Correlation of students’ estimation and laboratory determination of soil texture

Soil texture helps understand physical and chemical properties of soils. Soil texture can be determined accurately in the laboratory, or it can be estimated through finger test in the field, the accuracy of the latter depends on the skills and experience of the person. However, such estimates provide quick results compared to laboratory measurement, which takes ample amount of time for final results. In an attempt to correlate field and laboratory soil texture results, 11 students were trained to develop their skills to determine field soil texture (finger test) and in determining soil texture in the laboratory using standard hydrometer method. When the finger test results were compared with the laboratory results, the students’ estimates predicted the actual clay and sand percentages with high degree of accuracy. The results showed a high variation between student’s and laboratory determination of soil texture. Estimation of sand fraction is slightly more difficult than clay particles. This study suggests that students require more practice to be able to estimate soil textural class accurately. It is recommended that students should use reference samples (known texture) to improve their skills.