The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Yaohu Kang - One of the best experts on this subject based on the ideXlab platform.
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lateral flushing regime for managing emitter clogging under Drip Irrigation with saline groundwater
Irrigation Science, 2017Co-Authors: Di Feng, Yaohu KangAbstract:Water scarcity forces saline water to be used in the Bohai Rim Region, China. However, emitter clogging is a persistent and widespread problem in Drip Irrigation systems when irrigating with saline water. To find a suitable lateral flushing regime for Drip Irrigation systems using saline groundwater, the objective of this study was to evaluate the effect of five different lateral flushing frequencies. The lateral flushing frequencies were at 1-, 5-, 10-, 30- and 50-day intervals using saline and fresh groundwater. The total duration of Irrigation was 100 days, with a total application of 122 h for each water source. The Drip Irrigation system consisted of hydrocyclone separator, disc filters and screen filters with inline-labyrinth emitters and thin-wall laterals. The results of this experiment are trusted only at such conditions, and show that emitter discharge and uniformity decreased in all treatments. Flushing laterals every 5 days was adequate to control emitter clogging for Drip Irrigation systems applying the fresh groundwater, while the other three less flushing frequencies failed to prevent clogging. Emitters in the saline groundwater treatments clogged earlier and more severely than those in the fresh groundwater treatments. Five flushing frequencies under Drip Irrigation using saline groundwater failed to prevent clogging. Based on the findings above, to better control emitter clogging, freshwater is suggested to be used to flush laterals following Irrigation with saline groundwater and longer flushing duration is recommended, which needs further study.
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changes of soil microbial characteristics in saline sodic soils under Drip Irrigation
Journal of Soil Science and Plant Nutrition, 2014Co-Authors: S H Liu, Yaohu KangAbstract:A field experiment was carried out to study the changes of soil bacteria, fungi and actinomycetes in saline-sodic soils for different numbers of cultivated years under Drip Irrigation. The Drip Irrigation had substantial effects on levels of bacteria, fungi and actinomycetes. With increased number of cultivated years under Drip Irrigation, the soil biological properties were greatly improved. After three years of cultivation, the respective increases in the levels of bacteria, fungi and actinomycetes were 103.7, 72.7 and 58.2 times those of uncultivated land. In the vertical direction, the colony forming units of bacteria, fungi and actinomycetes all decreased with increased soil depth. We forecast that the soil microbial characteristics in Drip-irrigated saline-sodic soils should match those of natural Leymus chinensis grassland after 6-7 years of cultivation.
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assessment of soil enzyme activities of saline sodic soil under Drip Irrigation in the songnen plain
Paddy and Water Environment, 2013Co-Authors: Yaohu Kang, Shuqin Wan, Shuhui Liu, Ruoshui WangAbstract:A field experiment was carried out to research the changes and spatial distributions of soil enzyme activities in saline-sodic soil for a different number of cultivated years under Drip Irrigation. The distributions of alkaline phosphatase, urease, and sucrase activities within 40 cm in both horizontal and vertical directions of the emitter in saline-sodic soils planted with Leymus chinensis for 1st, 2nd, and 3rd year were studied. A mathematical method was used to determine the relationships between soil enzyme activities and soil environmental factors contain the electrical conductivity of saturated-soil extract, pH value, available nutrient, and organic carbon. Alkaline phosphatase, urease, and sucrase activities all increased with cultivated years in saline-sodic soil under Drip Irrigation: from 4.5, 1.39 and 19.39 to 20.25, 3.17, and 61.33 mu g g(-1) h(-1), respectively, after planting L. chinensis for 3 year. Alkaline phosphatase, urease, and sucrase activities all decreased with increased horizontal and vertical distance from the emitter. After 3 year of Drip Irrigation, the correlations between soil enzyme activities and soil environment factors had stronger correlations than in the unreclaimed land. After 4-6 years, the soil enzyme activities should attain the level of the natural L. chinensis grassland.
