A More Simplified Hydrometer Method for Soil Texture Analysis

토성 판정을 위한 비중계방법 개선연구

This study was carried out to develop a more convenient way to analyze soil texture by hydrometer. Standard Hydrometer Method(SM), in which at least 7 times of reading is required for soil texture analysis, was compared with two other methods named as Soil Clay Fraction Procedure(SCFP) and Simplified for Soil Texture Analysis(SSTA), in which 2 or 3 times of hydrometer reading may be enough for soil texture analysis, respectively. There appeared to be very close correlation(nearly 1.0) between clay contents measured by the above three methods. The clay content measured by SCFP were overestimated by 0~2 percent than those by SM. Textural classes of 28 soil samples determined by SSTA were identical to those by SM. But, textural classes determined by SCFP appeared to be different from those by SM in 4 of 28 soil samples. Because the measurements of particle size in SSTA is made near $2{\mu}m$ diameter, we can save time and labour to measure the clay contents. Therefore, SSTA could be used as a more convenient method to get the same data as SM.

토성분석방법으로 사용되고 있는 표준비중계법 (Standard Method ; SM)과 개선비중계법(Simplified for Soil Texture Analysis ; SSTA)및 간이계산법(Simplified Clay Fraction Piocedure;SCFP)간의 $2{\mu}m$ 점토함량을 비교하고자 본 시험을 수행하였다. 사용된 시료는 점토함량이 2~40% 내외의 토양 28점이었다. 현재 국내사용 표준방법은 particle size Distribution을 위한 것이지, 토성판정을 위한 $2{\mu}m$ 점토함량을 계산하는데는 약간의 문제가 있는 것으로 판단되었으며 표준분석법과의 상관을 볼 때는 개선비중계법과 간이계산법 모두 1.0에 가까운 상관계수를 보였으나, 간이계산법의 경우 표준분석 법보다는 $2{\mu}m$ 점토함량이 0~2%정도 높게 평가 되었다. 또한 분석한 시료의 토성판정결과 표준분석법과 개선비중계법은 28점 모두 동일한 결과를 얻었으나, 표준분석법과 비교할 때 간이계산법은 28점중 4점이 다른 토성으로 판정되었다. 그러므로 표준분석법 방법보다는 개선비중계법 방법이 $2{\mu}m$ 점토함량을 측정하는데 더 신속하고 정확한 방법이 될 수 있을 것으로 판단되었다.