Use of Molasses and Distillery Slops with Sulfur for the Reclamation of a Saline-Sodic and a Sodic Soil from Puerto Rico

Abstract

Data are presented on the effects of the use of molasses and distillery slops in conjunction with sulfur for the reclamation of a saline-sodic and a sodic soil from southwestern Puerto Rico. Results show that, in a sodic Guánica clay soil, corn yields were higher under the molasses treatment in the first corn crop, sulfur-slops and sulfur molasses in the second corn crop, and molasses, sulfur-slops, and sulfur molasses in the third crop, namely, snapbeans. Hydraulic conductivity values were markedly increased in the sulfur-slops and sulfur molasses treatments and removal of harmful exchangeable sodium was possible throughout the three crops. This was probably because of better water movement and the fact that more Ca ions were brought into circulation to displace adsorbed sodium. The experiments conducted on the saline-sodic Fe (Faith) clay soil followed about the same pattern of crop yields, hydraulic conductivity, and removal of exchangeable sodium of the Guánica clay soil. On the check plots, however, replacement of adsorbed sodium was rather pronounced for several possible reasons. These are: The soil had excess soluble salts which, for some time at least, maintained the colloids in a flocculated state. The soil column was rather short, 6 inches, and the hydrolysis of fertilizer salts must have brought into circulation Ca ions in an amount such as to replace considerable adsorbed sodium. Since Thiobacillus thiooxidans derives its energy from the oxidation of sulfur alone it is believed that the enhanced oxidation of sulfur must have been caused by created aeration and somewhat acid conditions which favored the bacteria.