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 19°C and max. temp. 32°C  17°36’N, 78°16’E  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 <50 cm seasonal water table depth  severe degree of limitation for septic tank absorption fields  moderate limitation for local roads and streets  mostly flood plain  gently sloping  moderate infiltration rate  non to slight erosion

Comparison Similarities  Slope  Permeability  granite gneiss pediment Differences  Concretions  Texture  Parent materials  Old volcanic deposits vs. Alluvium deposits