Catch crops for reduced nitrate leaching

Previous research has shown that sowing a catch crop can reduce nitrate leaching losses by as much as 40%, as well as improving nitrogen use efficiency and farmers’ profitability. This project aimed to upscale this previous applied research into working winter crop rotations in Canterbury and Southland and adapt it to the various soil and climatic conditions.

Background

The use of catch crops is recognised as a potential tool to help reduce farmers’ nitrate leaching losses but without good guidelines, the successful adoption of such technology is likely to be disorganised with variable outcomes. 

This project was a farmer-led initiative to develop and demonstrate the use of catch crops in winter forage grazing rotations to lower the nitrate leaching footprint. Using catch crops successfully not only reduces nitrate leaching losses but increases nitrogen use efficiency and feed production on farm.

Key results

  • The introduction of catch crops into winter forage rotations can be both a practical and an economically viable farm management tool to help reduce nitrogen loss from winter forage grazing systems.
  • Timely sowing (as early as possible) with the appropriate winter-active species is important to make the most effective use of these catch crops.
  • High sowing rate are needed to get good nitrogen uptake, fast canopy closure and to produce a high yielding crop.

Benefit for farmers

This project established a practice of sowing winter catch crops as a normal part of winter forage management and demonstrated effective alternatives to farmers that lower nitrate leaching losses after winter forage grazing.

Timeline and investment

This was a three-year project with investment by B+LNZ of $30,000 over the duration.

Outputs

Farmer events

  • Three field days throughout the programme

Popular press articles

Scientific publications and conference proceedings

Resources

Partners

This is a Ministry for Primary Industries Sustainable Farming Fund project led by Lincoln Agritech and co-funded by MPI, B+LNZ, Ballance Agri-Nutrients, Ravensdown, Agricom, Luisetti Seeds with in-kind support from Craigmore Farms, Dairy Holdings, DairyNZ, Foundation for Arable Research (FAR), South Island Dairy Development Centre (SIDDC), Irrigo Centre Ltd, and Lincoln University’s Centre for Soil and Environmental Research.

Lead Scientist: Peter Carey (Lincoln Agritech).
Farmers involved: Bruce Taylor, John van Vliet, Gary McGregor, Shaun Wilson, Andrew Gorman, Clint Jordan, Simon Kelly, Chris Giles.
B+LNZ point of contact: Suzanne Keeling and Cara Brosnahan.