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TitleEvidence for lunar-sidereal rhythms in crop yield: a review
Publication TypeJournal Article
Year of Publication2001
AuthorsKollerstrom, N, Staudenmaier, G
JournalBiological Agriculture and Horticulture
Start Page247
Keywordscalendar, lunar, rhythm
In 1956, Thun developed a procedure of sowing according to the position of the Moon in front of the twelve zodiacal constellations. These constellations were classified into four groups according to the element (Earth, Water, Air and Fire) astrologically associated with them. Root, leaf, flower and fruit crops were found to show increased yields if sown when the Moon stood before Earth, Water, Air and Fire constellations, respectively. Thun's philosophy of sowing by this sidereal rhythm has become a major component of biodynamic planting calendars, even though the founder of biodynamic agriculture, Rudolf Steiner, had only mentioned positive effects of the Full Moon in an agricultural context. In 1990, Spiess published a three-year study claiming to find effects of other lunar rhythms but not those of the 27-day sidereal month. This paper reviews published confirmations of the ‘Thun effect’ and reanalyses data concerning planting times and crop yields from Spiess's study with radish and carrots, by computing yield values as deviations from a moving average rather than as deviations from seasonal trends estimated by quadratic functions. The re-analysis showed an increase (ca +7%) in the yield of radishes which were sown in Earth constellations for his 1982 trial, with a comparable result demonstrated on re-analysing data from three years of carrot trials.