**Acknowledgements**

nitrogen. We recommend more efforts in introducing crops that require less inputs of nitrogen for growth (e.g. soya beans), and also in raising awareness of the need to reduce the fertilisation

In the organic farming, it is necessary to introduce fertilisation management based on the soil properties. Results show that outdoor vegetables production on shallow and sandy soil is not optimal agricultural practice from the drinking water protection perspective and is in certain

Grassland use is a good alternative to arable. Different methods of farming practices on grassland land use, also intensive ones, have according to national guidelines proved to be extremely beneficial from the nitrogen balance perspective. However, it is necessary, with the help of professional services, to clearly specify the amount and type of N fertiliser rate, which

Agricultural practices adjusted to the stricter WPA I regime considerably reduce the loss of nitrogen from the soil and do not impact the yield which remains stable. The current state represents a good balance between the benefits for good‐quality status of drinking water and

On the other side, we have less strict WPA II and III regime minimal effects on N leaching from arable land which could mean that producers cultivate land without any serious re‐ striction or they adjusted agricultural practices according to the requirements of the WPA

Measures of WPZ II and III regimes are virtually no different than the average convention‐ al production practices outside the WPZ. Since these two areas occupy the vast majority of WPZ and because we have, in regard to the commitments adopted from Water Framework Directive, achieved good‐quality status of groundwater throughout the aquifer, it is neces‐ sary to change the current approach of forming WPZ regimes. The current system for de‐ termining the WPZ regimes is positioned so that it fully ignores the characteristics of the

Assessing the impact of the scenarios was done with the knowledge of the uncertainties of the model. Uncertainties were associated with the establishment of production technologies, rotations, dates of harvest, grass‐cut dates, dates of mechanical tasks and dates of fertilisers' application. All these data are just an average estimate, as each farmer has their own time schedule and technology of production, which varies according to the type of crops, crop and livestock species, intensity of agricultural production and changing weather conditions. Additional uncertainty originates in soil maps, firstly because of spatial resolution, and secondly because the model requires information on wilting point, field capacity and hydraulic

According to the results, we suggest that future measures or WPA regimes are formed according to the type and properties of the soil and not only on the groundwater flow direction and proximity of drinking water wells. Constant communication with the land owners and cultivators in the area and their regular education is vital for successful trans‐

rates by their number and quantity.

130 Water Quality

situations even comparable to conventional production.

has to be dependent on the soil type and properties.

conductivity which are not part of standard soil map.

economic situation of agricultural holdings.

regulations.

soil.

Financial support for this study was provided by the Slovenian Research Agency founded by the Government of the Republic of Slovenia, Ministry for Agriculture, Forestry and Food, Contract number 1000‐10‐281058. The report is also available from e‐site: http://www.dlib.si/ details/URN:NBN:SI:DOC‐HWYIJSVV.
