A field experiment was carried out at Instructional Farm of Indira Gandhi Agricultural University Raipur (C.G.), during the Kharif season of 2019. The study entitled “Studies on potassium fraction as influenced by nutrients management practices under rice-wheat cropping system” was carried out under the long term fertilizer experiment in the Vertisol. The objectives of the study were - to study the distribution of various fractions of potassium in Vertisol, potassium balance in the soil and correlation between yield and K fractions.The experiment was consisting of five treatments and four replications in a randomised block design (RBD). The treatments were T1 (control with 0:0:0 kg/ha N: P2 O5: K2O), T2 (general recommended dose for rice 100:60:40) T3 (STCR based inorganic fertilizer to achieve target yield 5 t ha-1), T4 (STCR based inorganic fertilizer to achieve target yield 6 t ha-1), and T5 (STCR based inorganic fertilizer with 5 t ha-1 FYM to achieve target yield 6 t ha-1). Fertilizer prescription equations used for the calculation of fertilizer for a definite targeted yield of rice variety MTU-1010 in Vertisol were developed by AICRP on STCR, IGKV, Raipur as FN= 4.05T- 0.57SN- 0.78ON, FP= 1.46T- 3.09SP- 0.31OP and FK= 1.61T - 0.10SK- 0.14OK. Among all the treatments, significantly higher water soluble K content (23.2 kg ha-1) was found in the treatment- T5 while lowest water soluble K were found with the control ( 8.79 kg ha-1). Exchangeable fraction of potassium were also observed highest (676.2 kgha-1) with the treatment -T5 which was found at par with treatment -T4 and observed significantly superior over other treatments (T1, T2, T3). Lowest exchangeable-K (610.1 kgha-1) was found in the control treatment. Improvement in water soluble and exchangeable-K fractions in the soil were may be due to the continuous application of balanced fertilization (with or without FYM). Highest value of non-exchangeable-K (2324 kgha-1) was observed in the treatment -T4 and found at par with the treatment -T5 (2311 kgha-1) and treatment -T2 (GRD). These treatments (T2, T4 and T5) were found significantly higher over the treatment- T3. Lower non-exchangeable potassium in the treatment- T3 was may be due to the long term application of lower doses of potassium. Significantly lowest non exchangeable –K was observed with control (1848 kgha-1). Overall finding shows that the highest values of all fractions of potassium were recorded in the treatment-T5 and lowest was found in the control. Apparent K balance influenced nutrients management practices under rice-wheat cropping system in Vertisol revealed that, the highest negative balance (-115.9 kg/ha) were recorded in organic treatment T5 followed by treatment T4 and T2 and lowest (-32.6 kg/ha) were found in treatment control. This is due to the fact that K application seldom matches K removal, resulting in greater dependence on soil K. Among different K fractions non-exchangeable potassium was observed as the most important potassium fraction contributing towards grain yield by rice. It contributes 95% variation in grain yield.