Phosphorus and Potassium Fixation and Recovery Rates in Different Land Use Systems of Ravine and Tablelands of South Eastern Rajasthan

Soil phosphorus (P) and potassium (K) fixation and recovery rate was studied in different land use systems of ravine and tablelands in Chambal valley of south eastern Rajasthan. Results showed that P and K fixation increased in all the land use systems. The fallow land and Aonla (Emblica officinalis) orchard showed highest P (95%) and K (93%) fixation. Tableland except for forest area showed highest K fixation rate (90–96%) compared to ravine areas. Potassium fixation percentage decreased with increase in added K levels but sudden decrease was observed after 200 mg K kg⁻¹ level. The low recovery of P in these soils indicated high fertilizer P rate required per unit increase in available P in fallow and Aonla orchard (4.26%) and lowest in ravine land plantations (2.24%). Similarly, fertilizer K rate required per unit increase in available K in soil was highest in Aonla orchard and fallow land (3.24%) and lowest ravine plantations (2.36%). Overall, this study will provide fixation and recovery rate with added P and K levels thereby helping to formulate best management practices for P and K fertilization and computing optimum P and K requirement for tablelands of degraded ecosystems of India.