International Journal of Plant & Soil Science

Phosphorus fixation refers to the process by which phosphorus (P) becomes unavailable for plant uptake by reacting with soil minerals. In soils, phosphorus is primarily fixed by forming insoluble compounds with aluminum (Al) and iron (Fe) in acidic soils, or with calcium (Ca) in alkaline soils. A field experiment was conducted “Identification of critical phosphorus level change in red soil by influence of different organic material in black gram” at Ranadevi farm under Centurion University of Technology and Management Paralakhemundi, Gajapati, Odisha, India. The experiment was laid out in Completely Randomized Design (CRD) with nine treatments and three replications were vermicomposting, poultry manure and cow dung manure. The observations on growth characteristics, number of leaves, number of nodules, and phosphorus in each pot recorded. Plant height was observed increase with the application of vermicompost at 10 and 30 tons per hectare (T2 and T4), relative compared to the control and other organic treatments, especially during the early growth phase (15-45 DAS). The highest number of leaves 7 was recorded in T3 and T8, while the fewest (5) were noted in T6 and T9. Intermediate results ranging from 6 to 6 leaves were obtained from the other treatments. Cow dung manure considerably boosted root nodule production at 45 and 60 DAS, particularly when administered at 20 tonnes per hectare (T9).  All treatments demonstrated a significant decrease in phosphorus content. The highest phosphorus content (35 kg /ha) was recorded in T7, while the lowest value (6 kg P kg /ha) was observed in the control (T1).