This page is devoted to describing your research through cakes. Clever, edible and fun. Donations welcome and posted here. Soil desserts can also be found on the Soil Science Society of America site. There is now a research cake facebook page, join now!
Removal of bacteria, viruses and ammonium in bioreactors
Femke Rambags completed her PhD thesis which was captured on this cake. It represents her research which focused on the removal of microbial contaminants and alternative nitrogen removal pathways in denitrifying bioreactors The cake has 5 toppings which represent the different media that was tested, on the right you can see bacteria and viruses (jellybeans and flowers) going into the bioreactor and on the front side you can see ammonium and nitrate molecules, which were converted to nitrogen gas by denitrification and anammox.
Otakairangi wetland study
Callum Douglas completed his MSc thesis captured on his researchcake that depicts the vegetation cover across Otakairangi wetland, Northland, which is bisected by a larger drain (blue M&M’s). The marginal swamp belts (which receive nutrients from floodwaters) is characterised by larger vegetation species (flake and chocolate icing). The inner wetland areas (green icing) is mainly dominated by Tangle fern, with the primary peat forming species Empodisma robustum being dispersed primarily on the north side of the drain (yellow M&M’s). The adjacent pot plant is a young Empodisma. To promote recovery of this important wetland, Callum has suggested transplant of Empodisma from the north to the south.
Drainage of peat alters carbon uptake
These cakes summarise a paper by Ratcliffe et al., 2019. Each cake represents a peat bog, with the cake on the left representing Moanatuatua, a peatland deeply drained and the cake on the right representing Kopuatai, an undrained intact peat bog. The cakes were decorated with spun sugar to represent the dominant vegetation Empodisma robustum (wire rush) while the sprigs of Thyme represented the woody shrub Epacris pauciflora. Vegetation at Moanatuatua (left) was taller, and E. pauciflora more abundant reflected by the greater amount of spun sugar and Thyme used. The silver towers represent the Eddy Covariance stations measuring CO2 exchange, with chocolate pieces representing CO2 uptake from the atmosphere with one lump at Moanatuatua representing 69 g C m−2 yr−1 and two lumps at Kopuatai representing 203 g C m−2 yr−1 . Finally to add an authentic peaty aspect to the research cakes a peated whisky was used (Connemara, Kilbegan Distillary, Ireland) to souse each cake. Kopuatai, being the wetter of the two, receiving a more liberal sousing and was slightly more popular.
Modelling non-covalent interaction
Daniel Schipper developed a computer model during a summer research project that allowed calculation of regions of non-covalent interactions between molecules helping understand their chemical properties. The example cake is of bonding between adjacent formic acid monomers, represented by liquorices and jelly beans. The Mentos represents regions of non-covalent bonding defined by region where both the electron density and the reduced density gradient is lower than a cut-off value. Colour of the Mentos describes whether the region is attractive (yellow) or repulsive (purple).
Losses of soil C and N from pastures under irrigation
This research cake was based on Jamie Millar’s Masters thesis. The cake depicts an area of a paddock that is pivot irrigated (semi-circular wheel tracks in brown chocolate) and an adjacent non-irrigated portion of the paddock. The toothpicks show the soil sampling areas. There was a net loss of soil carbon of -5.9 t C/ha and nitrogen of -0.2 tN/ha under irrigation of these Pumice Soils. The cake was sponge representing the Pumice Soil profile with a layer of lemon curd for ash (and other Taupo eruptive events). The A horizon was made from crushed Oreos and iced with butter icing.
Nitrous oxide emissions from Brassicas and ryegrass
This is the researchcake Sheree Balvert produced on completion of her PhD thesis. It represents her feeling that she came out with more questions than answers… a rather a common experience for PhD students! The cake is split in 2 halves where nitrous oxide emissions (crispy noodles) from two forage types (green coconut vs spearmint leaves representing ryegrass/clover and brassicas) are compared.
Temperature dependence of soil respiration
This research cake was created by Jasmine Robinson to represent her MSc thesis and subsequent paper on the temperature dependence of soil respiration. For her thesis she used a large aluminium block, heated at one end and cooled at the other, to incubate soils and measure respired CO2 along a stable temperature gradient (~2 – 50°C). Her cake was made using 6 delicious chocolate cakes, chocolate buttercream icing and a truck load of fondant! Also green jelly coolant. Check out the paper:
Plus and minus
Louis wrote a letter to the editor expressing some concerns about a paper published in Global Change Biology that examined changes in soil carbon stocks following deforestation. The authors of the original paper responded with their views. A critical component of research and development of ideas is the debate. This #Researchcake recognises that there are arguments for (pluses) and against (minuses) all ideas, particularly new ideas, and there is great value in the discussion. It is important to understand that these debates are not personal but trying to advance our understanding. P.S. this is possibly the laziest researchcake made from store-bought Lamingtons.
