In order to evaluate the effect of deficit irrigation at various growth stages on wheat growth and yield, a field experiment was conducted in the 2008-2009 growing season based on the completely randomized block with ...In order to evaluate the effect of deficit irrigation at various growth stages on wheat growth and yield, a field experiment was conducted in the 2008-2009 growing season based on the completely randomized block with four replications at the experimental farm of the College of Agriculture, Shiraz University, Shiraz, Iran, located at Badjgah. Treatments involved 13 irrigation regimes which applied in stem elongation, heading and grain filling growth stages. The highest seed yield （4,333 kg-ha-1） and the lowest ones （1,377 kg＇hal） were obtained from T1 （100% field capacity （FC） in all growth stages） and T13 （50% FC in all growth stages）, respectively. With limitation in water amount seed yield was diminished, but this trend was not significant at T4 （100%, 100% and 50% FC） and TI 1 （100%, 100% and 75~/0 FC）. Stepwise regression results revealed that, seed number per spike had the largest contribution （partial R2 = 0.72） in seed yield variation. Also at TI, T4, and TI 1 treatments （well water treatments） as well as TI3 （sever stress） head number m2 contribute most in seed yield determination （partial R2 = 0.96）. It can be concluded that water shortage during the grain filling period and its allocation to the other consecutive crop, can increase crop production in southern regions of Iran.展开更多
Irrigation advances in precision irrigation （PI） or site specific irrigation （SSI） have been considerable in research; however, commercialization lags. SSI/PI has applications when soil texture variability affects...Irrigation advances in precision irrigation （PI） or site specific irrigation （SSI） have been considerable in research; however, commercialization lags. SSI/PI has applications when soil texture variability affects soil water holding capacity or when crop yield or biotic stresses （insects or diseases） are spatially variable. SSI/PI uses variable rate application technologies, mainly with center-pivots or lateral-move or linear irrigation machines, to match crop needs or soil water holding constraints. Variable rate applications are achieved by variable nozzle flow rates, pulsing nozzle flows, or multiple nozzles on separate submains. Newer center pivot and linear machines are controlled by on-board microprocessor systems that can be integrated with supervisory control and data acquisition controllers for both communication and control of the variable rate application for specific sets of nozzles or individual nozzles for management zones. Communication for center pivot or linear controllers typically uses radio telemetry, wireless interact links, or cellular telephones. Precision irrigation has limited utility without precise irrigation scheduling （temporally and spatially）. Plant or soil sensors are used to initiate or complete an irrigation event. Automated weather stations provide site information for determining the irrigation requirement using crop models or simpler reference evapotranspiration （ET）, data to be used with crop coefficients. Remote sensing is being used to measure crop water status or crop development from spectral reflectance. Near-surface remote sensing with sensors mounted on moving irrigation systems provide critical spatial integration from point weather networks and feedback on crop ET and irrigation controls in advanced automated systems for SSI/PI.展开更多
The Tunisian oases face serious problems of waterlogging and salinization caused by mismanagement of water and soil resources and the reduced discharge of drainage water. The oases space is based on a fragile balance ...The Tunisian oases face serious problems of waterlogging and salinization caused by mismanagement of water and soil resources and the reduced discharge of drainage water. The oases space is based on a fragile balance between water, soil and man, which is now changed by modem irrigation and drainage systems. The oases pump most of their water from deep aquifers and only to a small degree from shallow aquifers. The quality of the irrigation water and the presence of a shallow saline water table are the main causes of salinization of the oases. Concerning the salt-affected landscapes and hydro-saline dynamic, the authors distinguish an equilibrium dynamic of salts to the parcel which depends on water management, and an equilibrium dynamic at the level of the basin watershed which is powered by drilling and ending in hypersaline depressions. For the management of salinization and waterlogging, a combination of agricultural management techniques are used, the first being modem methods of irrigation and drainage. Other, less used methods are sandy amendment, the reuse of drainage waters, geothermal waters and of treated wastewater.展开更多
he effects of greywater irrigation on four commonly used agricultural soils and models were studied. Sand, sandy loam, sandy clay and light clay soils were selected as common Iraq soils. Soil＇s chemical and physical ...he effects of greywater irrigation on four commonly used agricultural soils and models were studied. Sand, sandy loam, sandy clay and light clay soils were selected as common Iraq soils. Soil＇s chemical and physical properties under different irrigation regimes were daily measured during period extended from February 2011 to April 2012 in Baghdad city and plant growth was monitored. A lab scale models of four acrylic columns of 100 mm diameter and 750 mm height were designed and constructed in environmental hydraulic lab at Mustansiriya University and tests were run concurrently with the characterization study to assess the effect of soil depth and loading rate on treatment efficiency. Soil samples were carried out in a site that had been drained with greywater for over 14 months. Measurements of greywater and treated greywater had been achieved which contains BODs, COD, pH, EC, TDS, turbidity, CI＋1, 504＋2, NO3＋1, Na＋l, Ca＋2, Mg＋2, E coli and coliform.展开更多
