In the European Union, groundwater should contain less than 50 mg of nitrate/L. Individual countries have developed alternative strategies for phosphorus (P). In The Netherlands, regulations based on P limited the amount of manure applied per hectare. A more balanced P supply to the land has been achieved by transport of manure from surplus to deficit regions. Costs of processing of manure to p...

Alum (Al2(SO4)(3).14H2O) additions to poultry litter result in lower ammonia (NH3) volatilization and phosphorus (P) runoff; however, the long-term effects of alum on soil P behavior have been unknown. The objectives of this study were to evaluate the long-term effects of poultry litter, alum-treated litter, and ammonium nitrate (NH4NO3) on P availability in soils and P runoff. Two studies were...

Soil disturbance of wildlands sites during construction or erosion often results in loss of nutrientrich topsoils and decreased plant available nitrogen (N). When soil organic matter is removed, the content, decomposition and cycling of organic N within soils is also decreased, reducing long-term sources of plant available N. Yard waste composts are a potential resource for replacement of deple...

[1] Nitrogen isotopes provide integrated information about nitrogen cycling in terrestrial ecosystems. This study explores the regional patterns of ecosystem N abundance along a 1200 km transect in Inner Mongolian grasslands and their relationships with climate. Results indicate that climatic variables control approximately 50% of the variation in ecosystem N abundance along the transect. Ecosy...

Cattle slurry was surface-applied to bare soil in two experiments in the period September­ November 1987, while in April-May 1988 two experiments were carried out in which the slur­ ry was mixed with the upper 6 an of the soil with a cultivator immediately after spreading. The 1987 experiments both lasted 18 days, the 1988 experiments 9 days. A micrometcorologi· cal technique, which did not dis...