Lysimeter Investigations on the Effect of Winter Catch Crops and Weeded Fallow on the N-Dynamics in a Sandy Treposol Soil of Northeast Germany |
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Authors: | W. Merbach D. Hölzel G. Schalitz J. Pickert H. J. Jacob C. Latus |
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Affiliation: | 1. Zentrum für Agrarlandschafts- und Landnutzungsforschung, Institut für Rhizosph?renforschung und Pflanzenern?hrung , Müncheberg;2. Zentrum für Agrarlandschafts- und Landnutzungsforschung, Forschungsstation Paulinenaue , Müncheberg;3. Zentrum für Agrarlandschafts- und Landnutzungsforschung, Lehr- und Versuchsstation für Grünland- und Futterwirtschaft , Paulinenaue , Germany;4. Zentrum für Agrarlandschafts- und Landnutzungsforschung, Institut für Landnutzungssysteme und Landschafts?kologie , Müncheberg |
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Abstract: | Abstract Lysimeter experiments (soil: sandy treposol, from the region “Havelländisches Luch”, Brandenburg, Germany) with application of 15N labelled fertilizer (80 kg N per ha as 15NH4 15NO3, 10 at.-%15N exc.; for simulating mineralization in the early autumn period) were carried out to determine to what extent the amount of mineral- N was temporary conserved by winter catch crops, taken up subsequently in the vegetation periods by following crops, taken by subsequently in the vegetation periods by following crops, or percolated in the leaching water, respectively. The results were as follows: 1) Until winter or spring respectively, the catch crop uptake rates of applied mineral-N were 32% for phacelia (Phacelia tanacetifolia BENTH.), 25% for winter rape (Brassica napus L. cv. ‘AKELA’), and 16% for white mustard (Sinapis alba L.). 2) In the year after, following maize incorporated from 2.1 to 4.5% of the fertilizerborne N. The following plant community of fallow took up from 0.2 to 0.5% N originating from the fertilizer-N. 3) In comparison with the catch crops, N-leaching losses under fallow conditions were highest and equivalent to 17% of the applied fertilizer-N amount. In contrast to 3% of white mustard, phacelia and winter rape reduced N-leaching losses to 0.2 and 0.3% of the applied fertilizer-N amount. 4) In spring of the first year after the beginning of investigations, N-leaching losses were highest under fallow conditions and white mustard cultivation. Thus, the amounts of nitrate losses would exceed the EU limit for drinking water. 5) Three years after the investigations had been started, 10% (white mustard) and 20% (fallow) of the applied fertilizer-N was still found in th lysimeter soil. |
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Keywords: | Brassica napus L. catch crops fallow groundwater N-leaching lysimeter investigations nitrogen 15 Phacelia tanacetifolia BENTH Sinapis alba L. |
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