Submitted to: Abstract of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: September 1, 2000
Publication Date: August 5, 2000
Technical Abstract: The MUUF software was developed to use soil series name and textural class of the uppermost soil horizon to estimate soil water retention. The MUUF contains pedotransfer functions (PTFs) that use the clay activity ratio to characterize effects of soil mineralogy on hydraulic properties. Our objectives were (a) to test the MUUF with data for Southern Plains, and (b) )to see whether the MUUF PTF's will be more accurate with actual soil texture data as compared with the texture data from the series representative pedon. The root-mean-square error (RMSE) of water contents at 33 kPa in the uppermost horizon was about 0.04 when only textural class and soil names were used. Using actual texture did not change the accuracy. In deeper horizons, the RMSE was about 0.065 when only soil names and textural classes were used; the accuracy improved significantly as the actual texture was used. Using actual texture halved the RMSE of water content estimates at 1500 kPa. As compared with PTF's found in literature, the MUUF software provides an average or better accuracy of water retention estimates in the uppermost soil horizons from the soil series name and textural class. The MUUF PTF's are capable of the same degree of accuracy for deep soil horizons provided the actual texture data are available.