Masoud Mohammadi; Hossin Molavi; Abdolmajid Liaghat; Masoud Parsinejad
Abstract
Salinity and water stress are the main problems of agricultural production in many parts of the world, especially in arid and semi-arid areas. Therefore, this study was conducted to investigate the effects of Zeolite application under salinity and ...
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Salinity and water stress are the main problems of agricultural production in many parts of the world, especially in arid and semi-arid areas. Therefore, this study was conducted to investigate the effects of Zeolite application under salinity and water stress conditions on yield and yield components of Corn in Karaj, Iran. A factorial design with randomized complete block arrangement was used with three replications including three factors: salinity, irrigation water, and Zeolite application. Irrigation water, salinity and Zeolite application factors consisted of two levels each:W1=100% and W2=50% of crop water requirement; S1=0.7, S2=5 dS/m, and Z1=0 and Z2=10 t/ha, respectively. The soil texture was clay loam. Results showed that salinity and water stresses reduced yield and yield components, while Zeolite application increased them. Simultaneous impact of salinity, deficit irrigation, and Zeolite application had significant effect on corn yield, the 1000 kernels weight, number of grains per ear, and plant height. The maximum corn yield, 1000 seeds weight, number of grains per ear, and plant height were, respectively, 7233.3 kg/ha, 309 g, 504, and 220.7 cm and corresponded to W1S1Z2 treatment, while the minimum corn yield, 1000 seeds weight, number of grains per ear and plant height were 2296 kg/ha, 101.7 g, 159, and 146.3 cm, respectively, and belonged to W2S2Z1 treatment. The maximum water use efficiency (1.41 kg/m3) and its minimum (0.68 kg/m3) were observed in W2S1Z2 and W1S2Z1 treatments, respectively.
h ramezani; a liaghat; m parsinejad; m ramezani
Abstract
Agricultural drought occurs when soil moisture is less than that required for the optimized production and damages crop yield. Drought indexes are used for monitoring purposes and in some of these indicators rainfall data are used. But, agricultural droughts indexes use soil moisture data. ...
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Agricultural drought occurs when soil moisture is less than that required for the optimized production and damages crop yield. Drought indexes are used for monitoring purposes and in some of these indicators rainfall data are used. But, agricultural droughts indexes use soil moisture data. Among the most important drought indexes that use soil moisture as input parameter, soil moisture drought index (SMDI) can be noted. Generally, mathematical models are used for soil moisture estimation. The objective of this study was to estimate soil moisture using AquaCrop model and to calculate SMDI with this estimation and compare it with the rainfall-based drought indexes such as PNI, DI, SPI and CZI, using Qazvin synoptic station data of 1982-2008. The results of soil moisture estimation using AquaCrop showed that monthly changes in soil moisture at 5 cm depth were very strong. With increasing depth, soil moisture changes were less and remained constant after 40 cm of depth. Average values of SMDI, PNI, DI, SPI and CZI were, respectively, 0.41.2, 10026.2, 0.042.6, 0.01.0, and 0.01.0. Based on SMDI, the wettest year was 1994 while the driest years were 1997, 1999 and 2008. But, based on other indexes, the wettest and driest years were 1982 and 2008. The main point for SMDI is that, in addition to the current season soil moisture conditions, the index uses soil moisture conditions of the previous year to calculate SMDI. According to our results, SMDI had low coefficient of determination with the other drought indexes, rain, and evaporation.