To calculate Nmax for crop types not listed in the Guidelines for Farmers in Nitrate Vulnerable Zones pack, use 
the links below to find the nitrogen recommendation for the crop types you are growing.
Nmax for these crops should be derived using the tables and guidance particular to the crop types you are growing.
SAC Technical Note 623, Fertiliser Recommendations For Soft Fruit And Rhubarb Crops
http://www.sac.ac.uk/mainrep/pdfs/tn623fertiliser.pdf
SAC Technical Note 621, Fertiliser Recommendations For Vegetables, Minority Arable Crops & Bulbs
http://www.sac.ac.uk/mainrep/pdfs/tn621fertiliser.pdf