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effect of Drip Irrigation on soil nutrients changes of saline sodic soils in the songnen plain
Paddy and Water Environment, 2013Co-Authors: Shuhui Liu, Yaohu Kang, Shuqin Wan, Shufang Jiang, Shiping Liu, Jiaxia SunAbstract:A field experiment was carried out to research the changes and spatial distributions of soil nutrients in saline–sodic soil for different number of cultivated years under Drip Irrigation. The distributions of available potassium (AK), available phosphorus (AP), nitrate nitrogen (NO3−–N), ammonium nitrogen (NH4+–N), as well as the amount of total nitrogen (TN), total phosphorus (TP) and organic carbon (OC) in the 0–40 cm soil layers in saline–sodic soils planted with Leymus chinensis for 1, 2, and 3 years were studied. The results showed that the distance from the emitter had an obvious effect on soil nutrients. Drip Irrigation had substantial effects on levels of AK, AP, and NO3−–N. The contents of AK, AP, and NO3−–N were very high in the area near the emitter in the horizontal direction. In the vertical direction, levels of all of the available and total soil nutrients decreased with increased soil depth. Levels of AK, AP, NO3−–N, NH4+–N, TN, TP, and OC all increased with continued cultivation of crops on saline–sodic soil using Drip Irrigation. Compared to the nutrients found in soils from the natural L. chinensis grasslands, the contents of AK and TP were higher in the Drip-irrigated soils, although the contents of AP, NO3−–N, and NH4+–N were broadly comparable. Given the rate of improvements in nutrient levels, we forecast that the nutrients in Drip-irrigated saline–sodic soils should match those of the natural L. chinensis grasslands after 3–6 years of cultivation.
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germination and growth of puccinellia tenuiflora in saline sodic soil under Drip Irrigation
Agricultural Water Management, 2012Co-Authors: Shuhui Liu, Yaohu Kang, Shuqin Wan, Shufang Jiang, Zhichun Wang, Zhengwei Liang, Ruoshui WangAbstract:Field experiments were conducted to investigate the effects of Drip Irrigation on seed germination and Puccinellia tenuiflora growth in saline-sodic soils in the Songnen Plain, northeast China. The experiment included five treatments in which the soil matric potential (SMP) at 0.2 m depth was controlled at -5, -10, -15, -20 and -25 kPa after the P. tenuiflora germinated. Consequently, the total water applied increased with increased matric potential. The results showed that Drip Irrigation influenced the water content, electrical conductivity of saturated-soil extract (ECe) and pH distributions, and inhibited the buildup of salts in the root zone, which enabled seeds to germinate and emerge. The ECe and pH in the whole soil profiles decreased as the SMP increased. After two years of the experiment, the tiller numbers, height, spike number and length, aboveground biomass and coverage of P. tenuiflora all increased greatly; and the growth of -15 and -20 kPa treatments were better than other treatments. Taken together, these results indicate that Drip Irrigation can be used to provide suitable conditions for the germination of P. tenuiflora seeds in the Songnen Plain and induce good growth, and the SMP of -15 and -20 kPa at a depth of 0.2 m immediately under a Drip emitter can be used as an indicator for saline-sodic P. tenuiflora grassland restoration in Songnen Plain. The results provide theoretical and technological guidance for reclamation and use of salt-affected soil, as well as for easy and quick restoration and reconstruction of saline-sodic grasslands. (C) 2012 Elsevier B.V. All rights reserved.
Bo Zhou - One of the best experts on this subject based on the ideXlab platform.
