Influence of various wetting agents on water status in USGA greens as determined by their physical properties
Abstract
Soil hydrophobicity is an increasing issue in sandy soils, affecting agricultural land and golf courses. This phenomenon causes water repellency and bypassing of hydrophobic root zones, limiting water accessibility. Due to golf course putting greens utilizing a sand-based rootzone, soil water repellency commonly occurs, leading golf course superintendents to apply wetting agents to mitigate its effects. Over 75 percent of the wetting agents currently on the turfgrass market do not list their active ingredients, which limits the predictability of their performance in the rootzone. These studies investigated how various wetting agents influence water's physical properties, such as surface tension ([gamma]), to predict the effect of wetting agents on water infiltration or retention. The determination of the [gamma] of 23 different wetting agents led to the hypothesis that wetting agents with [gamma] values [less than or equal to] 30 mN m-1 have greater influence on water infiltration; those between 30 to 40 mN m-1 influence both water infiltration and retention; and those [greater than or equal to] 40 mN m-1 have greater influence on water retention. Three studies were conducted based on the surface tension categories to determine a correlation between: 1) selected wetting agents' water infiltration and rewettability into water-repellent sand; 2) to evaluate selected wetting agents' influence on water infiltration and retention under field conditions; and 3) to determine selected wetting agents' influence on water movement and leaching through water-repellent sand utilizing a soil water tracer. Our results contradicted our original hypothesis that [gamma] alone cannot be utilized to predict a wetting agent's functionality, however demonstrated that other factors need to be assessed. Abbreviations and key words: infiltration; leaching; rewettability; soil hydrophobicity; soil water tracer; [gamma], surface tension; water movement; water repellency; water retention; wetting agent
Degree
Ph. D.