Young scientists deliver better farming environmental outcomes

14 March 2018

As part of their doctoral studies, a group of bright young women at Lincoln University have helped to find answers to one of the major environmental challenges facing farming by contributing to research into reducing nitrate leaching on farms.

Forages for Reduced Nitrate Leaching (FRNL) is a six-year, $28m primary sector initiative aiming to reduce farming’s environmental footprint by improving the nitrogen efficiency of the animals and plants used on New Zealand farms.

Dairy, arable (crop) and sheep and beef farms are involved in the programme which is focusing on three areas, alternative pasture species, crops, and farm systems.

The PhD students, Kirsty Martin, Anna Carlton, Roshean Woods, Lisa Box, Elena Minnee, and Grace Cun, joined a team of scientists from AgResearch, DairyNZ, Foundation for Arable Research, Landcare Research, Lincoln University, and Plant and Food Research investigating which forages will best reduce nitrate losses.

The multi-partner approach is the first of its kind on this scale in New Zealand where several organisations are working together seeking answers to improve environmental and economic sustainability.

DairyNZ senior scientist Ina Pinxterhuis, who leads the FRNL project, says that the doctoral students have provided valuable information about what is happening at urine patch level.

“When we set out with the large FRNL research programme, we intended to recruit several PhD students. Having these dedicated students researching specific aspects of diverse pasture species is invaluable. They have the time to delve in the literature, do detailed measurements, and develop a solid thesis describing their results and discussing the potential benefits to agriculture. We have been extremely lucky to find these six students. They have engaged well in the programme and even delivered papers and conference presentations on the way.”

Lincoln University’s professor of soil science, Dr Keith Cameron, says the application of science is important to the university, along with its relevance to the agricultural industry.

“At Lincoln we are keen to focus our research in areas where students can see how what they are doing fits into the bigger context, particularly the application of science and the connection between scientific discovery and industry application.”

“The multi-disciplined, multi-partner approach to find answers in projects like Forages for Reduced Nitrate Leaching is the way of the future. When the students leave here they will not only have new skills, but will also have contributed to the research. Many of the students we train at PhD level go on to make major contributions to New Zealand agriculture,” says Professor Cameron.

FRNL is principally funded by the Ministry of Business, Innovation and Employment, with additional funding from programme partners DairyNZ, AgResearch, Plant & Food Research, Lincoln University, Foundation for Arable Research and Landcare Research. The programme finishes in 2019.


Based at the Lincoln University research dairy farm, Kirsty Martin is researching the response to nitrogen of 12 different pasture forages. Her interest in farming began in rural England where she was brought up. Her family moved to New Zealand when she was 14 and a stint on a dairy farm in the school holidays made her decide that an agricultural science degree was a good career option.

She has been monitoring plant responses to different levels of nitrogen applied as fertiliser to identify whether some are more efficient at utilising nitrogen than others. More nitrogen efficient pastures may lead to lower nitrogen inputs into the farm system and less risk of nitrate leaching.

“I enjoy all aspects of my PhD study, particularly because of the variety in everything I do. I can be out in the paddock in the morning shifting the irrigator or taking samples, and in the afternoon in the lab, weighing or grinding them and then on the computer writing up the information,” says Kirsty.

Kirsty, now in the last stages of her PhD, said she is glad all her hard work is being used to make an impact on farmers to reduce their environmental footprint and wouldn’t have taken the three-year journey if it wasn’t useful to the industry. Once finished she will go on to work for a farm consulting company as an environmental consultant based out of Darfield.

“Taking on this three-year journey has been amazing. I now have the experience and knowledge to understand the challenges farmers face with their environmental issues, and it’s my job to give them advice and assistance with the management and practical aspects of the solutions.”

Grace Cun was born in California. At high school she became actively involved in the Future Farmers of America organisation and developed a passion for agriculture. She studied animal science and management at the University of California Davis which deepened her interest in research, dairy cows and forages. This was followed by a Master’s degree in plant science at the California State University Fresno before she came to New Zealand in 2015 to pursue her PhD studies at Lincoln University in Canterbury where she now lives.

“New Zealand has always been renowned for its low cost pasture-based dairy farming systems. I knew heading overseas and studying at Lincoln University would allow me to bridge the gap between abstract principles and real world challenges,” says Grace.

“Research, especially with the FRNL group, has such a practical aspect to it. It involves collaboration across disciplines (animals, plants, soil), and you meet such interesting people. I also love that the academia world of Lincoln University works across sectors with DairyNZ, Ministry of Business Innovation and Employment and others.

