Prediksi Pengembangan Tanah Berdasarkan Nilai Cole serta Hubungan terhadap Liat, Kalium, dan Magnesium Tukar pada Tanah Ultisol dan Inceptisol

Abstract

Changes in soil volume are caused by clay minerals that will expand when wet and shrink when dry. Therefore, the identification of clay mineral properties of agricultural soils is very important because these properties are related to the estimation of soil fertility potential. One of the clay minerals is montmorillonite. Montmorillonite is a type of mineral that has a role in the process of soil wrinkling that can be predicted simply by determining the COLE value in a soil. The author is interested in conducting research to identify the types of clay minerals in Ultisol and Inceptisol soils from Siborong borong sub-district, North Tapanuli Regency, North Sumatra Province. This study aims to know simply the type of clay minerals contained in the soil. Soil sampling is done by random sampling technique and analysis in the laboratory. Soil samples were taken at 16 locations with a depth of 0-20 cm and 20-40 cm. The total number of soil samples taken is 32 samples. Furthermore, the soil was analyzed in the laboratory with the parameters of soil COLE value, soil texture, soil pH, K-dd, and Mg-dd. The results showed a strong correlation between soil texture (clay fraction) and COLE value. The soil had acidic and mildly acidic conditions and the sandy loam soil texture dominated the entire sample.