This project will evaluate a range of catch crop species and establishment techniques to reduce sediment and surface flow losses following the winter grazing of forage crops. Trials will be carried out on hill country in the Hawkes Bay and Horizons regions, but the systems developed will provide spill-over benefits to all farming regions and terrains nationally.
This project will provide a detailed understanding of the value of catch-crops, both economically and environmentally, by sediment control and reducing overland nutrient losses entering waterways. The project will highlight relevant establishment techniques, grazing systems, and what catch crops work best in which environments.
Background
Typically, winter forage crops are grazed off by livestock then the paddocks are left to fallow until spring. Catch crop refers to a short-term crop that is established before, during or after a winter crop is first grazed off and before the next main crop or new pasture is established. A catch crop would cover the whole area grazed after each break and requires repeated sowings as new ground is progressively grazed off.
Catch crops are a practical solution to reduce sediment losses by reducing the amount of bare ground, thereby reducing runoff and sediment loss. Catch crops physically hold the soil, trap any surface flow and help with soil aeration and structure, thus reducing soil movement, sediment and nutrient loss. As sediment acts as a vector for phosphate, catch-crops will also reduce phosphate losses.
For more information about this project, updates and results visit: https://www.catchcrop.nz/
Benefit for farmers
This project will provide robust information on the management and benefits of catch-crops that will be applicable across all New Zealand and terrains. Workshops and extension material will be produced in the final year of the project.
Timeline and investment
Initially this was a three-year project due for completion in June 2021. However, due to a very dry winter in the middle of this project, there was not enough sediment run off to reliably conclude results so this project will run for one more year and now be due for completion in June 2022. This will provide two years of sediment mitigation data under different conditions and provide a more substantive analysis of the mitigation impacts of catch crops.
The project will be centered on sites in the Hawkes Bay Regional Council and Horizons catchments with more detailed measurements around sediment losses and productivity benefits. The first and second year are focused on data collection and proof of concept. The third and final year will be more focused on extension with some final trial work as needed. B+LNZ investment into this project is $37,000 over the duration of the project.
Partners
This is a Ministry for Primary Industries Sustainable Farming Fund project led by AgFirst (Lochie MacGillivray) and co-funded by MPI, Hawkes Bay Regional Council, Horizons Regional Council, Ravensdown Ltd, B+LNZ, Foundation for Arable Research and in-kind support from Farmland Ltd, Dairy NZ and Catch Crop Sediment Mitigation Group.
Lead Scientist: Brendon Malcolm (Plant and Food Research).
Farmers involved: Mark Watson, Philp Holt, Ben Harker, Damien Reynolds, Robbie Hill, Andrew Russell, Will Morrison and Brownrigg Agriculture.
B+LNZ point of contact: Mark Harris and Cara Brosnahan.