Quoted from: Gilhespy, Sarah L., Steven Anthony, Laura Cardenas, David Chadwick, Agustin del Prado, Changsheng Li, Thomas Misselbrook et al. "First 20 years of DNDC (DeNitrification DeComposition): model evolution." Ecological modelling 292 (2014): 51-62. https://doi.org/10.1016/j.ecolmodel.2014.09.004 

NZ-DNDC is a modified version of DNDC that includes a number of alterations to best reflect the conditions found in New Zealand and was developed by Saggar et al. (2004). The presence of distinctive and diverse soil types within a short distance and soils having a higher organic C content than the world average; coupled with climatic conditions and grazed pastoral systems (grazing 24 h a day) which differ from many other countries meant that the application of the DNDC model to New Zealand was challenging. NZ-DNDC was based on an early version of DNDC and comprised four sub-models to simulate soil-climate, crop growth, decomposition, and denitrification. Several modifications were made to the model to allow for southern hemisphere conditions (Saggar et al., 2004). NZ-DNDC was further modified by Saggar et al. (2007) to model the entire suite of the interactions among plants, soil, atmosphere and management in an intensive grazed grassland system. The major modifications were related to pasture crop growth, N input from animals, evapotranspiration and soil moisture regime.