Influence of elemental sulfur and/or inoculation with sulfur oxidizing bacteria on growth, and nutrient content of sorghum plants grown on different soils

Abstract

A pot experiment was conducted to study the effect of elemental sulfur(E.S) rates (300 and 600 ppm) and/or sulfur oxidizing bacteria (S.O.B. ATCC 8158) on growth and nutrients content of sorghum plants grown on different soils (sandy soils(I & II) and clay loam soil). The obtained results could be summarized in the followings: Sorghum plants:  Significant increases over the control were observed in fresh and dry weights of sorghum plant as well as its content of SO4=, N, P, K, Fe, Mn, Zn and Cu by using all the sulfur and/or the oxidizing bacteria treatments.  Addition of E.S (300 & 600 ppm) in combination with S.O.B. ATCC 8158 significantly increased both fresh and dry weights as well as SO4=, N, P, K, Fe, Mn, Zn and Cu contents of sorghum plants grown on the used soils as compared with either of them alone.  E.S rates (300 & 600 ppm) significantly increased the fresh and dry weights as well as all the studied nutrients content (SO4=, N, P, K, Fe, Mn, Zn and Cu) of sorghum plants grown on the different soils as compared with S.O.B. ATCC 8158 treatment alone.  The highest rate of E.S (600 ppm) significantly increased all the previous parameters under study as compared with the lower rate (300 ppm).  The highest values of fresh and dry weights as well as nutrients content (SO4=, N, P, K, Fe, Mn, Zn and Cu) of sorghum plants grown on the used soils were obtained by 600 ppm E.S + S.O.B. ATCC 8158 treatment followed by 600 ppm E.S; 300 ppm E.S + S.O.B. ATCC 8158; 300 ppm E.S; S.O.B. ATCC 8158 and control treatments in decreasing order. The used soils:  E.S rates (300 & 600 ppm) and/or S.O.B. ATCC 8158 decreased pH values of the used soils after 3, 6 and 9 weeks from sowing as compared with their corresponding control treatments. The values of pH of sand soil (I) and clay loam soil slightly decreased by time i.e they decreased from 3 weeks to 9 weeks from plantation.  E.S rates (300 & 600 ppm) with or without inoculation the used soils with S.O.B. ATCC 8158 significantly increased SO4=, N, P, K, Fe, Mn, Zn and Cu content of all the used soils as compared with the control and sole S.O.B. ATCC 8158 treatments each alone.  The highest values of SO4=, N, P, K, Fe, Mn, Zn and Cu contents of sandy soils (I & II) and clay loam soil took the same trend of these nutrient in sorghum plants.  The highest rate of E.S (600 ppm) significantly increased SO4=, N, P, K, Fe, Mn, Zn and Cu contents in all the used soils as compared with the lower rates (300 ppm).All the values of fresh and dry weights as well as all the determined elements in sorghum plants and the used soils were higher when the clay loam soil was used than when the other two sandy soils (I & II) were used. This may be due to the fertility levels of these soils.