文摘In order to evaluate the effect of deficit irrigation at various growth stages on wheat growth and yield, a field experiment was conducted in the 2008-2009 growing season based on the completely randomized block with four replications at the experimental farm of the College of Agriculture, Shiraz University, Shiraz, Iran, located at Badjgah. Treatments involved 13 irrigation regimes which applied in stem elongation, heading and grain filling growth stages. The highest seed yield （4,333 kg-ha-1） and the lowest ones （1,377 kg＇hal） were obtained from T1 （100% field capacity （FC） in all growth stages） and T13 （50% FC in all growth stages）, respectively. With limitation in water amount seed yield was diminished, but this trend was not significant at T4 （100%, 100% and 50% FC） and TI 1 （100%, 100% and 75~/0 FC）. Stepwise regression results revealed that, seed number per spike had the largest contribution （partial R2 = 0.72） in seed yield variation. Also at TI, T4, and TI 1 treatments （well water treatments） as well as TI3 （sever stress） head number m2 contribute most in seed yield determination （partial R2 = 0.96）. It can be concluded that water shortage during the grain filling period and its allocation to the other consecutive crop, can increase crop production in southern regions of Iran.
文摘Irrigation advances in precision irrigation （PI） or site specific irrigation （SSI） have been considerable in research; however, commercialization lags. SSI/PI has applications when soil texture variability affects soil water holding capacity or when crop yield or biotic stresses （insects or diseases） are spatially variable. SSI/PI uses variable rate application technologies, mainly with center-pivots or lateral-move or linear irrigation machines, to match crop needs or soil water holding constraints. Variable rate applications are achieved by variable nozzle flow rates, pulsing nozzle flows, or multiple nozzles on separate submains. Newer center pivot and linear machines are controlled by on-board microprocessor systems that can be integrated with supervisory control and data acquisition controllers for both communication and control of the variable rate application for specific sets of nozzles or individual nozzles for management zones. Communication for center pivot or linear controllers typically uses radio telemetry, wireless interact links, or cellular telephones. Precision irrigation has limited utility without precise irrigation scheduling （temporally and spatially）. Plant or soil sensors are used to initiate or complete an irrigation event. Automated weather stations provide site information for determining the irrigation requirement using crop models or simpler reference evapotranspiration （ET）, data to be used with crop coefficients. Remote sensing is being used to measure crop water status or crop development from spectral reflectance. Near-surface remote sensing with sensors mounted on moving irrigation systems provide critical spatial integration from point weather networks and feedback on crop ET and irrigation controls in advanced automated systems for SSI/PI.
文摘The Tunisian oases face serious problems of waterlogging and salinization caused by mismanagement of water and soil resources and the reduced discharge of drainage water. The oases space is based on a fragile balance between water, soil and man, which is now changed by modem irrigation and drainage systems. The oases pump most of their water from deep aquifers and only to a small degree from shallow aquifers. The quality of the irrigation water and the presence of a shallow saline water table are the main causes of salinization of the oases. Concerning the salt-affected landscapes and hydro-saline dynamic, the authors distinguish an equilibrium dynamic of salts to the parcel which depends on water management, and an equilibrium dynamic at the level of the basin watershed which is powered by drilling and ending in hypersaline depressions. For the management of salinization and waterlogging, a combination of agricultural management techniques are used, the first being modem methods of irrigation and drainage. Other, less used methods are sandy amendment, the reuse of drainage waters, geothermal waters and of treated wastewater.
文摘he effects of greywater irrigation on four commonly used agricultural soils and models were studied. Sand, sandy loam, sandy clay and light clay soils were selected as common Iraq soils. Soil＇s chemical and physical properties under different irrigation regimes were daily measured during period extended from February 2011 to April 2012 in Baghdad city and plant growth was monitored. A lab scale models of four acrylic columns of 100 mm diameter and 750 mm height were designed and constructed in environmental hydraulic lab at Mustansiriya University and tests were run concurrently with the characterization study to assess the effect of soil depth and loading rate on treatment efficiency. Soil samples were carried out in a site that had been drained with greywater for over 14 months. Measurements of greywater and treated greywater had been achieved which contains BODs, COD, pH, EC, TDS, turbidity, CI＋1, 504＋2, NO3＋1, Na＋l, Ca＋2, Mg＋2, E coli and coliform.
