Effect of Topography on Characteristics, Fertility Status and Classification of the Soils of Almora District in Uttarakhand

摘要

Topographic position is one of the most dominant factors that govern soil development in the hilly areas. Ten soil profiles representing different landform units i.e. hill top, side slope, broad valley and narrow valley terraces were chosen to investigate the soil morphological, physical and chemical characteristics and their relationships with topography in Almora district of Uttarakhand. Soil properties varied remarkably among the studied profiles. The soils were moderately shallow to very deep indepth (32-160 cm), non-saline (EC 0.03-0.45 dS nr'), acidic in nature (pH 5.1-6.6), low to high in organic carbon (OC) (0.03-2.91%) with low to moderate CEC [1.6-19.4 cmol(p+)kg']. Base saturation ranged from 45.9 to 75.1% in which calcium (Ca2*) and magnesium (Mg2f) were the dominant cations on exchangeable sites followed by potassium (K+) and sodium (Na+). The studied soils were dominated by silt fraction followed by clay, except in Dhamas (P4), Dhaili (P5) and Kosi (P10) which showed high sand content. Hill top profiles showed the highest OC. The upper soil layers of hill top and broad valley terrace profiles showed higher availability of soil macronutrients, whereas micronutrients were higher than agronomic critical limits in all profiles. Three soil profiles were classified as Entisols and keyed out as Typic Udifluvents (Kosi), Lithic Udorthents (Dhamas) and Typic Udorthents (Dhaili). Majkhali (P7) soils were placed under Inceptisol soil order and were classified as Dystric Eutrudepts. The remaining soils were placed under Alfisol soil order and keyed out as Hapludalf at great group level. Among the Alfisols, Someshwar (P9) was classified as Oxyaquick Hapludalfs, Sitlakhet (PI) was classified as Ultic Hapludalfs, Salla Routela (P2) and Chaubattia (P3) were classified as Mollic Hapludalfs, while Kausani (P6) and Hawalbagh (P8) soils were keyed out as Typic Hapludalfs. The soils in Almora district of Uttarakhand exhibited wide variations with topographic positions and proper soil management willhelp in maintaining sustainable production of this area.