Cadmium crossword – 3 papers in 1 PhD
Globally convergent leaf respiration?
This research cake by Liyin represents a publication of the temperature response of leaf respiration rates from around the globe. The Chinese mooncakes that sit under each leaf are round mitochondria that power respiration. Inside the mitochondria, the high concentration of proteins (solid custard made by mike powder and eggs) are the enzymes that regulate leaf respiration. The cakes are identical in appearance because we showed very similar thermodynamic properties of the collective enzymes that drive leaf respiration around the globe whether collected from the arctic or the tropics. http://onlinelibrary.wiley.com/doi/10.1111/gcb.13936/full
Reducing nitrous oxide emissions
Sheree’s cake summarises a recent published paper from her PhD looking at whether secondary metabolites found in brassica crops can decrease nitrous oxide emissions from cow urine applied to soils. Nitrous oxide is a potent greenhouse gas and there is a great deal of interest in finding ways to decrease these emissions.
The left of the cake represents soil amended with these secondary metabolites (glucosinolate hydrolysis products) where the molecular structures of some of the compounds are drawn with white icing, and the right side is control soil. The length of the vertical noodles represent the nitrous oxide emissions measured from each treatment, short noodles = lower emissions (not to scale). So, overall my laboratory study identified some plant derived compounds that have promise for reducing greenhouse gas emissions from agriculture.
Temperature monitoring in Antarctica
This cake shows the measurement of climate data in the Wright Valley, Antarctica and forms the basis of Annette Carshalton’s Masters thesis. The grey poles represent 5 climate stations distributed up the valley. The red piping under each tower represents the temperature fluctuations.
Annual summer temperature is portrayed by the size of each of the climate towers (smaller being colder). As expected there was an attitudinal trend with colder temperatures on Mt Flemming compared to the temperatures see in the bottom of the Wright Valley on the coast.
4 parts per thousand
New research cake summarising a recent commentary in Nature Climate Change on the 4 per mille initiative. This initiative encourages carbon storage in soil to offset greenhouse gas emissions.
On the left is what 4 per mille looks like: the dark chocolate buttons are soil C and the white buttons are the 4 per mille accumulation, actually it is about two/three years accumulation (hard to weigh out such small amounts). On the lower right is some competing use of residues which are needed to increase soil carbon – fuel for cooking or construction of shelter. Above right is incorporation of residues in soil – hopefully improving soil quality and supporting potentially production.
Paper is here: http://www.nature.com/…/journal/v7/n5/full/nclimate3286.html
What does irrigation do to microbial respiration?
Previous research showed that irrigated grazed pastures had less carbon than adjacent non-irrigated soils but the reason for these differences was not known. This cake represents Olivia Petrie master’s research that investigated the temperature and moisture sensitivity of microbial respiration in irrigated and non-irrigated soils. There were two halves to the cake: the lighter side is buttercake and represents the non-irrigated soil which was generally lighter in colour due to a lower moisture content and the darker side is chocolate cake which represents the irrigated soil which was darker due to higher moisture content. Olivia found that respiration in irrigated soil had a lower overall respiration rate but higher temperature optimum than non-irrigated soil. One possible reason for this was a change in microbial community composition which is represented in this cake by the different sprinkles on each treatment.
Twin papers on carbon storage
This cake summarises two papers that tried to find out if converting our traditional ryegrass/clover pastures to more diverse pasture swards could increase soil carbon. Each column represents a different treatment applied at the Troughton farm and rows are years. The right column is a control that was under ryegrass clover throughout the three years. The middle column was initially normal pasture, sprayed off (middle row), and renewed back to ryegrass clover. The left column is normal pasture, sprayed off and converted to diverse pastures (including species like plantain and chicory). M&Ms on each square are worth 250 kg of carbon per hectare and show how carbon stocks changes through the three year study. In the end, converting to diverse swards maintained carbon better than converting back to ryegrass clover. One of the reasons for increased soil carbon storage is greater root inputs of carbon which is shown on the side of the cake.
Peter Lafleur is visiting and made a research cake to eat before his presentation. The cake depicts the shape of the iconic Mer Bleue peat bog, which has been studied for nearly 2 decades with a focus on the exchange of carbon between the atmosphere and the bog. Globally peatlands generally slowly accumulate carbon with time and this is shown on the cake: NEE stands for net ecosystem exchange and DOY is day of year. The three coloured lines are different years and show that the amount of stored carbon varies between years and the reasons for this variability are not really understood but Peter is on the case!
