Abstract

                                A total number of 201 surface soil samples were collected encompassingthe fields of Central Farm of Horticultural College and Research Institute,Periyakulam, Tamil Nadu. The GPS data (Latitude ºN and Longitude ºE) wererecorded for each sampling site by using GPS-Garmin eTrex Vista HCX model.Field maps were collected and field number wise digitization was done. Soilsamples were processed and anlaysed for soil physic-chemical and fertilityparameters. Results indicated that soil samples were neutral to alkaline inreaction, non saline, and slightly calcareous to non calcareous in nature.Soil fertility groupings under percent category indicated that the soils weremedium in soil organic carbon, low in available nitrogen, medium to high inavailable phosphorus, medium to high in available potassium, and low inavailable sulphur. With respect to DTPA extractable micronutrients, Fe, Zn,Mn and Cu were found to dominate by low to medium, low, high, medium tohigh categories, respectively. HWS-Boron was also recorded under the highcategory. The nutrient index values of the samples indicated a high status fororganic carbon, available P and K, while medium for available N and adequatefor available sulphur. With respect to micro nutrients, nutrient index valuesindicated that adequate for DTPA-Zn and very high for DTPA-Fe, Mn, Cu, andHWS-B. Thematic maps generated on the individual parameters depictedthe spatial variability of parameters in the Central Farm of HorticulturalCollege and Research Institute, Periyakulam. In the identified areas of poorfertility status, nutrient deficiency has to be eliminated by the applicationof organic and /or inorganic sources to maintain sustainable soil fertilitystatus. Soil test-based fertilizer recommendations and micronutrients areto be followed to mitigate nutrient deficiencies and achieve sustained cropproduction and soil fertility.

Key words : GIS; Nutrient status; Spatial variability; Thematic maps