AgFirst is running a new project in the Hawke’s Bay investigating the impact of tile drains (referring to any sub-surface drainage) on water quality. All sectors need to be measuring and understanding their environmental footprints, and this project addresses the lack of horticultural data in this area.
Tile drains are used to divert excess moisture from the soil. This increases crop health both in winter (more oxygen to roots) and in summer (more roots survive increasing drought resilience). This is key to maintaining food security and increasing climate change resilience. This project seeks to understand whether nutrients are being lost below orchard root zones and carried into tile drains and draining into local waterways.
We hope this project enables us to better understand the impact of tile drains on water quality, so that, if needed, growers can implement the required management strategies to improve nutrient efficiency. This will benefit not only the environment, but also orchard productivity by addressing the loss of valuable soil or nutrients that are essential for crop growth.
The project will collect a three-year dataset on 16 farms in the Heretaunga Plains in Hawke’s Bay with varying horticultural land uses. It will set up two trial sites on each farm, enabling experimentation with new management strategies in year three on one site, while leaving the other as a control.
The Heretaunga Plains has been selected because it has extensive tile drainage networks and a range of groundwater pressures and soil types, and much of the catchment is used for high-value horticulture.
The AgFirst team is at the end of the site selection phase and will soon be moving on to preparing those sites for monitoring, planned to begin in September.
Nine co-funders, including Hawke’s Bay Fruitgrowers Association, have backed AgFirst to carry out the project, and have leveraged this money using the MPI Sustainable Food and Fibre Futures Fund.