Effect of Azolla on Soil Properties and Yield of Mungbean (Vigna radiata L.)

Pot and incubation experiments were conducted to investigate the effect of green manuring with Azolla on properties of soil and its ultimate effect on yield of mungbean. Incorporation of fresh Azolla at levels (6, 12, 18 and 24 t ha⁻¹) decreased significantly pH and bulk density, but increased water holding capacity, organic carbon, NH₄-N, NO₃-N, available P, K, Ca and Mg. pH, bulk density and water holding capacity of the soil remained almost the same at 10, 20 and 30 days whereas K decreased and organic C, available Ca and Mg increased from 10 to 30 DAI of Azolla. Number of pods, weight of pods and grain yield/plant increased significantly up to 12 t ha⁻¹ only and these attributes were found to be positively correlated with levels of Azolla incorporated.