the planning horizon under uncertainty. Results of evaluation of Agricultural Irrigation water shortage risks indicate that the water shortage risks in the middle reaches of Heihe River basin are in the category of acceptable risk level or brink risk level. The developed framework can be valuable for providing a reliable decision aid for optimal water and land resources allocation, and can ensure that the management policies and plans are made with reasonable consideration of both system benefits and risks.
Peiying Hong - One of the best experts on this subject based on the ideXlab platform.
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removal of bacterial contaminants and antibiotic resistance genes by conventional wastewater treatment processes in saudi arabia is the treated wastewater safe to reuse for Agricultural Irrigation
Water Research, 2015Co-Authors: Nada I Aljassim, Mohd Ikram Ansari, Moustapha Harb, Peiying HongAbstract:Abstract This study aims to assess the removal efficiency of microbial contaminants in a local wastewater treatment plant over the duration of one year, and to assess the microbial risk associated with reusing treated wastewater in Agricultural Irrigation. The treatment process achieved 3.5 logs removal of heterotrophic bacteria and up to 3.5 logs removal of fecal coliforms. The final chlorinated effluent had 1.8 × 10 2 MPN/100 mL of fecal coliforms and fulfils the required quality for restricted Irrigation. 16S rRNA gene-based high-throughput sequencing showed that several genera associated with opportunistic pathogens (e.g. Acinetobacter , Aeromonas , Arcobacter , Legionella , Mycobacterium , Neisseria , Pseudomonas and Streptococcus ) were detected at relative abundance ranging from 0.014 to 21 % of the total microbial community in the influent. Among them, Pseudomonas spp. had the highest approximated cell number in the influent but decreased to less than 30 cells/100 mL in both types of effluent. A culture-based approach further revealed that Pseudomonas aeruginosa was mainly found in the influent and non-chlorinated effluent but was replaced by other Pseudomonas spp. in the chlorinated effluent. Aeromonas hydrophila could still be recovered in the chlorinated effluent. Quantitative microbial risk assessment (QMRA) determined that only chlorinated effluent should be permitted for use in Agricultural Irrigation as it achieved an acceptable annual microbial risk lower than 10 −4 arising from both P. aeruginosa and A. hydrophila . However, the proportion of bacterial isolates resistant to 6 types of antibiotics increased from 3.8% in the influent to 6.9% in the chlorinated effluent. Examples of these antibiotic-resistant isolates in the chlorinated effluent include Enterococcus and Enterobacter spp. Besides the presence of antibiotic-resistant bacterial isolates, tetracycline resistance genes tetO, tetQ, tetW, tetH, tetZ were also present at an average 2.5 × 10 2 , 1.6 × 10 2 , 4.4 × 10 2 , 1.6 × 10 1 and 5.5 × 10 3 copies per mL of chlorinated effluent. Our study highlighted that potential risks associated with the reuse of treated wastewater arise not only from conventional fecal indicators or known pathogens, but also from antibiotic-resistant bacteria and genes.
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environmental and public health implications of water reuse antibiotics antibiotic resistant bacteria and antibiotic resistance genes
The Journal of Antibiotics, 2013Co-Authors: Peiying Hong, Nada I Aljassim, Mohd Ikram Ansari, Roderick I MackieAbstract:Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for Agricultural Irrigation. The use of reclaimed water as an alternative water source for Agricultural Irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for Agricultural Irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the “perfect microbial storm”. Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water.