Restoring streams on farmland – a win-win story
A comprehensive programme of sustainable land management, on a hill farm catchment in the Waikato, has proved that sound environmental practices can improve both stream water quality and farm economic performance – a win-win for farmers and the environment.
The land-use changes made on the Mangaotama catchment included planting radiata pine in the steepest parts of the catchment, intensification of beef and sheep farming on better land, riparian fencing and planting, and protection of native forest remnants, including pest control.
The outcomes: greatly enhanced per hectare returns from land remaining in grazing, better long-term financial performance of the farm, plus a host of improvements in water quality. Annual sediment loads in waterways declined by over 70%, and phosphorus and organic nitrogen loads fell by over 60%. There were lower levels of faecal indicator bacteria, lower annual stream temperatures in reaches downstream of pine and riparian plantings, and better macroinvertebrate community health in streams.
The project was overseen by a Catchment Management Group of 20 people, including NIWA’s Dr John Quinn, AgResearch, Landcare Research, farmers, and others. The group concluded that adopting water-sensitive agricultural practices can restoredegraded streams in rural hill catchments and enhance long-term financial performance. However, capital injection is needed to support the transition to more sustainable farming. The findings are relevant to large areas of hill farming country across New Zealand.
The Foundation for Research, Science & Technology contributed significant funding to the project.