Denitrification Losses from Kentucky Bluegrass Sod

Abstract

Denitrification may represent an important mechanism in the fate of N applied to turf. Denitrification losses were directly measured from fertilized 'Baron' Kentucky bluegrass (Poa pratensis L.) sod samples sealed in acrylic chambers using the acetylene inhibition technique. Losses were correlated with soil texture, percent soil sat· uration (SAT), and temperature. Losses from turf on a Hadley silt loam soil and Hadley silt soil (both coarse-silty, mixed, nonacid, mesic Typic Udifluvents) incubated at 2rC did not exceed 0.4 and 0.1 %, respectively, of the applied potassium nitrate fertilizer (4.5 g N m-2 ) when soil water levels were less than 75% saturated. Soil saturation increased denitrification losses from the silt loam and silt soils to 2.2 and 5.4% of the applied N, respectively. The relationship between percent soil saturation and denitrification loss was quadratic and highly significant for both soils. .70] existed between denitrification losses and soil temperatures between 22 and 30°C in the silt soil at 75% of soil saturation. Soil temperatures of 30°C or greater coupled with saturated soil conditions resulted in the greatest losses, equiv alent to 44.6 and 92.6% of the applied N to the silt loam and silt soils, respectively. Denitrification losses did not increase at soil tem peratures above 30°C. These results indicate that denitrification loss from fertilizers applied to turfgrasses may not be a serious problem unless the soils are saturated and at higher soil temperatures.

Influence of temperature on the composition and activity of denitrifying soil communities

“…As shown in laboratory experiments, temperature can directly affect denitrification. The effect was found to be different in different soils, but in the majority of studies, denitrification activity and temperature were positively correlated (Nömmik, 1956; Bailey, 1976; Jacobson & Alexander, 1980; Mancino et al ., 1988; Colbourn, 1993; Saad & Conrad, 1993b; De Klein & Van Logtestijn, 1996; Maag & Vinther, 1996; Gödde & Conrad, 1999). Generally, temperature can either alter the functioning of existing organisms without changing the soil microbial community or restructure communities and thus modify the fundamental physiologies that drive biogeochemical processes (Schimel & Gulledge, 1998).…”

Nitrous oxide emission as affected by tillage, corn-soybean-alfalfa rotations and nitrogen fertilization

“…The magnitudes of N 2 O emissions from a soil are dependent on soil NH 4 + and NO 3 --N concentrations (Rolston 1981), water content (Aulakh et al 1984), temperatures (Mancino et al 1988), available C (Rolston 1981), pH (Koskinen and Keeney 1982) and aeration (Groffman and Tiedje 1991), as well as time of year the measurements are made (Cates and Keeney 1987). These properties depend not only on soil type, but also on agricultural management.…”

Denitrification estimates in monoculture and rotation corn as influenced by tillage and nitrogen fertilizer

“…Denitrification loss is related to soil properties such as NH 4 -and NO 3 -N concentrations (Rolston et al 1978;De Klein and Van Logtestijn 1994), water content (Aulakh et al 1984;Davidson 1992), temperature (Mancino et al 1988), available C content (Rolston 1981), pH (Koskinen and Keeney 1982) and aeration (Groffman and Tiedje 1988). These properties depend not only on soil type, but also on tillage practices, crop rotations, and N fertilization (Rice and Smith 1982;McKenney et al 1993).…”