Determining the water requirement and Applied water of bell pepper in the greenhouse and comparing it with the results of the water requirement system

Document Type : Research Paper


1 *. PhD candidate, Department of Irrigation and Reclamation Engineering, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.

2 Assistant professor, Department of irrigation and soil physics, Soil and Water Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran

3 Associated professor of Department of Irrigation and soil physics, Soil and Water Research Institute, Agricultural Research Education and Extension Organization (AREEO), Karaj, Iran.


pepper is one of the most important greenhouse crops worldwide and has an important economic value. Surveys show that four percent of the cultivated area of greenhouse crops is dedicated to pepper and this amount is increasing. One of the important goals of developing greenhouses is to improve production efficiency and increase water and fertilizer efficiency. This research was carried out to provide irrigation and fert fertigation scheduling for greenhouse peppers through monitoring soil moisture and salinity in the root zone in 1400. The treatments include three irrigation treatments I1, I2 and I3 (100, 80 and 60% of the plant's water requirement) and three fertigation treatments F1, F2 and F3 (150, 100 and 50% of the plant's fertilizer requirement) in three replications. The total irrigation measured for treatments I1, I2 and I3 was 397, 318 and 238 mm, respectively. The irrigation requirement values simulated by the irrigation requirement system of agricultural and garden plants were compared with the measured values, and the statistical indices RMSE, NRMSE, MBE, d and EF were obtained equal to 38.55, 0.21, and -21.1, 0.99 and 0.95 respectively. The results showed that the effect of irrigation, fertigation and their mutual effect on the yield of greenhouse pepper was significant. The maximum yield of pepper in the I1F1 treatment was 114.38 tons/ha and the minimum in the I3F1 treatment was 40.96 tons/ha. Also, the maximum water productivity in the I2F2 treatment was 31.05 kg/m3 and the minimum in the I3F1 treatment was 17.19 kg/m3. Although the best performance was obtained in the I1F1 treatment, the best water efficiency was obtained in the I2F2 treatment, and the product yield was not significantly different in these two treatments. In general, 20% deficit irrigation is recommended by monitoring the moisture of the root zone in greenhouse pepper production.


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