Total elemental composition and primary particle size distribution of soils in relation toparent rocks and landforms

Abstract

A study on total elemental composition of soil primary particles in relation to parent rocks and landforms inGadag (taluk), Karnataka was conducted during 2018-19. Horizon-wise soil samples were collected and analysed for majorand trace elements content in sand, silt and clay. Granite gneiss derived upland soils were higher in sand fractions than schistand decreased with depth. The silt fraction in lowland soils of granite gneiss were higher than schist. The depth wise siltdistribution was irregular. Clay fraction was higher in schist derived lowland soils than granite gneiss and increased withdepth in most of the pedons. The sand fraction had higher total content of Si and K, while total content of Al, Fe, Ca, P, Mg,S and Mn were higher in clay fraction and these elemental contents increased with depth except Si, which remained higherin surface horizons. Total content of Si, Al and K were higher in granite gneiss derived lowland soils than schist, whereastotal content of Fe, Ca, P, Mg, S and Mn were higher in schist derived lowland soils than granite gneiss. The relativedominance of elements in granite gneiss derived soil particles in decreasing order was, Si followed by Al, Fe, K,Ca, Mg, P,S and Mn.Whereas in schist, Si was followed by Al, Fe,Ca,K,Mg, P, Mn and S. The total content of all the elements in soilparticles increased from upland to lowland irrespective of parent rocks.