Transformations of fertilizer nitrogen in soil |
| |
Authors: | F. W. Chichester |
| |
Affiliation: | (1) U.S. Soils Laboratory, Soil and Water Conservation Research Division, Agricultural Research Service, USDA, Beltsville, Maryland |
| |
Abstract: | Summary Five crops of oats were grown over a 14-month period on a Chester silt loam soil fertilized with N15-labelled (NH4)2SO4. All plant material from the first four crops was returned to the soil. Following a fifth crop, oat tops and roots were harvested, and the soil was subjected to repeated extractions by autoclaving in 0.01M CaCl2. The distribution of N15 and of indigenous soil N among chemical fractions of the extracts, and in the acid-soluble and acid-soluble and acid-insoluble portions of the soil residues following 0.01M CaCl2 extraction, was remarkably similar. Since appreciable equilibrations between added N15 and the more resistant forms of soil organic N is unlikely, it is postulated that fertilizer N became incorporated in newly-formed complexes, similar to those already present in the soil. This view is in harmony with the finding that percentage removals of total and N15-labelled N remained almost the same, even with recovery of approximately 55 per cent of the amounts originally present. N mineralization capacity of the soil was reduced appreciably as a result of extraction. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|