Soil Interpretations Field Project of Soils Patancheru, Andhra Pradesh, India Environmental Pedology DE Spring 2010 K.S. Winans ICRISAT Center Patancheru, AP, India Semi-arid tropical climate Receives approx. 800mm annual rainfall Mean monthly rainfall exceeds mean potential ET Characterized by dry savannah vegetation Avg. min. temperature 19C and max. temp. 32C 1736N, 7816E m elevation Fig B. Site map Site 2 Site 1 Distance apart: Approx m Site1: 626 m Site2: 653 m Approx 25 km to the N, NW we see Manjira river. In the last 10 years a lot of development has taken place and tributaries of this river no longer flow in to the study area. Site1: occurs at the lower pediment of coarse granite gneiss; at the foot slope Site 2: occurs at shallow depressions-- granite-gneiss complex pediment covered by basalt outwash or alluvium deposits; at floodplain Alfisol site view (Site 1) Vertisol site view (Site 2) Alfisol profile view Vertisol profile view PROFILE: SOIL ONE: ALFISOL Horizon Lower DepthTextureStructure Dominant Color A Fig. A 2280% sand 6%silt 14%clay Sandy loam weak, subangular, sm roots, fine irregular pores, loose and friable Yellowish red 5YR 4/6 BE Fig. B 3467% sand 5% silt 28% clay Clay loam mod- med subang blocky; hard and friable; gradual smooth boundary; fine irreg. pores; sm roots Red to Dark red 2.5YR 3/6 Bt1 Fig. C 5742%Sand 6%Silt 52%Clay Gravely clay Strong coarse subang blocky; hard and friable; gradual smooth boundary; fine sm roots; tubular pores; quartz gravel Dark red 2.5YR 3.5/6 Bt2 Fig. D 11045%Sand 4%Silt 51%Clay Gravely clay Strong coarse subang blocky; friable; abrupt boundary; discontinuity; few very fine sm roots tubular pores; quartz gravel Dark reddish brown 2.5YR 3/4 Bt3 Fig. E 12045%Sand 4%Silt 51%Clay Gravely clay mod- med subang blocky; hard and friable; gradual smooth boundary; tubular pores; quartz gravel Dark red 2.5YR 3.5/6 FIG. F FIG. E FIG. D FIG. C FIG. B FIG. A FIG. G Weathering Soil 1: Alfisol: fun features and some interpretations well drained with moderate permeability moderate to high hydraulic conductivity >150cm seasonal water table depth slight limitation for septic tank absorption fields slight limitation for local roads and streets moderate infiltration rate non to slight erosion occur on gently sloping pediment of coarse grained granite-gneiss basement complex Foot slopes FIG. A FIG. B SOIL PROFILE: SOIL TWO: VERTISOL Horizon Lower DepthTextureStructure Dominant Color A Fig. A 2523% sand 20%silt 57%clay Clay coarse, strong prismatic structure to weak subangular blocky peds, clear smooth boundary Dark gray 10YR 3/1 Bkss1 Fig. B 5323% sand 20%silt 57%clay Clay coarse, intersecting slickenslides breaking to Strong coarse angular blocky peds, diffuse boundary lime concretions Dark gray 10YR 3/1 to Dark Grayish brown 2.5Y 4/2 Bkss2 Fig. C 5742%Sand 6%Silt 52%Clay Clay coarse, intersecting slickenslides breaking to strong coarse angular blocky peds, diffuse boundary few lime concretions, iron - manganese concretions Dark gray 10YR 3/1 FIG. C FIG. D Soil 2: Vertisol: fun features and some interpretations moderate to imperfectly drained with moderate very slow permeability moderate to high hydraulic conductivity 25 to