Para el caso de Uruguay, una limitante para el adecuado manejo de la fertilización fosfatada radica en el bajo ajuste del método Bray I para algunos suelos del país o con distinta historia de fertilización. Además, la siembra directa modifica la dinámica de P en el suelo, con una marcada estratificación dentro de la capa arable del suelo. Como consecuencia de dicha estratificación se ha sugerido una profundidad de muestreo menor (0-7,5 cm) a la convencional como forma de no subestimar la disponibilidad para los cultivos.

The continue increase in world population, coupled with the environmental problems caused by the use of fossil fuels, has led to the search of new sources of renewable energy. Among these, is the use of eucalyptus biomass grown on short rotation coppice for energy production, in which all the components of the tree are harvested. Based on this, some questions arise:Can we call renewable energy the one in which all the components of the tree are removed from the soil every four year? What are the consequences from the nutrient cycling point of view?

The association between genetic resistance of lambs to gastrointestinal parasites (GIP) with dry matter intake (DMI) average daily gain (ADG) and residual feed intake (RFI) was studied. Sixty-four Corriedale lambs (357±14 days old), from divergent lines for resistance to GIP (27 resistant-R and 37 susceptible-S) developed by the Uruguayan Wool Secretariat were used. The animals were allotted to one of five outdoor pens, they were stratified by sex, body weight, and sire.