%0 Journal Article %T A model to estimate soil water depletion coefficient using plant and soil properties %J Iranian Journal of Soil and Water Research %I University of Tehran %Z 2008-479X %A Meskini Vishkaei, Fatmeh %A Mohammadi, Mohammad Hosein %A Neishabouri, Mohammad Reza %A Shekari, Farid %D 2017 %\ 11/22/2017 %V 48 %N 4 %P 749-758 %! A model to estimate soil water depletion coefficient using plant and soil properties %K Soil available water %K Plant response factor %K Soil critical moisture %K Canola %K Wheat %R 10.22059/ijswr.2017.212087.667505 %X IIn current study, a conceptual mathematic model is developed to determine the relationship between plant response factor to water (ky) and soil critical moisture (c) that below c, plant is under stress. The evaluation of model performance was done using a set of experimental data from a green-house trial. The results showed that for a given Ky, relative plant yield (Yr) is linearly reduced by decreasing the differences soil moisture from c (c-). The greater sensitivity of plant type or growth stage to water deficit (higher Ky values) caused more slope of linear relationship between Yr and (c-). In the other words, it can be assigned more allowable depletion coefficient for the plants with low Ky values. Moreover, for a given Yr, plant sensitivity is exponentially increased by the reduction of soil moisture. In addition to confirm the model results, exprimental observations showed that the critical moisture of clay loam soil for both soil was 0.28 cm3 cm-3, while the c values of sandy loam soil for wheat and canola ware 0.21 and 0.195 cm3 cm-3, respectively. Soil allowable depletion coefficient for wheat in both soils was obtained about 0.35. Whereas, soil allowable depletion coefficient for canola in sandy loam soil (F=0.44) was more than clay loam soil (F=0.38). %U https://ijswr.ut.ac.ir/article_64148_16d3baa1c238e374107d7a65274c8deb.pdf