SFF Project Summary
Sustaining environmental integrity of South Island irrigated dairy farms
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Quarterly Update: to March 2004
Project Description
The objective of this project is to deliver new practical and effective farm management practices to improve productivity on dairy farms under irrigation with minimal impact on the environment.
Lincoln University has established a new 650 cow commercial dairy farm that will develop and test practical methods to improve the efficiency of fertilisers, water and supplementary feed. The farm's environmental objective will be achieved by measuring and managing leaching losses of nitrogen and phosphorus from the farm.
Problem/opportunity that the project is addressing
A major challenge to New Zealand's growing dairy industry is to achieve an annual productivity gain of 4% in order to remain internationally competitive. It is important to ensure that this productivity gain is achieved without comprising the quality and integrity of NZ's clean and green environment. A major community concern with the expanding dairy industry in the South Island is its potential to threaten the quality of ground and surface waters. It is critically important to measure the losses of nitrate and phosphate to water resources on a commercial dairy farm, and develop management practices to minimise these losses from free draining soils above sensitive aquifers.
The new Lincoln University irrigated dairy farm provides a unique opportunity to use the latest environmental monitoring technologies to provide reliable information on leaching losses of nitrate and phosphate from fertilisers and farm dairy effluent under irrigated conditions. The farm spans several soil types, typical of those used for dairy farming in Canterbury and North Otago. The latest 'soft-top' monolith lysimeters and tile drain systems equipped with automatic samplers are also being established on the farm. Impacts by farming practices on nutrient leaching losses will be recorded in 'real time' to provide immediate feed back on the sustainability of new farm management practices. Best management practices can then be developed, and these new practices transferred to the wider farming community.
Quarterly Update to March 2004
Introduction and Objective
This project will deliver best management practices under irrigation, by transferring the latest environmental monitoring systems onto a commercial dairy farm. This will ensure that the productivity gains are achieved in a sustainable way, and that the wider environment is protected.
Groundwater monitoring wells
Samples of groundwater have been collected from monitoring wells installed in 3 clusters and analysed for nitrate, nitrite, ammonium, phosphate, E. coli, and Campylobacter.
- The water from the monitoring wells show that the concentration of nitrate in the aquifer below the farm is increasing and the latest value (13 mg N/L) is higher than the concentration in the aquifer entering the farm (< 10 mg N/L).
- The phosphate concentrations in the groundwater are unaffected by the farming operations and are generally below 50 mg P/L (ppb).
- There has been no Campylobacter or E. Coli detected in the groundwater samples over the past 3 months.
Work is continuing to define the groundwater movement and mixing under the irrigation area.
