AGWAPLAN Side 1 · · Good Agricultural Practices (GAP) - a user friendly manual Hans Spelling Østergaard Danish Agricultural Advisory Service Dep. of Plant production

AGWAPLAN Side 2 · · GAP is a catalogue of measures to reduce loss of nutrients to water bodies. It contains a short description of each measure and a link to further information What is a GAP - manual?

AGWAPLAN Side 3 · · The short description of the GAP-manual includes the following key-points: a description of each measure and where it is relevant the effect of each measure on efficiency of N and P in plant production leaching of N ammonia volatilization loss of P crop quality and economy What is a GAP - manual?

AGWAPLAN What is a GAP - manual? Side 4 · ·  The GAP-manual also includes a spreadsheet: Calculation of nitrate leaching Calculation of ammonia volatilization Evaluation of different methods to reduce loss of P

AGWAPLAN What is a GAP - manual? Side 5 · ·  !!!  Calculations are based on existing and commonly accepted knowledge  Calculations are table look-up’s – not a new model  We want to put figures on, i. e. quantitative estimates

AGWAPLAN An example – nitrate leaching Area Soil type Measure Reduction, kg N per ha Reduction, total on farm, Kg N 1621 Ammonia instead of nitrate fertilizer Early sowing of winterwheat in autumn Catch crops Ammonia instead of nitrate fertilizer n. r.- 71Ploughing in spring Total on farm-2206 Input: - Average precipitation (high, middle or low) - Soil type - Farm type (plant-, pig- or cattleproduction)

AGWAPLAN What is a GAP - manual? Side 7 · ·  !!!  Table look-up’s are mutually independent  More or less independent of soil and farm type  Skilled user is necessary

AGWAPLAN Thank you for your attention