See more from this Session: Soil and Plant Analysis: Tools for Improved Nutrient Management II
Wednesday, October 19, 2011
Henry Gonzalez Convention Center, Hall C, Street Level
Many soils have too high pH for acid loving plants to grow optimally. Hence, it becomes necessary to reduce soil pH accordingly. The causes of high pH are overliming, free Ca/Mg carbonate parent materials and high concentrations of OH<sup>-1</sup>, HCO<sub>3</sub><sup>-1</sup> and CO<sub>3</sub><sup>-2</sup>. There are many organic and inorganic materials that are used to reduce soil pH. But there is a lack of a rapid method to determine the amount of acidifying materia(s) that can be applied to soils of different texture, CEC and organic matter content to reach a target pH. The objective of this study was to develop a rapid laboratory method that will determine the amount of an acidifying material(s) needed to lower a soil pH. Soil samples were equilibrated with 0.05M H<sub>2/sub>SO<sub>4</sub> and pH was measured in H<sub>2</sub>O, KCl and CaCl<sub>2</sub>. Also, soil samples were equilibrated with different concentrations of (Al)<sub>2</sub>(SO<sub>4/<sub)<sub>3</sub> and FeSO<sub>4</sub> and pH was measured. An inverse relationship to lime requirement of soils was developed that is similar to a lime requirement procedure to determine the amount of acidifying material(s) needed to reach a target pH.