Journal of the Indian Society of Soil Science

Coarse textured soils of Rangareddy district were collected from thirty locations and analyzed for potassium (K) fractions. A greenhouse experiment was conducted with the collected soils to know the response of cauliflower to K application. The level of extraction of K by different extractants followed the order: boiling HNO₃ (1 M) > NaBPh₄ (0.2 M) > citric acid (0.01 M) > NH₄OAc (NN) > oxalic acid (0.01 M) > acetic acid (0.01 M). The amount of K extracted by different extractants was more in sandy clay loam soil of Mominpet and very low in sandy soils of Emamguda. The NH₄OAc extracted an amount of 54.2 to 242.3 mg kg⁻¹ with an average of 130.3 mg kg⁻¹ and it showed highly significant correlation with 0.2 M NaBPh₄ extractable K (r = 0.926^**), plant K uptake (r = 0.931^**) and also with curd yield (r = 0.975^**) of cauliflower. The mean K uptake in the soils ranged from 0.65 g plant⁻¹ on Emamguda soils to 1.67 g plant⁻¹ on Mominpet soil. Mean curd yield was 352.4 g plant⁻¹ in the control which showed a significant increase to 454.8 g plant⁻¹ with the application of 66.6 mg K₂O kg⁻¹ soil. The mean response to the application of K was 25.3 kg cauliflower curd per kg of K applied.