جستجوی مقالات مرتبط با کلیدواژه "عمق آب آبیاری" در نشریات گروه "آب و خاک"

Potato is the fifth largest food source in the world, which is widely cultivated in Iran. Due to the sensitivity of this crop to the amount of irrigation water, it is necessary to investigate the effect of different amounts of irrigation on it. For this purpose, SWAP model was used as a powerful tool for potato simulation. At first, to evaluate this model, biennial data (1998-1999) collected from a research station in ChaharTakhteh, Shahrekord were used. These data include five levels of water stress (E0, E1, E2, E3 and E4, respectively, indicating 100, 85, 70, 50 and 30% water supply) and three stress application times (T1, T2, and T3 indicating 50, 100, and 150 days after sowing, respectively). NRMSE values for yield and water use efficiency showed that SWAP model in both calibration and validation were excellent (NRMSE < 0.1). The error of this model for simulating yield in the calibration and validation stages was equal to 1.42 ton.ha-1 (4.6 percent) and 2.36 ton.ha-1 (7.2 percent), respectively. The error value of this model for water consumption efficiency in the mentioned two stages was 0.04 kg.m-3 (4.9%) and 0.33 kg.m-3 (7.7%), respectively. The efficiency of the SWAP for potato simulation during calibration and validation was acceptable. Potato irrigation planning using SWAP showed that to achieve maximum yield, the irrigation water depth in the first growing period is equal to 750 mm and irrigation depths are 900 mm in subsequent periods.

Due to the water crisis in Iran¡ the application of a greenhouse cultivation of optimum use for the water resources is expanding. The main objective of this research is to determine the frequency and amount of proper irrigation water in the cultivation of greenhouse tomato (cv Falkato).For this reason¡ an experiment was performed in completely randomized block split plot experiment design at three replications. Irrigation frequency as main plot consists of daily¡ two and three days. The effect of irrigation interval on a constant basis daily¡ two or three days once were imposed and treatments of irrigation water levels in the first year¡ 75%ETc¡ 100%ETc and 125%ETc and in the second year 50%ETc¡ 75% ETc and 100%ETc were considered. Results showed that the effect of irrigation frequency and levels on tomato yield and some quantitative variables were not significant. Although the yields showed reduction with increasing irrigation frequency. The least average weight of a tomato belonged to three days frequency. The highest value of WUE in the first and second years was observed in 75% ETc and 50%ETc irrigation level. Differences between the water use efficiency in irrigation frequencies was not significant. The interaction between irrigation frequency and levels showed in the first year the highest yield occurred in 100% and 125% ETc irrigation levels and 2 days irrigation frequency and the least yield occurred in 2 days irrigation frequency and 100% ETc. Mean comparisons of interaction between irrigation frequency and levels showed the highest yield in the first year occurred in 100% and 125% ETc of irrigation levels and intervals 2 days and the least for 3 days and 100%. Also in second year¡ the highest yield related to 75% ETc irrigation level and 2 days irrigation frequency and the lowest were related to 2 days irrigation frequency and 50% ETc¡ respectively. According to the results¡ two or three day irrigation frequency can be used instead of daily irrigation. Leaching is needed when irrigated with 75% ETc irrigation level.