Redistribution of Alkalinity in Sand-Based Putting Green Soils.

Bicarbonate in irrigation water has been implicated in the buildup of carbonate in the soil, where there is concern that these minerals may precipitate and reduce porosity, leading to decreased hydraulic conductivity. Much of the research on this issue originates from the arid southwestern U.S., yet recommendations for managing bicarbonate are made to golf course superintendents in all regions of the U.S., despite the vast differences in climate and soil pH across the country. In this study, putting green profile samples were collected from 30 golf courses around the U.S., and analyzed for pH and carbonate content by depth. Soil carbonate content was not significantly related to total bicarbonate addition from irrigation water, but soil pH was. There were significant pH and carbonate gradients by depth in the profiles of most sites, and there was a strong relationship between pH and soil carbonate content. In soils with acidic pH values, carbonate contents were very low, and in soils with a pH above 7.0, carbonate content was highly variable. These findings suggest that carbonate accumulation is not a concern for acidic soils. Implications for nutrient and water management are discussed.