ChileanJAR

Sulphuric, acetic, nitric, phosphoric and citric acids were applied to a Santiago soil, an alluvial Mollisol, in order to decrease soil pH. All acids were effective in acidifying the soil except the citric acid. Nitric and acetic acids increased the soil electrical conductivity to restrictive levels for plant growth. Sulphuric and phosphoric acids were the most effective in reducing soil acidity. Drip irrigation with water acidified with sulphuric acid to a pH 4.5-5.5 maintained low pH of the soil solution in the planting hole through three growing seasons, when alkaline carbonates had been previously removed from the holeo Irrigation with acidified water stopped nitrogen losses in the soil fertigated with urea and increased available soil iron.