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Moazzam Hassanpour Asil; Jamalali Olfati; Mohammadreza Khaledian; Zahra-Sadat Nabavi Mohajer
Abstract
The purpose of the present study was to determine the effect of fertigation with different levels of nutrient solutions and different irrigation regimes on water productivity (ratio of yield to water containing nutrients) in greenhouse lily cultivation. The experiment was conducted in two years at the ...
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The purpose of the present study was to determine the effect of fertigation with different levels of nutrient solutions and different irrigation regimes on water productivity (ratio of yield to water containing nutrients) in greenhouse lily cultivation. The experiment was conducted in two years at the University of Guilan. In the first year, the best treatment was determined among four different concentrations of nutrient solution according to Coic solution including S1, S2, S3, and S4. The results of mean comparison showed that S1 treatment (treatment with the highest concentration of nutrients) had a positive effect on most vegetative, reproductive, and postharvest characteristics of lily. In the second year, with appropriate nutrient solution and three different levels including S11, S12, and S13, different irrigation regimes according to field capacity percent (%FC) were considered. Four different irrigation regimes including 70%, 80%, 90%, and 100% FC were applied. The results of the second experiment showed that application of deficit irrigation treatments including 90%, 80%, and 70% of FC increased water productivity without any significant effects on the vegetative and reproductive characteristics. The results also showed that irrigation treatments had significant effects on traits such as vase life, which was increased by decreasing water consumption and increasing nutrient concentration. Regarding the vegetative characteristics of lily plants, the data showed that traits such as fresh and dry weights of roots, leaves, and flowers were positively affected by decreasing irrigation levels and increasing concentration of nutrient solution, while plant height and both number and weight of daughter bulbs were not affected by these treatments. The highest water productivity (nutrients solutions) was obtained in the S3 and 80% FC, being 21.57 kg/m3.
b k; f m; t s
Abstract
Drip irrigation has a priority in selecting an appropriate irrigation method in arid and semi-arid regions because of its potential of precisely applying water and chemicals both in quantity and position. Proper design and management of a drip fertigation system is, to some extent, dependent upon a better ...
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Drip irrigation has a priority in selecting an appropriate irrigation method in arid and semi-arid regions because of its potential of precisely applying water and chemicals both in quantity and position. Proper design and management of a drip fertigation system is, to some extent, dependent upon a better understanding of wetting patterns and water and solute distributions in soil under different combinations of soil type and layering, emitter application rate, volume applied and fertigation concentration. In this study, experiments were carried out in a transparent plexiglass tank (0.5 x1.22 x 3 m) using three different soil textures (light, heavy, and medium). The emitter outflows were considered 2.4, 4, and 6 lit/hr with irrigation duration of 6 hr. The fertigation treatments included treatments with nitrate concentrations of 125, 250, and 375 mg/L. Urea fertilizer (CH4N2O) (46% nitrogen) was used in the fertigation treatments. Then, using the p theorem of Buckingham and Dimension Analysis (DA), equations were developed to estimate the pattern of nitrate distribution pattern (horizontal and vertical) in the three soil textures. The equations developed were functions of initial soil nitrate content, nitrate concentrations in fertigation, initial moisture, radial distance of points, applied water volume, hydraulic conductivity, and emitter outflows. The results of the comparisons between simulated and observed values showed that the equations were capable of predicting the pattern of moisture distribution in different directions. The averages of Root Mean Square Error (RMSE) values in clay soil and for emitter outflows 2.4, 4, and 6 lit/hr were 0.025, 0.105 and 0.093, respectively. These values for loamy soil were 0.032, 0.052, and 0.05, respectively, and for sandy soil were 0.023, 0.038, and 0.035, respectively. Considering these equations in designing surface drip irrigation systems could improve system performance.