Detalhes do Documento

Green manuring is probably the only option for extending on a great scale the acreage of organic fanning in the perennial crops of the Mediterranean basin such as olive groves. Olive growers, in general, do not have animals so the availability of organic manures is not sufficient to maintain soil fertility. In addition, the organic composts approved for organic farming on the market have high prices and are sometimes speculative, in relation to their fertiliser value (Rodrigues et al., 2006). In NE Portugal there is a long tradition in the cultivation of white lupin (Lupinus a/bus) as a means of improving soil fertility. However, little is known about the dry matter yield and N fixation potential of lupin in these agrosystems, and also of the transfer of fixed N to the trees. In this work the results of dry matter yield and N recovery by lupin, vetch (Vicia villosa) and a mixture of self-reseeding annual legumes are presented. The trial also included plots of oats (Avena saliva) and natural vegetation.