This work presents an overview of the principal models for estimating nutrient loss being used or developed in New Zealand. It emphasises models that deal with N and P losses from pastoral farming systems, particularly via leaching, and that may allow the handling of different farm management procedures.
Cichota. R, Snow. V O; Estimating nutrient loss to waterways—an overview of modelsof relevance to New Zealand pastoral farms. New Zealand Journal of Agricultural Research, 2009, Vol. 52: 239-260 2391175-8775 (Online); 0028-8233 (Print) /09/5203-0239
https://www.tandfonline.com/doi/abs/10.1080/00288230909510509