نوع مقاله : مقاله پژوهشی
نویسندگان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
To study the crop coefficients of summer maize a lysimeter experiment was conducted under conditions that shallow and saline groundwater contributes to supply required water. Twenty-four lysimeters each with 1.2 m depth and 0.8 m diameter were installed. Thereafter, maize was planted in each lysimeter. The depth of groundwater table in the lysimeters was set to 0.6 m by using Marriotte Bottles. In this experiment, Three groundwater salinity levels (2.5, 5 and 7.5 dS/m) with two irrigation levels (at 70% and 100% rates of evaporation from pan class A before irrigation period) were used. Soil water was replenished on a weekly basis. Factorial experiment was established in a randomized complete block design with three replications. In an individual treatment, maize was planted with full irrigation on one hand and no ground water (NGW) considered as the control treatment on the other hand and they both were replicated three times. In this study, the equation of actual crop coefficient Kca, and its components including Kci (the coefficient related to irrigation) and Kcg (the coefficient related to groundwater), was obtained based on the water balance equation. Then regression analyses were used to develop the Kci, Kcg and Kca crop coefficient curves for each salinity and irrigation treatments. The results indicated that the percent of groundwater contribution at full irrigation level were 5.28, 4.61 and 3.76 for each of.
کلیدواژهها [English]
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