Maintaining creeping bentgrass (Agrostis palustris) turf quality during the hot, humid summers of the southern United States is quite challenging (5). Equipment manufacturers and golf course superintendents assert that air movement through the soil profile reduces summer bentgrass decline by cooling the root zone and increasing the oxygen available to roots.
- Subsurface air injection increased turf quality, density, rooting depth and root dry matter at the end of summer, three years after establishment of the green.
- A-1 and Crenshaw improved in quality as much as older varieties Pennlinks and Penncross when they all received subsurface air injection.
- Severe root-zone temperatures were moderated somewhat by the air injection.
The most obvious result of air injection on turf quality was a reduction in dead turf. Shoot density also increased. Similar increases in shoot density occurred in September the year before, but aeration in that year did not result in an overall increase in turf quality. Surprisingly, enhancements in turf quality and shoot density were no greater in the old cultivars than in the new cultivars.
Air injection also improves the gas composition of the root zone. Carbon dioxide, which is toxic to plant roots, accumulates in the root zone when soil temperatures are warm (4). Earlier research on our green demonstrated that subsurface air treatments reduced carbon dioxide to ambient levels minutes after injection began, and levels remained low for hours after injection ended (3).
Better rooting probably increased turf quality by providing greater access to water and nutrients.
Substantial increases in bentgrass quality and rooting occurred with subsurface air injection at the end of summer in the third growing season. Severe root-zone temperatures were moderated somewhat by air injection. Deeper and more extensive rooting contributed to better turf quality and increased shoot density.
Beard, J.B., and W.H. Daniel. 1965. Effect of temperature and cutting on the growth of creeping bentgrass (Agrostis palustris Huds.) roots. Agronomy Journal 57:249-250.
Beard, J.B., and W.H. Daniel. 1967.Variations in the total, nonprotein, and amide nitrogen fractions of Agrostis palustris Huds. leaves in relation to certain environmental factors. Crop Science 7:111-115.
Dodd, R., B. Martin and J. Camberato. 1999. Subsurface cooling and aeration. Golf Course Management 67(9):71-74.
Ervin, E.H., and B.S. Corwin. 1999. Carbon dioxide: culprit in bentgrass summer decline? Golf Course Management 67(4):66-70.
Nus, J. 1994. Microenvironment manipulation. Golf Course Management 62(1):204-209.
Trusty, S., and S. Trusty. 1998. Hot town, cool bentgrass. Golf Course Management 66(4):186-191.