Response of sunflower to sulfidic materials and magnesium sulfate as sulfur fertilizer

The potentiality and effectiveness of Sulfidic Materials (SM) and Magnesium Sulfate (MS) as sources of sulfur in relation to the growth of sunflower (Helianthus annus L.) cultivated in two sulfur deficient soils were evaluated under pot experiment. The SM and MS were applied at the rates of 0, 25, 50 and 75 kg S ha^-1. The best growth and yield performance of sunflower were attained by the SM₇₅ treatment in both the Sirajgonj (e.g., seed yield: 43.2 g/plant) and Gazipur (31.3) soils, followed by the SM₅₀ (30.3 Sirajgonj, 22.4 Gazipur) > MS₇₅ (25.2 Sirajgonj, 22.3 Gazipur) treatments. The application of SM₇₅ increased (increased over control = IOC) the flower bead diameter and seed yield by 80 and 169% in the Sirajgonj soil and 77 and 182% IOC in the Gazipur soil, respectively. But the equivalent amount of MS₇₅ increased those parameters by 41, 56% and 21, 100% IOC in both the soils, respectively. Almost similar and significant (p≤0.05) effects were observed for the other yield parameters of sunflower grown in both the soils. The application of SM increased the organic matter from 0.66 to 1.26% in the Gazipur soil and from 0.77 to 0.98% IOC in the Sirajgonj soil, regardless of the application rates. The application of SM also enhanced sulfur and organic matter status of the soils and these increments were more pronounced in both the soils till the final harvest at maturity of sunflower, reflecting a good indication for its long term use instead of the chemical fertilizer.