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mechanism of intermittent fluctuated water pressure on emitter clogging substances formation in Drip Irrigation system utilizing high sediment water
Agricultural Water Management, 2019Co-Authors: Peng Song, Bo Zhou, Yang Xiao, Tahir Muhammad, Zeyuan Liu, Hongxu ZhouAbstract:Abstract Emitter clogging is one of the bottlenecks that restricts the application and promotion of Drip Irrigation technology. Applying intermittent fluctuated water pressure is regarded as an effective way to overcome Drip Irrigation emitter clogging when using high sediment water. Therefore, a Drip Irrigation experiment using Yellow River water was carried out at Deng Kou County, Inner Mongolia, China, to study emitter clogging controlling effects of three fluctuation patterns. The control group (CG) operation pressure was 40 kPa, and three intermittent fluctuated water pressure modes were 40 kPa + fluctuating water pressure for 1 h (FP1 h), 2 h (FP2 h), and 4 h (FP4 h), respectively. The system was fluctuated once every 16 h, and the amplitude of the fluctuating water pressure was 80–100 kPa with a cycle of 40 s. The characteristics of the sediment size and mineral components of clogging substances found in emitters and laterals were also analyzed. The results showed that intermittent fluctuated water pressure not only directly changed the flow velocity distribution in the emitter flow path to reduce the deposition of clogging substances, but also controlled the formation of clogging substances inside the laterals to avoid enhanced emitter clogging by transporting into the emitter. The intermittent fluctuated operating pressure could effectively reduce contents of emitter clogging substance in Drip Irrigation, and the longer period it was applied, the better controlling effect was observed. Comparing with the CG, applying intermittent fluctuated water pressure with constant period of 4 h would reduce the total clogging substance contents by 26%. The clay and powder particles were reduced by 56% and 34%, respectively. Meanwhile the quartz, silicate, calcium magnesium and carbonate in the clogging substances decreased by 36%, 35%, and 11%, respectively. Thus, the discharge ratio variation coefficient (Dra) and Christiansen Uniformity coefficient (CU) increased by 10.1–16.7% and 8.9–14.2%, correspondingly. These results could provide references for the application and promotion of Drip Irrigation technology using water with high sediment load.
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effects of microbial community variation on bio clogging in Drip Irrigation emitters using reclaimed water
Agricultural Water Management, 2017Co-Authors: Bo Zhou, Tianzhi Wang, Vincent F BraltsAbstract:Abstract Drip Irrigation emitter clogging is one of the key barriers to the development and application of reclaimed water Drip Irrigation technology. Reclaimed water typically contains large amounts of bacteria, and their excretions, the sticky extracellular polymeric substances (EPS). Indeed, different amounts and types of microorganisms affect Drip Irrigation emitter clogging, especially bio-clogging process, via excretive EPS. Therefore, it is important to study the dynamic microbial community structure and its effect on the emitter bio-clogging process. In this paper, a Drip Irrigation experiment using reclaimed water was carried out. Phospholipid fatty acids (PLFAs) in biofilm (bio-clogging substance) were taken as the biomarker of microbial community inside emitters, and the dynamic variation of microbial community in Drip Irrigation emitter and its effect on the clogging process were studied. The results showed that the microbial growth of biofilms inside 9 types of Drip Irrigation emitters could enhance emitter clogging, and the PLFAs showed S-shaped pattern with emitter clogging degrees (R2 > 0.95, p
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eight emitters clogging characteristics and its suitability under on site reclaimed water Drip Irrigation
Irrigation Science, 2014Co-Authors: Yiting Pei, Bo Zhou, Yaoze Liu, Ze Shi, Yinguang JiangAbstract:Drip Irrigation is the most effective and reliable method for reclaimed water Irrigation. The water usually contains a lot of suspended particles, metal salt ions, organisms and microbial communities, which will enhance the possibility of emitter clogging or more complex clogging mechanism. Emitter clogging has become one of the key problems to the application and popularization of the Drip Irrigation technology. In this paper, we selected four kinds of pressure-compensating emitters and four kinds of non-pressure-compensating emitters, and executed the experiment of Drip Irrigation with on-site reclaimed water treated with cyclic activated sludge system (CASS). The emitter discharge ratio variation (Dra), coefficient of uniformity (CU) and clogging rate distribution were analyzed to evaluate the emitter clogging characteristics after eliminating the effect of temperature and pressure on the emitter outflow by data correction. The results showed that Dra and CU varied in three periods as system operation. The beginning of experiment