However the enactment of EU directives to restrict nitrate levels in drinking water is leading to guidelines and legislation on N use beginning to appear in most countries. However the regulations are applied differently and vary between countries. In Switzerland there is a new approach of assessing N balances on the whole farm level, rather than on single crops. In this way unavoidable N losses from some crops can be compensated by crops that use N more efficiently. In general terms regulations are usually very strict around watersheds used for drinking water.
All regulations require the keeping of records of the rates and timings of fertiliser application.
Such activity is leading to the need for the development of national recommendation systems for vegetable crops where they are currently unavailable. Current Fertiliser Advice Systems for Vegetable Crops Participant Current Fertliser Advice Systems 1. N-index system used by ADAS 2. Advisory board system 2. Nmin system 3.