Our summer BSc(tech) students, CJ and Liam have spent the 3 months with us mapping the soils at our research farm. CJ made a wonderful, two layer (A and B horizons) cake using M&Ms to position soils in the landscape. CJ is holding the legend to make sure we remember which soil is which. Meanwhile, Liam has the generated soil map of the site. They also measured a wide range of different soils properties that will be very valuable in our future work.
How many scientists started playing Dungeons and Dragons? Meet two members of Team Orcman.
Norman Taylor Lecturer
Last year at the joint annual conference of the New Zealand and Australia Societies of Soil Science, Louis gave the Norman Taylor lecture titled: “Carbon, nitrogen, energy storage in organic matter of pasture soils – and cake“. Louis is pictured with the physical award – Norman Taylor‘s auger which has been silver plated and mounted on wooden board. Louis made a cake loosely depicting the award.
A cake to celebrate the launch of a book by Megan Balks and her friend Darlene Zabowski – “Celebrating Soil: Discovering Soils and Landscapes”
and also in recognition of World Soils Day.
Root inputs following herbicide
Sam published his second paper from his PhD and despite now working in the South Island, sent us a photo. The cake shows herbicide sprayed, and then regrassed, pasture (on right) vs non sprayed pasture(on left). Roots are shown on side of cake and the amount of carbon input into the soil following spraying depicted with M&Ms around the base. Spraying roughly doubled carbon inputs to soils and so there are about twice as many M&Ms under the regrassed side. Increasing carbon inputs to soil and its stabilisation is critical for removing carbon dioxide from the atmosphere.
McNally, S.R.; Laughlin, D.C.; Rutledge, S.; Dodd, M.B.; Six, J.; Schipper, L.A. (in press) Herbicide application during pasture renewal increases root turnover and carbon input to soil in perennial ryegrass and white clover pasture. Plant and Soil.
Evaporation from pastures
Jack published a paper that measured evaporation rates from three sets of paddocks at the Troughton farm. He found very little variation in evaporation between sites, years, or even following decreases in pasture biomass after grazing, which is shown on the cake by varying amount of green grated coconut. He demonstrated this lack of difference was because radiation was the major controller of evaporation. This consistent water loss is shown on Jack’s cake by equivalent numbers of water molecules (jelly beans) in the three paddocks of Jack’s cake. The fourth brown paddock portrays a “sprayed-off” paddock prior to pasture renewal and had lower evaporative losses and, of course, fewer jelly beans.
Pronger, J.; Campbell, D.I.; Clearwater, M.J.; Rutledge, S.; Wall, M.J.; Schipper, L.A. (2016) Low spatial and inter-annual variability in evaporation from a year round intensively grazed temperate pasture system. Agriculture Ecosystems and Environment. 232:46-58.
Pathogen removal in a denitrifying bioreactor
Femke had paper accepted in the Journal of Environmental Quality where she demonstrated rapid pathogen removal from treated wastewater as it passed through a denitrifying bioreactor (about 20 m long). The inlet is on the left with two sampling ports (blue) and further sampling points along the length of the bed and one at the outlet. The green icing represents sedges growing on top which is pealed back to show the wood chips (nuts). The poster in the background celebrates her success in winning a prize for giving an oral presentation of her work.
But wait, there’s more! Femke is getting married in Nepal soon and the two dolls represent are her and Ilias (her hubby-to-be). Safe travels!
Rambags, F.; Tanner, C.C.; Stott, R.; Schipper, L.A. (2016) Fecal bacteria, bacteriophage, and nutrient reductions in a full-scale denitrifying woodchip bioreactor. Journal of Environmental Quality. 45:847-854. doi:10.2134/jeq2015.06.0326
Adrea’s MSc Thesis examined the rate of soil recovery on four landslip zones (shear, intact accumulation, transition and re-deposition) with adjacent control zone to represent soil pre-landsliding. She concluded that differences between landslide zones were greater than differences between landslides of varying ages for C, N, and P. Her multi-layer cake represents one of the many landslides she sampled.
Persian dessert to finish off pizza lunch
Mahdiyeh Salmanzadeh brought in a Persian dessert called Halva which include flour, sugar, saffron and rose water made by her mother who is visiting. This was an excellent sweet for our end-of-semester celebration pizza lunch.
Doreen celebrates her PhD thesis submission
Doreen recently submitted her PhD thesis in which she studied carbon and DNA preservation in buried allophanic soils and paleosols on Holocene tephras in New Zealand. Allophane in such soils can encapsulate organic matter and DNA and the once-surface horizons became increasingly divorced from the modern organic carbon cycle with time because of the ongoing tephra deposition. Buried deep in the layers of her cake are red allophanic spheres with sorbed organic matter and DNA. On one of her sampling sites where existing vegetation is mainly European grasses, Doreen isolated DNA fragments of New Zealand native trees from the 2.2 m-depth horizon (c. 5500 to 9400 years old).
