Influence of Portland cement amendment on soil pH and residual soil termiticide performance

Abstract

Soil adjacent to new brick veneer work is likely to have a higher pH owing to the mixture of cement with the soil. In the Gainesville, FL, area, soil samples taken from such locations had a range of pH values from 9.0 to 10.1; similar soils used in bioassays had a pH of 5.6 before the addition of cement. Addition of 15 mg of Portland cement to 33 g of soil increased the pH to 6, and addition of 291 mg of Portland cement increased the pH to 9. The pH of soil amended with cement was stable for the first 5 months. After 10 months, soil pH values decreased from alkaline to near neutral in all cases. Eastern subterranean termite workers, Reticulitermes flavipes (Kollar), were exposed to the treated soil at pH 6-9 for 24 h, and percentage mortality was recorded at 5 days, 5 months and 10 months. Termite mortality significantly decreased at higher soil pHs for bifenthrin, chlorpyrifos, fipronil and imidacloprid treatments at 5 months and similarly for bifenthrin, permethrin, chlorpyrifos, fipronil and imidacloprid treatments at 10 months. There was an inverse linear relationship between soil pH and mortality. Increased soil pH diminished residual activity of termiticide in the following order: imidacloprid > fipronil > chlorpyrifos = bifenthrin > permethrin > cypermethrin.

Recovery of Imidacloprid from Leachate and Soil

“…Adsorption is directly influenced by soil organic matter acting as a sink whereby gradual availability of a termiticide is diminished by time. Richman et al (2006) found inverse relationship between soil pH and mortality in which increased pH diminished residual activity of termitcides.…”

“…Because soil conditions adjacent to structures where termiticide is applied accelerated dissipation and biological transport (by plants), both might factor in persistence of imidacloprid-treated soils (Scholz and Spiteller 1992, Rouchard et al 1994, Sarkar et al 2001, Richman et al 2006. Adsorption is directly influenced by soil organic matter acting as a sink whereby gradual availability of a termiticide is diminished by time.…”

Influence of Humic Acid on the Strength of Cement‐Soil and Analysis of Its Microscopic Mechanism

“…According to the Powers [34][35][36][37] theory, as the hydration reaction proceeds, the volume fraction of hydration products increases, reducing the sample's pore volume. Increasing OH − ion concentration during cement hydration reaction will increase the pH value [38]. HA is soluble in dilute alkaline solution, partially dissolves HA particles during soaking, increasing pore volume [39].…”

Ultrasonic Dispersion of Nanocarbons in Soil-water Mixture

“…The pH of NCs is slightly below 7. This is acidic in nature, and thus, is not expected to raise the pH of UKM soil when compared to lime or cement is used for stabilization [31]. With a pH of 4.14, the soil is strongly acidic and can produce better dispersion of NCs due to the presence of hydrogen ions.…”