Mineralogy and Nutrient Status of Teak-Growing Soils

In the South Balaghat Forest Division (Madhya Pradesh) two pedons belonging to the Udic and Typic Inceptisols were studied for sand mineralogical properties and nutrient status in order to know if the soil was a causative factor for the poor growth of teak. The genetic characters of the two pedons indicate similarity in site, topographic and other conditions. Both the Udic and Typic varieties reveal that the soils are somewhat deficient in available nitrogen and phosphorus. Mineralogical assemblages of two sand fractions (0.25–0.10 and 0.10–0.05 mm) show light minerals comprising quartz, micas and feldspars. Based on comparative heavy minerals, the Udic inceptisol is characterised by staurolite and tourmaline and Typic inceptisol by hornblende, staurolite and tourmaline mineral assemblages. Differences in the distribution of minerals in the two size fractions reveal that as the grains becomefiner the plagioclase feldspars and hornblende decrease while garnet, tourmaline, epidote, staurolite, kyanite and zircon increase. The sand mineralogy and elemental analysis show good inherent fertility of the two pedons impeded drainage, high clay content along with shrink-swell property, calcareous concretions, paralithic contact and high pH in the Typic variety are the factors responsible for the poor growth of teak.