The use of near infrared spectroscopy in carbon and nitrogen mineralisation studies [Elektronische Ressource] / von Hans Peter Hartmann

The use of near infrared spectroscopy in carbon and nitrogen mineralisation studies Vom Fachbereich Gartenbau der Universität Hannover zur Erlangung des akademischen Grades eines Doktors der Gartenbauwissenschaften – Dr. rer. hort. – genehmigte Dissertation von Dipl.-Phys. Hans Peter Hartmann geboren am 04.10. 1969 in Hamburg 2002 Referent: Prof. Dr. H. Stützel Koreferent: Prof. Dr. T. Appel Tag der Promotion: 07.12.2001 Abstract In order to achieve a significant reduction of environmental harmful nitrogen losses from agricultural soils or vegetable growing production systems, the calculation of N-fertilizer supply has to take into account not only the crops nitrogen demand and the soils mineral N content, but also the amount of easily decomposable organic nitrogen compounds. The turnover of these compounds can be calculated by the use of simulation models. But the quantification of the organic compounds in the soil is mostly done by time-consuming and labour-intensive incubation experiments. Their results often do not meet the needs of simulation models for parameterisation. Thus, they actually are rarely used for the prediction of nitrogen mineralisation in soils. A simple determination of these compounds is also necessary for the direct estimation of nitrogen release without the use of simulation models.