Details zur Publikation
Kategorie Textpublikation
Referenztyp Buchkapitel
Titel (primär) The evidence of carbon dynamics in soil, investigation in pot and model experiments
Titel (sekundär) Resource management in fragile environments
Autor Körschens, M.; Weigelt, A.
Herausgeber Behl, R.K.; Gupta, A.P.; Khurana, A.L.; Singh, A.
Erscheinungsjahr 1997
Department BOFO
Seite von 123
Seite bis 132
Sprache englisch
Keywords Carbon; soil; model experiments
Abstract Carbon is the most essential prerequisite for soil formation, soil fertility and soil productivity. In arable farming systems crop and root residues are the main source for Soil Organic Matter (SOM). Carbon and nitrogen content in the soil are subject to changes depending upon crop, yield, fertilization, soil and climatic conditions and the resulting mineralisation intensity. However, these changes run very slowly. In the Static Fertilization Experiment at Bad Lauchstädt (loess black earth, start 1902) due to a constant treatment after about 70 years an equilibrium of the C and N content has adjust. The difference of the Corg content between the extreme variants "without fertilization" and "30 t FYM every 2nd year + NPK" amounts 0.66%. In 1978 a part of the experiment was recognised in this way, that the different SOM levels of the seventy years running fertilization variants were used as new initial levels. On this basis it was possible to test the effect of different organic and mineral fertilization treatments on the Corg content in dependence of the initial level.
The ommission of any fertilization at a high initial level lead to a decline of the Corg of 0.14% (from 2.25% to 2.11 %). In case of unchanged fertilization the initial level stayed the same. Organic/mineral fertilization at a low initial level lead to an increase of 0.33% Corg (from 1. 74% to 2.02%). A continued omission of fertilization did not cause a further decline of the low Corg level. It is obvious, that after 16 years significant changes took place, the new equilibrium, however, is not by far reached. Similar investigations were carried out in a long-term pot experiment under field and greenhouse conditions. Over a period of 13 years (1982-1995) 3 different soil types taken from long-term experiments of 2 different SOM levels were tested. Under field condition in all cases, also at the high initial SOM level, an increase of the C content is to detect. Under greenhouse conditions only the Corg content of the low SOM level of sand and loam has increased. The increase can be explained by the high root mass in the pots. While the decrease in treatments under greenhouse conditions is caused by a much higher mineralisation intensity than under open field conditions. Changes of the C content in soil as a consequence of varied management run very slowly. Their direction depends on the initial level. It will take a lot of decades until a new equilibrium will adjust. The same treatment can cause at a high initial level a decline, but at a low initial level a rise of the .SOM content. The amount of decomposable carbon is determined to a vital degree by the mineralisation intensity. Under normal agricultural practice it is between 0.2 to 0.6%·. An optimum SOM content in the soil, which on the one hand guarantees a high productivity and does not cause ineffective C02 emissions is a global objective.
dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=9416
Körschens, M., Weigelt, A. (1997):
The evidence of carbon dynamics in soil, investigation in pot and model experiments
In: Behl, R.K., Gupta, A.P., Khurana, A.L., Singh, A. (eds.)
Resource management in fragile environments
CCS HAU, Hisar & MMB, New Dehli, p. 123 - 132