The study, by NZLT and AgResearch staff, builds on the data and knowledge gained from the Pastoral 21 research, which was done on Telford’s dairy farm near Balclutha several years ago.
The new trial was being done on two paddocks belonging to Waitahuna sheep and beef farmers Ron and Carol Alderton.
Each was planted in swedes last season and had been resown in kale for next year’s winter grazing.
"The study analyses contaminant losses in the runoff from different winter grazing systems with the focus on the impact on critical source areas," Mr Simpson said.
The Ministry for Primary Industries’ Sustainable Farming Fund funded the study as there was no data available to determine what impact sheep have on vulnerable areas, compared with dairy cows.
Flumes, made from plywood, channelled the runoff to a central point where samples were then taken.
"We have the theory that as sheep are lighter so there will be less impact on the soil and less contaminant loss," Mr Simpson said.
Mr Alderton said they volunteered to be part of the study as they had been involved in the Ballance Farm Environment Awards for about 15 years.
He was also interested to find out what was happening on the farm with nutrient run-off.
"The Waitahuna is a relatively clean river and I think our impact on the environment may be overstated as we run an all-sheep operation with 10% of the farm in forestry in some of the gullies.
"This was an opportunity to find out the real impact and what is really happening.
"Being towards the end of my farming career it is a chance to contribute to this research and hopefully we can come up with something to improve the environment for future generations," he said.
As the study is in its first year, the information will provide baseline data.
The study
- 1000 ewe hoggets started grazing the first paddock on June 1 and then moved to the second on June 15.
- By July 24, the hogget mob was split into 560 stock units per ha for one paddock and 415 stock units per ha on the second.
- Two paddocks are being used, one with a critical source area of 1.17ha and the other with one of 0.81ha.