was the fluctuated balance period, Dra and CU recurrent fluctuated in 5 %, and the emitters clogged at some spots after the system run 36–48 h. Then the two parameters varied linearly in 60–108 h, tuning into the initiate linear period, as the non-pressure-compensating emitters got an obvious linear change than the pressure-compensating ones with the gradient changed from −0.094 to 0.042 and −0.073 to 0.047, respectively. Some of the emitters have a significant difference on these two parameters at this stage. After the restarting in the second year, Dra and CU decreased sharply. The maximum decrement was, respectively, 9.6 and 10.7 %. Then they varied in line with a greater slope degree as all emitters reached the significant level, the gradient ranges were −0.176 to 0.115 and −0.216 to 0.117, respectively. This stage was called the accelerated linear period. Seriously clogged and completely clogged emitters appeared, and both Dra and CU dropped down to 38.7 and 41.5 %. Various degrees of clogged emitters often emerged in the end part of lateral at first then propelled to the head gradually, the completely clogged emitters in the end accounted for more than 73.0 % when the system run 540 h. Comprehensively considered, the pressure-compensating emitters and cusp-shaped saw-tooth non-pressure-compensating emitters with short flow path are recommended in reclaimed water Drip Irrigation. These researches are aimed to provide references explaining the emitter clogging mechanism of reclaimed water Drip Irrigation as well as its technological application and popularization.
Ruoshui Wang - One of the best experts on this subject based on the ideXlab platform.
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assessment of soil enzyme activities of saline sodic soil under Drip Irrigation in the songnen plain
Paddy and Water Environment, 2013Co-Authors: Yaohu Kang, Shuqin Wan, Shuhui Liu, Ruoshui WangAbstract:A field experiment was carried out to research the changes and spatial distributions of soil enzyme activities in saline-sodic soil for a different number of cultivated years under Drip Irrigation. The distributions of alkaline phosphatase, urease, and sucrase activities within 40 cm in both horizontal and vertical directions of the emitter in saline-sodic soils planted with Leymus chinensis for 1st, 2nd, and 3rd year were studied. A mathematical method was used to determine the relationships between soil enzyme activities and soil environmental factors contain the electrical conductivity of saturated-soil extract, pH value, available nutrient, and organic carbon. Alkaline phosphatase, urease, and sucrase activities all increased with cultivated years in saline-sodic soil under Drip Irrigation: from 4.5, 1.39 and 19.39 to 20.25, 3.17, and 61.33 mu g g(-1) h(-1), respectively, after planting L. chinensis for 3 year. Alkaline phosphatase, urease, and sucrase activities all decreased with increased horizontal and vertical distance from the emitter. After 3 year of Drip Irrigation, the correlations between soil enzyme activities and soil environment factors had stronger correlations than in the unreclaimed land. After 4-6 years, the soil enzyme activities should attain the level of the natural L. chinensis grassland.
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germination and growth of puccinellia tenuiflora in saline sodic soil under Drip Irrigation
Agricultural Water Management, 2012Co-Authors: Shuhui Liu, Yaohu Kang, Shuqin Wan, Shufang Jiang, Zhichun Wang, Zhengwei Liang, Ruoshui WangAbstract:Field experiments were conducted to investigate the effects of Drip Irrigation on seed germination and Puccinellia tenuiflora growth in saline-sodic soils in the Songnen Plain, northeast China. The experiment included five treatments in which the soil matric potential (SMP) at 0.2 m depth was controlled at -5, -10, -15, -20 and -25 kPa after the P. tenuiflora germinated. Consequently, the total water applied increased with increased matric potential. The results showed that Drip Irrigation influenced the water content, electrical conductivity of saturated-soil extract (ECe) and pH distributions, and inhibited the buildup of salts in the root zone, which enabled seeds to germinate and emerge. The ECe and pH in the whole soil profiles decreased as the SMP increased. After two years of the experiment, the tiller numbers, height, spike number and length, aboveground biomass and coverage of P. tenuiflora all increased greatly; and the growth of -15 and -20 kPa treatments were better than other treatments. Taken together, these results indicate that Drip Irrigation can be used to provide suitable conditions for the germination of P. tenuiflora seeds in the Songnen Plain and induce good growth, and the SMP of -15 and -20 kPa at a depth of 0.2 m immediately under a Drip emitter can be used as an indicator for saline-sodic P. tenuiflora grassland restoration in Songnen Plain. The results provide theoretical and technological guidance for reclamation and use of salt-affected soil, as well as for easy and quick restoration and reconstruction of saline-sodic grasslands. (C) 2012 Elsevier B.V. All rights reserved.
