Biodynamic Preparations on Grasslands: Grass Response S29
Colmenares, Ricardo1; De Miguel, Jose Manuel2.
1) Fernando Gonzalez Bernaldez Research Centre, E-28791 Soto del Real; 2) Department of Ecology, E-28040 Madrid.
|To improve the sustainability of the livestock
farming systems in a mountain area with very high natural values the response of
mediterranean permanent grasslands to the application of the biodynamic preparations was
studied during a three and a half years period (1992-1995).
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 of the applications were done according to local conditions at every altitude every year. The grass biomass protected under mobile cages was sampled every month. The plant species composition of grasslands was estimated on springtime every year.
Beside farm management the fluctuations of meso and interannual climatic conditions among the different localities were the main factor affecting the three parameters considered here: Grass Production, Grass Water Content and Plant Species Diversity. For the whole experimental period plots treated with biodynamic preparations presented higher Mean Grass Production in the farms located at middle and lower altitude but it was lower in the one located at higher altitude. For the same period, Mean Grass Water Content in the plots treated was lower in all the three farms. Plant Species Diversity calculated by the Shannon-Weaner Index was nearly the same in the plots treated and untreated.
The results, availables for the first time for permanent grasslands, are discussed in relation to the role of biodynamic preparations as growth regulators improving plant nutrition therefore providing a higher quality (nutrient balance), higher yields under certain conditions and no significant impact (in the short term) on plant species diversity in mediterranean permanent grasslands.