“I hope that my research will make a difference and be applicable to dairy farm grazing systems and the environment.”

Bay of Plenty

Anna Carlton didn’t know what she wanted to do at school but loved animals and the outdoors. A visit to a Lincoln University open day from her Tauranga home helped her to decide that was where she wanted to be. A Bachelor of Science degree gave her a taste of everything, animals, plants, soils, and biology. Anna particularly enjoyed the environmental science papers and this is something she has pursued in her post graduate studies.

Her PhD is studying irrigation management and how it affects nitrate loss. Anna is looking at the bigger picture combining animal, plant and soil science. The aim of the research is to increase knowledge and understanding of the effects diverse pasture species and optimum irrigation have on nitrate leaching from grazed pasture.

On the Lincoln University research dairy farm, Anna has used 40 instruments called lysimeters to measure yield, plant nitrogen uptake, N leaching loss, 15N recovery, root distribution and the effect of irrigation type on nitrate leaching, especially over the summer months if not enough water is applied.

In a second lysimeter experiment, Anna investigated the effect of diverse perennial ryegrass and white clover pastures containing plantain and irrigation type on nitrogen leaching losses from cow urine patches.

She hopes this research will enable New Zealand dairy farmers to continue farming in a profitable and environmentally sound way, particularly under the new limit setting regulations being implemented by regional councils.

“It’s a balancing act between the environment and farming profitability. What I enjoyed most about the FRNL project, was the range of disciplines the project covered; the variety made it interesting,” says Anna who has now completed her PhD and is working as a consultant helping to show farmers the practical applications of the FRNL research project.


Enjoying science at school and a school visit by DairyNZ to talk about careers in the industry made Roshean Woods of Timaru realise that the challenge of applying science to help farmers reduce their environmental footprint had excellent potential as a future job option.

“The challenge is that there are a vast number of pasture species but we are limited in our ability to test them all, so we have to choose a selection which we hypothesise will have good potential. Nitrate leaching experiments are costly and time consuming.”

“What I enjoy most about the research is the systematic approach to investigate the use of different pasture species and how they interact with the soil to solve an environmental issue. My days include a combination of office, field, and lab work, which keeps me motivated and interested. I am constantly gaining knowledge and learning new skills along the way.”


Lisa Box and Elena Minnee are both from Waikato farming backgrounds.

Lisa grew up on a dairy farm in the Waikato and loved everything about it. She planned to be a vet but a visit to the Lincoln University stand at Fieldays saw her enrolling for an agricultural science degree.

“I never thought I would want to do postgraduate studies, but I soon became passionate about science, particularly plant science,” says Lisa.

“I enjoy all aspects of my PhD, especially since it’s so topical and closely linked with the dairy industry. It is important for me to be doing something in the science field that is relevant to farming.”

“Nitrate leaching is something that needs to be addressed to improve the sustainability of dairying and it’s important to consider how we go about mitigating it. We need the ability to use the outdoor pasture systems to retain our competitive advantage, and this is where the theme for my PhD came from – using an alternative species to perennial ryegrass.”

Lisa says she likes the variety each day brings.

“I can be on the farm cutting pasture one day and in the office or meeting people the next. I enjoy being my own boss which gives me the ability to organise my time. I might work long hours one month and be free the next. This means I can fit in travel from time to time. Last year I went to India for a month and drove a tuktuk the length of the country.”

Elena Minnee’s parents and grandparents were dairy farmers. Despite this background, Elena wasn’t very involved in farm life except for feeding the calves, so her parents were surprised when she ended up in dairy research.

She was influenced in her scientific career by her biology and chemistry teachers at Thames High School who made subjects fascinating and engaging. Then at Waikato University she enjoyed the discovery part of science and how finding out about one thing often led to other lines of enquiry.

For her PhD, Elena is studying grazed forages. She explains that there is already some research that suggests that protein in various feeds differs in its nitrogen use efficiency which in turn influences the rate of nitrate leaching.

“Some forages release protein earlier than others, so we are thinking that if a cow releases protein earlier, say when chewing, it floods into the cow’s stomach and can’t be digested efficiently.”

“The first step in my research is looking at how different feeds are ingested and then how we can manipulate the outcome by changing fertiliser and grazing patterns to reduce nitrogen excretion.”

‘We know that plantain reduces urinary N concentration and once we understand why, we will be able to screen other forages to see if they share the same characteristics. Ultimately this will lead to better environmental outcomes.”

Elena Minnee

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