Soybean potential yield (Glycine max (L.) Merr.) is determined by temperature, radiation, photoperiod and genotype in every location. The variability of potential yields is strongly associated with changes in available solar radiation through years. Selection of management practices that lead to maintaining high yields are:genotype, sowing date and row spacing. Sowing date enables coupling solar radiation offer with the crop stages were yield is defined. Furthermore, potential yield for every environment depends on genotype.

Since 2001/2002 there has been a formidable expansion of annual crops in Uruguay which has determined changes in land use, with a strong expansion of soybeans (Glycine max) under no-tillage. Improperly managed crop production systems can be an important nonpoint source of pollution, accelerating eutrophication of surface waters resulting from nitrogen and phosphorus (P) inputs. Nutrient losses depend on many factors such as climate, soil characteristics and management practices.

Since 2001/2002 there has been a formidable expansion of annual crops in Uruguay which has determined changes in land use, with a strong expansion of soybeans (Glycine max) under no-tillage. Improperly managed crop production systems can be an important nonpoint source of pollution, accelerating eutrophication of surface waters resulting from nitrogen and phosphorus (P) inputs. Nutrient losses depend on many factors such as climate, soil characteristics and management practices.

Livestock production in Uruguay involves the management of C4-species dominated natural grasslands, which cover more than 70% of the country's surface area. Almost 80% of the farms specialized in beef and wool production are family farms, which usually exhibit low sustainability due to low family income and grassland overgrazing.

Only 0,6 % of Uruguayan land is under somehow protection such as National Parks or Protected Landscape. In this context wild life and biodiversity conservation in general depends on private areas which major part are under different production systems. T

Crop production in Uruguay has changed significantly in recent years, not only in terms of expansion of cultivated area but in its main features. These changes came along with significant increase in land prices and agricultural inputs causing intensification on land use. In order to get high profits the traditional crop-pasture rotations should be strongly oriented to a continuous cropping system and strengthened on grain crops.

Crop production in Uruguay has changed significantly in recent years, not only in terms of expansion of cultivated area but in its main features. These changes came along with significant increase in land prices and agricultural inputs causing intensification on land use. In order to get high profits the traditional crop-pasture rotations should be strongly oriented to a continuous cropping system and strengthened on grain crops.

Estimating total crop water use and the associated variability are critical for planning, for the design of supplementary irrigation strategies and for subsequent management. Tough there have been great advances in estimating actual evapotranspiration, achieving accurate estimates at the field level is still a challenge. The characterization of site specific characteristics influencing evapotranspiration like soil properties impose a great challenge to the use of modeling, and the accurate characterization of the variability within a field of crop status may bias estimates.