Tomato (Solanum lycopersicum L.) is an economically important vegetable crop in Karnataka and is highly susceptible to a range of insect pests and diseases. Consequently, chemical pesticides are frequently used to protect tomato crops and maintain productivity. However, repeated and inappropriate pesticide application may contribute to pesticide residues, soil-quality deterioration, disruption of beneficial microorganisms, development of pest resistance and occupational exposure. The present study was undertaken to assess pesticide-use practices in tomato cultivation in Chamarajanagara District, Karnataka, with particular emphasis on the physicochemical and microbiological characteristics of agricultural soils from the district. Soil samples representing five taluks Gundlupete, Chamarajanagar, Kollegala, Hanur and Yelandur were analysed for pH, nitrogen, potassium, organic carbon, phosphorus, magnesium, electrical conductivity, total bacterial count, yeast and mould count, and actinomycete count. The laboratory analyses were conducted in December 2025 using procedures referenced to the Soil Testing Manual of the Department of Agriculture and Co-operation, Government of India, and FAO methodology. The observed soil pH ranged from 7.52 to 8.38, indicating neutral to moderately alkaline conditions. Electrical conductivity varied substantially from 158 to 4200 µS/cm, while total organic carbon ranged from 0.10 to 1.92%. Nitrogen ranged from 112 to 261.07 mg kg⁻¹, potassium from 65 to 255 mg kg⁻¹ and phosphorus from 222.13 to 632.04 mg kg⁻¹. Considerable variation was also observed in microbial populations, with total bacterial counts ranging from 5 × 10⁶ to 1.1 × 10⁸, yeast and mould counts from 3 × 10⁵ to 8.8 × 10⁶, and actinomycete counts from 2 × 10⁵ to 5 × 10⁵. These findings demonstrate substantial spatial variation in soil characteristics among the selected taluks. However, the present laboratory dataset alone does not establish that the observed differences were caused by pesticide application. Farmer-level pesticide-use information, including active ingredients, formulation, dose, number of applications, application intervals and field history, is required to establish such relationships. The study provides a useful baseline for integrating pesticide-use surveys with soil quality and microbial assessment and for developing integrated pest management strategies for tomato cultivation in Chamarajanagara District.
