Pedotransfer Functions for Estimation of Soil Moisture Constants from Penetration Resistance Measurements and Some Soil Properties

Studies to prediction of soil moisture constants and other soil properties  rather than direct measurements were never dwindle importance.  Models were derived from other soil properties obtained easily.  Therefore, in this study focused on the predictability of some moisture  constants, whose determination was often difficult and time-consuming,  from penetration resistance measurements. In the improvement of  alternative models for the estimation of moisture constants; in addition  to penetration resistance, textural fractions insert ignore into journalissuearticles values(sand, clay and silt);, bulk  density, CaCO3 % and organic matter contents were included. The  models were created according to soil groups with different textures  insert ignore into journalissuearticles values(sandy, loamy, clay); for moisture constants at 0.1, 0.33, 0.5 and 15 bar.  In the models for estimation of 0.1, 0.33, 0.5 and 15 bar moisture  content, the highest differences in R2 values insert ignore into journalissuearticles values(0.61, 0.60, 0.64 and 0.59);  between the actual and the predicted data was obtained for loamy soils.  For this group, the root means square error insert ignore into journalissuearticles values(RMSE); ranged between  1.32 and 1.90 %, and in addition, the mean error insert ignore into journalissuearticles values(ME); was determined  to be in a range from 1.53 to 2.05 %. For the estimation of moisture  content at different soil moisture tensions using organic matter, bulk  density, clay and penetration resistance properties, the coefficient of  determination ranged from 71 to 77 %. Therefore, it is concluded that  the alternative models, developed using penetration resistance or by the  addition of some other soil properties, could be used safely in the loamy  texture soils.