Donald M. May - One of the best experts on this subject based on the ideXlab platform.
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Drip Irrigation of tomato and cotton under shallow saline ground water conditions
Irrigation and Drainage Systems, 2006Co-Authors: Blaine R Hanson, Robert B Hutmacher, Donald M. MayAbstract:Artificial subsurface drainage is not an option for addressing the saline, shallow ground water conditions along the west side of the San Joaquin Valley because of the lack of drainage water disposal facilities. Thus, the salinity/drainage problem of the valley must be addressed through improved Irrigation practices. One option is to use Drip Irrigation in the salt affected soil.
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Effect of subsurface Drip Irrigation on processing tomato yield, water table depth, soil salinity, and profitability
Agricultural Water Management, 2004Co-Authors: Blaine R Hanson, Donald M. MayAbstract:Abstract The potential of subsurface Drip Irrigation of processing tomatoes to reduce subsurface drainage, control soil salinity, and increase farm profits in areas affected by saline, shallow ground water was evaluated at three fields with fine-textured, salt-affected soil along the west side of the San Joaquin Valley of California. No subsurface drainage systems were installed in these fields. Yield and quality of tomato of the Drip systems were compared with sprinkler Irrigation. Yield increases of 12.90–22.62 Mg/ha were found for the Drip systems compared to the sprinkler systems with similar amounts of applied water. Soluble solids of the Drip-irrigated tomatoes were acceptable. Response of water table levels during Drip Irrigation showed that properly managed Drip systems could reduce percolation below the root zone. Yields of the Drip systems were similar over the range of soil salinity levels that occurred near the Drip lines. Profits under Drip Irrigation were 867 to $ 1493 ha−1 more compared to sprinkler Irrigation, depending on the amount of yield increase and the interest rate used in the economic analysis.
A M Elghamry - One of the best experts on this subject based on the ideXlab platform.
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evaluation of humic substances fertigation through surface and subsurface Drip Irrigation systems on potato grown under egyptian sandy soil conditions
Agricultural Water Management, 2009Co-Authors: E M Selim, Ahmed Mosa, A M ElghamryAbstract:The aim of this study was to evaluate the effect of humic substances application in sandy soil under surface and subsurface Drip Irrigation systems on potato tubers yield quantity, quality, nutrients concentration in tubers and soil fertility after harvesting. For this purpose, field experiment was carried out at the experimental farm of the Agricultural Research Station, National Research Center, El-Nubaria district, Egypt during the winter season of 2007/2008. The used experimental design was split plot design with three replicates, main treatments were presented Irrigation systems, i.e. surface and subsurface Drip Irrigation, while subtreatments were presented rates of humic substances additives which were 0, 60 and 120kgha-1. Results showed that increasing humic substances application rates up to 120kgha-1 enhanced tubers yield quantity, starch content and total soluble solids. The increase of humic substances application rates was associated with the decrease of nutrients leaching, which was reflected on increasing macro- and micronutrients concentration in potato tubers, as well as increasing concentration of these nutrients in soil after tubers harvesting. Subsurface Drip Irrigation system was found to be more efficient than surface Drip Irrigation system on improving tubers yield quantity, quality parameters and nutrients concentration content, in addition to soil fertility after harvesting.
