Sulphur in the form of elemental sulphur, sulphur dioxide, sulphuric acid, urea- sulphuric acid mixtures, ammonium thiosulfate and ammonium polysulfide, is known to improve the physico-chemical properties of calcareous soil.
In the soil, elemental sulphur is changed into sulphuric acid which reacts with calcium carbonate. As a result of this reaction calcium is freed and replaced with sodium in the soil and increase the water infiltration.
2S + 3O2 + 2CaCO3 + 4NaX = 2CaX2+2Na2SO4+2CO2
CaSO4 + 2NaX = CaX2 + Na2SO4
H2SO4 + CaCO3 + 2NaX = CaX + Na2SO4 + CO2 + H2O
There are some nutrients into the alkaline and calcareous soils, which change into insoluble forms and decrease the plat nutrients uptake. These substances include, manganese, phosphorous, iron, zinc etc. This type of uptake is increased by elemental sulphur for the high agricultural productivity.