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Selwyn Times: June 14, 2016

34 Tuesday

34 Tuesday June 14 2016 SELWYN RURAL LIFE Research results raise further questions for Lincoln student UnexPeCted and conflicting results from research around irrigation practices and their influence on greenhouse gas emissions have lincoln University Phd student Jen Owens contemplating a more complex scenario and a few possible explanations. Ms Owens carried out a field experiment on a commercial dairy farm measuring nitrous oxide emissions and soil oxygen concentrations under urine patches subjected to varying rates of irrigation. Her studies are integrated with a three-year research programme by landcare research into greenhouse gas emissions from intensive dairying. nitrous oxide is a potent greenhouse gas linked to climate change. Most of new zealand’s nitrous oxide emissions come from grazed pastures where soil is affected by nitrogen inputs such as ruminant urine. nitrous oxide emissions from urine patches are a problem for new zealand given the intensification of dairying. “While many dairy farms are using irrigation to improve pasture production to meet the nutritional needs of their cows, little is known about what happens to the nitrous oxide emissions from urine patches when they are irrigated,” Ms Owens says. Her field experiment explored the possibility that irrigation may modify soil oxygen concentrations, potentially reducing nitrous oxide emissions from urine patches. She found that soil oxygen concentrations under a more frequently irrigated urine patch were lower when compared to a less frequent irrigation regime. These lower soil oxygen concentrations were expected to lead to lower nitrous oxide emissions. However, this didn’t happen, suggesting a more complex scenario. “nitrous oxide emissions were not affected by irrigation frequency but we were surprised to find the more frequent irrigation rate lead to potentially greater nitrous oxide uptake by microbes. These two results appear to conflict with each other. a possible explanation for this is that the potential for the production of nitrous oxide has increased in response to lower soil oxygen, as well as the potential for soil microbes to consume nitrous oxide. So in effect we are measuring the net effect of these two processes.” Based on the results from the study, funded by landcare research, Ms Owens has performed a number of smaller experiments under controlled conditions to better understand how soil biology is driven by the soil’s physical status. “These experiments have helped us interpret how irrigation influences nitrous oxide emissions from urine patches. “We’ve also started looking at urine patch induced nitrous oxide emissions on other soil types and during different times of the year, winter instead of summer, to validate and further explore the impact of soil oxygen concentrations.” Jen Owens [Edition datE] SELWYN TIMES 3 Ms Owens carried out a field experiment on a commercial dairy farm measuring nitrous oxide emissions and soil oxygen concentrations under urine patches. Selwyn Auto Corner Main South Rd and Barters Rd, Templeton. Ph: 3440331 ALL YOUR MOTORING NEEDS › WOF’s › Wheel Alignments › Diagnostics › Repairs › Servicing › Batteries › Tyres Phone 329 5841 | 132 Leeston Road, Springston www.selwynauto.com | office@selwynauto.com

