Studies on Genesis, Classification and Evaluation of Soils for Sustainable Land Use Planning in Yerpedu Mandal of Chittoor District, Andhra Pradesh

摘要

Seven typical pedons representing major land forms (uplands and plains) of Yerpedu Mandal in Chittoor district of Andhra Pradesh developed from granite- gneiss and alluvium parent materials under varying land uses were studied for their morphologicalcharacteristics, physical and physico-chemical properties. The soils were slightly acidic to moderately alkaline (pH-6.5 to 8.9) in reaction, non-saline, deep to very deep in depth and have iso-hyperthermic temperature and usitc soil moisture regimes. Texture, organic carbon, CEC and base saturation ranged from loamy sand to sandy clay loam in surface whereas sandy to clay in subsurface; 0.5 to 4.4 g kg"1, 8.80 to 30.67 cmol(p+)kg'1; and 37.73 to 88.06%, respectively. Soils were low to medium in available nitrogen and phosphorus, low to high in available potassium and sufficient in sulphur. The DTPA-extractable iron (Fe) was deficient whereas Cu and Mn were sufficient. However, the DTPA - Zn was sufficient in surface soils while deficient in sub-surface soils. The soils on very gently sloping (1-3%) topography exhibited the development of argillic horizon (Bt) whereas the soils on nearly level (0-1%) lands had cambic horizon (Bw). However, the Entisol pedons did not show presence of any diagnostic horizon. Soils were classified as Ultic Haplustalfs, Fluventic Haplustepts, Typic Ustipsamments and Typic Ustifluvents. All the soils of the study area fall under agricultural land with land capability classes ranging from II to IV. Further, the lands havelimitations of slope and erosion. On the basis of major soil constraints, suitable land use plan for Yerpedu Mandal was suggested for sustainable management.