A Method to Determine Soil-Entrapped Denitrification Products in Submerged Soils
- J. C. Katyal,
- L. S. Holt and
- A. M. Gadalla
To measure the contribution of soil-entrapped gases to denitrification in submerged soils, a soil-filled cylindrical bag (7 cm in height by 5-cm diam) made from stiff polyester cloth net was positioned in the center of potted Crowley silt loam soil. Denitrification of 15N-labeled KNO3 (14.85 atom % excess, applied at 100 kg N ha−1) was complete in 16 d after fertilization; 71% of the KNO3 was denitrified, mainly as N2 gas, with 41% trapped in the soil and 30% present in the headspace. Although no significant change in denitrification occurred during the subsequent 8 d, 15N recovery from soil-entrapped gases declined (from 41.2 to 28.4%), whereas that from gases present in headspace increased (from 29.6 to 43.9%). Regardless of time of sampling, around 90% of the 15N was recovered. These results demonstrate that in situ placement of soil-filled polyester cloth net bags before fertilization is a practical approach for sampling submerged soils to assess the contribution of soil-entrapped gases to denitrification loss.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © .