Gypsum, sulfur, and sulfuric acid for reclaiming an alkali soil of the Fresno series

This paper is a report of recent experiments in the use of gypsum, sulfuric acid, and sulfur in the reclamation of a severely affected alkali soil of the Fresno series. Effects of the soil correctives on the yield of irrigated pasture are compared statistically.

Treatment consisted of applications of the chemicals on the basis of the same sulfur content (1.86 tons) per acre. Resulting yields of the sulfuric-acid plots (5.70 tons H₂SO₄ per acre) were markedly higher than those of the gypsum (10 tons per acre) and sulfur plots over the two-year period following treatment.

Yields of the sulfur plots were never significantly higher than those of the check plots, probably because the sulfur had not had time to oxidize. Yields of the gypsum plots were significantly higher than the sulfur-plot yields for the initial cuttings, but 20 months after application there was no significant difference.

Reduced H₂SO₄ applications on the same soil (2.85 and 1.42 tons per acre) also gave pronounced beneficial effects. Greenhouse experiments indicate that improvement may be expected from applications as small as 0.4 tons H₂SO₄ per acre.