No abstract

Increasing water use efficiency (WUE) is a fundamental remedy for food production under conditions of water scarcity. The aim of this study was to evaluate the potential for water saving and yield improvements with use of the ET-HS model and subsurface drip irrigation. For this purpose, four irrigation treatments were installed in a silty loam soil at an experimental farm near the city of Isfahan in Iran in 2000 and 2001. The treatments included: surface drip irrigation (DI), subsurface drip irrigation at 15 cm depth (SDI 15 ), subsurface drip irrigation at 30 cm depth (SDI 30 ), and furrow irrigation (FI). These treatments were repeated for two genera of potato, Marfona and Navita (traditional genus of potato in Isfahan region), tomato and eggplant. In this research, a completely randomized block design with three replications was applied to each crop. Also, in all of these treatments, crop water requirement and irrigation schedules were determined by the ET-HS model. For this purpose, maximum and minimum temperature were measured daily and filled in the model. Based on the results, SDI 15 has the most efficient use of water in production and is substantially different from other treatments, which measured 7.84, 3.84, 13.15 and 11.64 kg m À3 in Marfona, Navita, tomato and eggplant, respectively. The results show that the maximum crop yield occurred in SDI 15 in Marfona, Navita and eggplant and in DI and SDI 15 in tomato. A part of this increase in yield in SDI 15 related to better soil moisture in the root zone, less water runoff, and less surface evaporation. Additionally, the results show considerable reduction of surface evaporation in SDI treatments. Finally, it can be concluded that subsurface drip irrigation, with drippers installed at a depth of 15 cm, and implementation of the ET-HS model for estimating irrigation scheduling, is the best irrigation method for Marfona, Navita, tomato and eggplant. Copyright aubergines, avec trois réplications en blocs totalement aléatoires pour chaque culture. En outre, pour chacun de ces traitements, les besoins en eau des plantes et la programmation de l'irrigation étaient déterminés par le modèle ET-HS. À cette fin, les températures maximales et minimales étaient mesurées quotidiennement et entrées dans le modèle. L'analyse des résultats montre que la technique SDI15 permet la meilleure utilité de l'eau et fournit des rendements significativement différents des autres techniques (respectivement 7,84, 3,84, 13,15 et 11,64 kg m À3 pour Marfona, Navita, tomate et aubergine). Les résultats montrent que le rendement maximum a été obtenu avec SDI15 pour Marfona, Navita et l'aubergine, et avec DI et SDI15 pour la tomate. Une partie de ce supplément de rendement avec SDI15 était liée à une meilleure humidité du sol dans la zone racinaire, un moindre ruissellement, et une moindre évaporation de surface. De plus, les résultats montrent une réduction considérable de l'évaporation de surface avec la technique SDI. En conclusion, l'irrigation au goutte-à-goutte souterr...

Qualitative and quantitative restrictions on water resources have given rise to large water stress on land and plants. The recognition of such stresses can be of help in crop management. Due to the large impact on yield, water stress plays an important role in planning proper irrigation, timing, and amount of water needed by plants. Crop Water Stress Index (CWSI) is used for monitoring and quantifying water stress as well as for irrigation scheduling. This study was conducted for the purpose of determining the Maize (SC-701) irrigation Scheduling, use of leaf temperature in the north of Isfahan, Iran, in the crop year 2013, with five irrigation areas, where the amount of Total Available Water (TAW) was 35, 65, 75, 85, 100% respectively, in four replications. Results revealed that in return of TAW from 35 to 100%, Leaf and air temperature difference (Tl-Ta) reached 4 °C. CWSI rose about three times. CWSI in the day before the irrigation in treatment T1 and T5 was about 0.12 and 0.46, respectively. The results revealed that non-stress equation for corn in the T3 (75%TAW), was 7105 .and stress equation was completely fixed and is equal to 2.3. CWSI index is based on irrigation planning and it was 0.24. Examining yield results revealed that irrigation scheduling in this area should be done by treatment at 75% TAW.

No abstract

Trace element contamination in aquatic ecosystems is one of the most important concerning of environmental health.Submerged aquatic plants can be used for the removal of Trace elements. The aim of this study was to investigate how Ceratophyllum demersum could affect on wastewater quality for recycling the wastewater to reuse for other purposes in agriculture and industrial fields. In this survey, two treatments in four replications were designed. The treatments were included raw municipal wastewater (RMW) and treated municipal wastewater (TMW). The experiment performed in outdoor of Khorasgan University area without aeration through 18 days period. In this study Fe, Zn, Mn, Ni, Pb and Cd were measured in wastewater through experiment. The average of removal efficiency of Fe, Zn, Mn, Ni, Pb and Cd from TMW were 40%, 47.5%, 90.82%, 96.55%, 100% and 100% respectively. Removal efficiency of Fe, Zn, Mn, Ni, Pb and Cd from RMW were 67.5%, 37.5%, 94.21%, 94.21%, 100% and 97.77% respectively. The results indicated that Ceratophyllum demersum had high capabilities to remove trace elements directly from the contaminated water. Therefore it can conclude that Ceratophyllum demersum could be used for refining the wastewater. @JASEM