Problem definition
In the fourth Dutch action program within the framework of the Nitrates Directive, phosphorus use from fertilisers, manures and soil amendments depends of the phosphorus status of agricultural land. The phosphorus use standards in the action plan is differentiated according to soil P status. Soil P status is divided into three classes, namely 'low', 'neutral' and 'high'. The boundaries between these classes are based policy considerations and phosphorus fertiliser recommendations based on soil testing. For arable land the boundary between low and neutral is set at Pw value <36 mg P2O5 / l. As part of the fifth action program within the framework of the Nitrate Directive the boundary between the class low and neutral might be set at a lower value to become more in line with the classification of soil phosphorus in current fertiliser recommendations. The agricultural and environmental implications of lowering the limits of a soil P class for the area culture land involved, the implication and perspectives for an agronomic and environmentally sound use of manure and development of the soil phosphorus status on the long term are not sufficiently known.
Research objectives
The goal is to determine what the agricultural and environmental consequences are of a change of soil P classes by means of a number of scenarios for P management as function of soil P status of arable land.
Results and products
Public report available on internet http://www.alterra.wur.nl/UK/publications/ Brochure with main findings, conclusions and recommendations. |
