ifoam'96 Book of Abstracts 11th IFOAM Scientific Conference 11-15 August 1996, Copenhagen, Denmark

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Workshop

Biodynamic Preparations on Grasslands: Soil Response.W13/P3

1) Fernando Gonzalez Bernaldez Research Centre, E-28791 Soto del Real; 2)Department of Ecology, E-28040 Madrid; 3) Department of Chemistry andAgricultural Analysis, E-28040 Madrid.

To improve the sustainability of the livestock farming systems in a mountain area with very high natural values the response of soil conditions under mediterranean permanent grasslands to the application of the biodynamic preparations was studied after two years of experiment(1992-1994).
A set of four 50 m2 plots (two control and two treated) with a latin square lay-out was established in three commercial farms located in the southern slopes of the Sierra Guadarrama (NW Madrid, Spain) at 750, 1050 and 1460 ma.s.l. respectively. The biodynamic preparations were applied according to the recommendations of the biodynamic method: compost preparations as cowpat pit (M. Thun), and the two field sprays. The repetitions and timing oft he applications were done according to local conditions at every altitude every year. Soil samples were taken from every plot before the experiment started (spring 1992) and two years later (spring 1994). Two depths were considered in all cases: 0-5 cm and 5-10 cm. Several physical, chemical and biological parameters were measured before and after the experiment started to evaluate the effect of biodynamic preparations on soil conditions.
However from the point of view of the texture the soils of the three farms were all the same, sandy loam, the coarse fraction (2 mm) in the soil samples makes a big difference among them: 40% at lower altitude, 20% at middle altitude and 10/30% (upper/lower depth) at the upper altitude. During the considered period, slightly wetter than before and after, plots untreated showed a natural tendency to improve its conditions at lower and middle altitudes but getting worse at higher altitude. The plots treated showed more clear improvement at lower altitude than at middle altitude. At the higher altitude the damage was also more clear with the application of biodynamic preparations but mainly at the upper layer (0-5 cm). These results are discussed in relation with the data available in the literature on arable soils under bio-organic versus bio-dynamic treatments.