Effects of farmyard manure compost and biodynamic preparations
since 1992 Potatoes
Third period (research focus: Yield formation and long-term effects)
| CM | CMBD | MIN | low | medium | high | |
| deg 10 ¹ deg 14 |
29.4 35.6 |
23.7 32.1 |
26.6 37.4 |
25.7 30.5 |
26.6 37.6 |
27.4 36.9 |
| ext 48 ² | 71.67 b | 65,2 b | 105.31a | 75.82 a | 80.36 ab | 86.01 b |
| cond 1 ³ cond 3 cond 9 |
689 1158 ab 1272 |
689 1117 b 1258 |
718 1239 a 1331 |
652 a 1105 1206 a |
719 b 1203 1318 b |
725 b 1205 1337 b |
| ¹ degradation after 10 and 14 days (% DM loss) ² extract darkening (extinction after 48 hours) ³ electrical conductivity (µS/cm) after 1, 3 and 9 days |
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Some degradation tests found a greater durability of organically fertilized potatoes. |
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| Extinction of potato extract with composted manure (CM), manure with biodynamic preparations (CMBD) and with mineral fertilization (MIN), evaluated for 48 hrs. in November 1999 |
Extract darkening was investigated in later years, too. The extract of manure fertilized tubers had a lower extinction than the tubers grown with mineral fertilizer. This difference occurred immediately at the beginning of the test with the fresh extract (E0) as well as during the following two days (after 24 hours, E24; after 48 hours, E48) when darkening continued with all samples, but to different extents. While increasing manure levels reduced darkening, higher rates of mineral fertilizer intensified the dark colour. The figures show the results of November 1999 as an example. Similar results were obtained in the three years 1997, 1998 and 1999.
Note:
A literature summary of results with an evaluation of pros and cons of degradation tests has been published by: RAUPP, J. (1998): Examination of some microbiological and biochemical parameters and tests of product quality used in a long-term fertilization trial. Amer. J. Alternative Agric. 13, 138-144
Click here for brief information on the methods of degradation tests.