4 SELWYN RURAL LIFE Research results raise further questions for Lincoln student PrOFeSSOr leO Condron has been the UnexPeCted University of and conflicting results Canterbury. from research The around irrigation practices award and their recognises influence his on greenhouse gas extensive emissions contribution have lincoln University Phd to research on the biogeochemistry student Jen Owens of contemplating a more phosphorus complex scenario in soil-anplant explanations. systems. a few possible Professor Ms Owens Condron, carried out a field experiment a Professor of Biogeochemistry on a commercial at dairy farm measuring lincoln nitrous oxide University emissions and soil oxygen and concentrations Senior research under urine patches Scientist subjected in to the varying rates of irrigation. Her Bio-Protection research Centre, has spent 34 studies years are researching integrated phosphorus, with a three-year a nonrenewable research programme resource that by is landcare key to determining research ecosystem into greenhouse productivity. gas emissions from intensive His work dairying. has improved understanding of the role and function of phosphorus in both nitrous oxide is a potent greenhouse natural and managed ecosystems. The award recognises gas linked to his climate outstanding change. contribution Most of new to this zealand’s field of nitrous research oxide with emissions more than come 90 peer reviewed from grazed publications pastures where and an soil international is affected network by nitrogen of collaborators. inputs such as ruminant urine. during his career, Prof Condron has nitrous developed oxide methods emissions for from measuring urine patches phosphorus are a problem levels for new and bioavailability zealand given in the soils. intensification He has also of studied dairying. the impact of land management “While many and dairy land farms use change are using on soil phosphorus in new zealand, and the effects of irrigation long-term to improve forest development pasture production on soil phosphorus. to meet the nutritional needs of their cows, little is known about what happens to the nitrous oxide emissions from urine patches when they are irrigated,” Ms Owens says. Her field experiment explored the possibility that irrigation may modify soil oxygen concentrations, potentially reducing nitrous oxide emissions from urine patches. She found that soil oxygen concentrations under a more frequently irrigated urine patch were lower when compared to a less frequent irrigation regime. These lower soil oxygen concentrations were expected to lead to lower nitrous oxide emissions. However, this didn’t happen, suggesting a more complex scenario. “nitrous oxide emissions were not affected by irrigation frequency but we were surprised to find the more frequent irrigation rate lead to potentially greater nitrous oxide uptake by microbes. These two More recently, his work on recovering and results appear to conflict with each other. recycling existing phosphorus addresses a worldwide a possible concern explanation that finite for this reserves is that of the non-renewable potential for phosphate the production rock are of being nitrous oxide steadily has exhausted increased as in demand response continues to lower to soil increase. oxygen, as well as the potential for soil The doctor of Science degree is of a higher microbes standing than to consume either a Master’s nitrous oxide. degree So or in the effect degree we of are doctor measuring of Philosophy the net (Phd), effect of and these is awarded two processes.” for work that makes an original, substantial Based on and the distinguished results from the contribution study, to knowledge in a field with which the candidate funded is concerned. by landcare research, Ms Owens has The performed degree is a awarded number for of smaller published experiments work of an exceptional under controlled standard, conditions containing to better innovative understand contributions how soil to the biology advancement is driven of knowledge and learning which has given by the soil’s physical status. their “These chosen experiments research field. have helped us interpret how irrigation influences nitrous oxide emissions from urine patches. “We’ve also started looking at urine patch induced nitrous oxide emissions on other soil types and during different times of the year, winter instead of summer, to validate and further explore the impact of soil oxygen concentrations.” [Edition datE] 3 SELWYN TIMES [Edition datE] Tuesday June 14 2016 35 Lincoln University Professor awarded Doctor of Science awarded a doctor of Science from the candidate international distinction in Fungal experts gather information for publication SOMe OF the world’s leading experts in fungal biology and the study of pest and weed invasions met recently at a workshop organised by researchers from the Bio-Protection research Centre. The aim of the workshop, the first of its kind in new zealand, was to stimulate discussion between scientists from different disciplines and develop a publication to guide future research in this area. Sponsored by the new Phytologist trust the event attracted more than 70 scientists for a day of public talks and a four day writing workshop for key participants. Fungi have long been recognised for their diversity of colour and shape, from mushrooms to moulds and mildews, and for their important roles in ecosystems. There is also widespread recognition of the damage caused by non-native fungal pathogens to industries and native plant species. More recently, researchers are also recognising the important roles fungi can Jen play Owens in the spread of other introduced exotic species. in new zealand, for example, pine trees were very difficult to grow, until the introduction of particular species of beneficial fungi allowed them to thrive. These fungi were then eaten by invasive deer and possums and Ms Owens carried out a field experiment on a commercial dairy farm measuring nitrous oxide emissions and soil oxygen concentrations under urine patches. their spores thus dispersed outside of plantations. as a result, wilding pines are now considered the worst invasive weed in new zealand, damaging the environment and becoming expensive to control. “These systems are complex,” says Professor dickie, “but by understanding that complexity we can find new approaches to management. We can also recognise that other introduced plants might be future threats to our environment, depending on whether particular fungal associates are ever introduced.” in early July, Professor dickie will be giving a free public lecture on invasive fungi, plants and animals at lincoln University as part of the Change Makers series. More information is available at www.lincoln.ac.nz/changemakers.