Written by Erik Frykberg
Massey University has extended its research into the leaching of nutrients by studying the actual water that drifts through soil.
It will take place at the sheep and beef research farm, Keebles, located near Massey's Manawatu campus, and comprising 287 hectares.
The programme will use a water and nutrient collection system, which sits underneath dedicated research paddocks, and allows all water to be collected and studied.
It will allow researchers to examine the effects of differing herbage types and/or stocking rates on leaching at the same time on the same type of soil.
The tests can also be carried out across the seasons and years.
The project is being led by Dr Lydia Cranston, Associate Professor Dave Horne, James Milner and Dr James Hanly.
"We are continuing to progress our understanding of what goes on beneath the soil in farms, but like any good research project, you need the right tools to measure it accurately," said Dr Cranston.
"We have known for quite some time that to measure nutrient loss and water runoff from paddocks is actually quite simple, but it takes a substantial investment to install," he said.
A similar system has been used at another Massey farm for several years, focussing on the effectiveness of plantain to reduce nitrate leaching.
"We are just excited to get out there and use it. There are a lot us ready to test ideas we've long theorised. I have no doubt that it will further establish Massey at the forefront of the nutrient loss research in the world under pastoral conditions," said Dr Cranston.
She said other nitrate research was based on theoretical modelling, but this one monitored actual water leaching through the soil.
The study would compare nitrate leaching when sheep graze on either brassica, plantain mix, or a ryegrass/white clover mix.
The systems would all utilise a high stocking rate reflecting an intensive sheep production system.