Tessa Schmidt 2


Student Scholarship recipient,

Continuing research into the field of catch crops as a way to reduce nitrate leaching—an indirect source of the greenhouse gas nitrous oxide—is definitely warranted.

That is the view of NZAGRC Student Scholarship Fund recipient Tessa Schmidt, whose work at Lincoln University on the measurement and mitigations of nitrogen losses from winter-grazed forage crops has convinced her that there is a future in researching the subject further.

“The results of my research and previous research on the same trial site by Connor Edwards both indicate there is no significant difference between using a catch crop or maintaining fallow ground.

Tessa’s interest in the science behind the dairy industry came from growing up on a Southland dairy farm.

“My passion for agriculture began during high school after attending a SIDE conference and seeing real benefits of the science behind farming and huge potential for opportunity. I was initially interested in the animal science side, however my interests gradually shifted towards soil science and effective methods to reduce nitrate leaching, using approaches which were easily able to be integrated into the farming system.

“It encouraged my long-term goal of improving dairy farming from an environmental perspective, through plant species, soil, and animal nutrition,” she says.

A Bachelor of Agricultural Science Honours student, in her second year Tessa took a paper based around Farm Environment Plans.

“This course challenged our thinking and helped us to practically understand the challenges farmers may be facing in terms of the environmental space. I began to focus my studies around effective mitigation methods to reduce nitrate leaching which were easily integrated into farming systems; i.e. nitrification inhibitors, the use of diverse pastures and the use of catch crops to uptake residual nitrate in the soil before it is leached from the root zone.”

Her research project at Lincoln University was supervised by Professors Keith Cameron and Hong Di, and conducted in collaboration with Dr Brendon Malcolm of Plant & Food Research.

A large field experiment was designed to determine the effect of using a catch crop of oats, the hypothesis being that the oats will take up nitrate and water, thus reducing the amount of nitrate lost in drainage.

The experiment was conducted using the new SCALAR system (Suction Cup and Lysimeter Array System) based at the Ashley Dean Research and Development Station. This system has 64 suction cups, placed at five-metre intervals, installed at 700 mm (below the rooting depth).

Tessa says the support of NZAGRC has been hugely beneficial to her research—“I would like to acknowledge the support for my project. Learning from Keith Cameron and discussing how and why processes were occurring made for a very interesting project, and this would not have been achievable without the support of NZAGRC.”

Tessa has recently taken a job with DairyNZ as a Graduate Catchment Engagement Leader within the Southland region. This role works with a range of people involved with the dairy sector and helps farmers to understand the policies coming through and what they will need to do to implement the new regulations into their farming system.

“I will also be involved with helping farmers to reach and enhance their good management practices, as well as a range of other commitments. In time, I hope to be able to advocate the new research and development in agriculture to farmers. There are no present plans for further research however, never say never!” she says.