Grace Chibuike

Doctor of Philosophy, (Soil Science)
Study Completed: 2019
College of Sciences


Thesis Title
Investigating Nitrate Attenuation Capacity and Processes in Pastoral Hill Country Landscapes

Read article at Massey Research Online: MRO icon

Agricultural nutrients, particularly nitrate, degrade water quality in New Zealand and pose serious environmental and health issues. There is limited understanding of the capacity of pastoral hill country landscapes to reduce nitrate for improved water quality. Ms Chibuike investigated the influence of hill country landscape features on dissolved organic carbon concentration and the potential for nitrate loss via denitrification. She found that the Ramiha soil type has a high denitrification capacity due to its high capacity to store carbon, resulting from the presence of allophane. She also found that hill country seepage wetlands have a significantly higher denitrification capacity compared to other hill country features, and represent a valuable landscape feature which could be enhanced to improve water quality leaving hill country farms. Her research findings provide information that is critical for improving hill country nitrogen management for better water quality outcomes in New Zealand.

Associate Professor Lucy Burkitt
Dr Peter Bishop
Dr Mike Bretherton
Professor Marta Camps Arbestain
Associate Professor Ranvir Singh