Soil fertility evaluation after paddy cultivation under integrated nitrogen management and nitrification inhibitor application in wetland ecosystems

A field study was conducted over two successive kharif seasons (2022 and 2023) at the Regional Research Station Farm of Anand Agricultural University, Anand. The experiment followed a Randomized Block Design with three replications. The results revealed that the treatments had no significant effect on soil pH1:2.5, EC1:2.5, available potassium (K2O), iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) after paddy harvest during both years and in the pooled data. The pooled average over the two years demonstrated consistent outcomes, with treatment T12 recording the highest soil organic carbon content (0.375%), which was statistically comparable to treatments T6, T10, T4, T13, T7, T11, and T5. In contrast, T1 (absolute control) showed the lowest organic carbon content (0.305%), significantly lower than all other treatments. T1 also exhibited the lowest available nitrogen level (177 kg ha-1), while T8 recorded the highest value (225 kg ha-1), statistically similar to T6, T7, T12, and T13. These treatments (T6, T7, T12, and T13) also showed significantly higher phosphorus content, ranging from 47.66 to 47.81 kg ha-1. In comparison, T1, T2, and T3 (control and sole ammonium sulphate treatments) recorded significantly lower phosphorus levels, all below 45 kg ha-1.