Urine spotting cake
Olivia Jordan (a former Masters student at Waiber) has recently been working as a casual research assistant at AgResearch. Work has included considerable amounts of urine spotting and leachate collections with associated lab processing. Upon leaving AgR for a position at DairyNZ she thought she would make a urine spotting cake! Both sheep and cows are represented as are little yellow patches, not so easy to see in the field.
Olivia will be working as a Assistant Research Technician at DairyNZ, they will be lucky to have baking skills!
Carbon balance of a dairy farm
Susanna Rutledge published a paper that looked at the carbon balance of a dairy grazed pasture at Scott Farm over four years. Depicted on the cake is the average carbon inputs and outputs in units of jellybeans (jb), where 1 jb = 200 kgC/ha.y. Inputs (right side) include imported feed, effluent and the net of carbon dioxide exchange. Outputs include milk export, silage and methane. The balance (3 jelly beans) is assumed stored in soil.
S. Rutledge, P.L. Mudge, D.I. Campbell, S.L. Woodward, J.P. Goodrich, A. M. Wall, M.U.F. Kirschbaum, L.A. Schipper, 2015. Carbon balance of an intensively grazed temperate dairy pasture over four years. Agriculture, Ecosystems and Environment, 206, 10-20
Megan Balks, with co-author Prof Darlene Zabowski of University of Washington and support from graphic designer Marianne Coleman, recently got her book, provisionally titled “Celebrating Soil” submitted to Springer Publishers. The richly-illustrated, popular science book celebrates the soils and landscapes on Earth, ranging from the Arctic to the Antarctic.
Increased roots below diverse pasture
Sam McNally (PhD candidate) had his first paper accepted which compared root biomass of ryegrass/clover and more diverse pastures (including plantain, chicory, and lucerne). He found greater root biomass in the more diverse pastures which also had deeper rooting. The hypothesis is then posed that this greater biomass will increase carbon inputs and potentially storage in soil.
On Sam’s cake, the diverse pasture is on the left and you can see greater rooting depth and biomass down the side. Lego man is taking cores on either side of the wooden fence.
McNally, S.R.; Laughlin, D.C.; Rutledge, S.; Dodd, M.B.; Six, J.; Schipper, L.A. (2015) Root carbon inputs under moderately diverse sward and conventional ryegrass-clover pasture: implications for soil carbon sequestration. Plant and Soil. 392: 289-299.
Emma finished her MSc thesis which attempted to determine reasons for pasture pulling. Pulling occurs when animals grazing on pastures and pull the whole plant out of the ground rather than only removing leaf material. Emma attributed pulling to limited rooting depth, low root density in the 5-10 cm depth, increased compaction with depth, less cohesive soil when it has low moisture, and the incidence of pasture growing in clumps. Emma made cup cakes with little pasture clumps – these were completely grazed.
Root stocks in pasture swards
Olivia finished her MSc thesis which looked at seasonal changes in root biomass in 14 pasture sward mixes (3 replicates each). 2,500(!) cores (taken to 60 cm) later, the observed root biomass ranged from 1100-24000 kg DM ha-1 across the different mixtures. From seasonal sampling, total carbon input to soil ranged from 700 to 1300 kg C ha-1 y-1. Olivia’s cake displays soil cores laid out with topsoil at left and gleyed soil horizons to right. In the end, Olivia sampled and washed more than a m-3 of soil.
Global soil 15N measurement
Louis contributed to a paper synthesising global distribution of soil 15N led by Joe Craine (Kansas State University). The paper hypothesised new reasons for spatial variation in 15N of soils focusing on the extent to which organic matter has been decomposed. Louis’ cake depicts the sampling sites around the world – New Zealand was nearly completely hidden due to high sampling density.
Patterned ground in Antarctica
Megan Balks and her former student Josh Scarrow published a new paper: Scarrow, J.W., Balks, M.R., Almond, P.C. (2014) Three soil chronosequences in recessional glacial deposits near the polar plateau, in the Central Transantarctic Mountains, Antarctica. Antarctic Science. 26: Pages 573-583.
Megan brought us a cake that provides a delicious example of bouldery desert pavement and patterned ground in Antarctica that forms in deposits of rocks, gravel and sand previously entrained in an advancing glacier. As the glacier melts and retreats the rocks remain on the permafrost surface. Pictured are the cake (the underlying permafrost is represented as frozen cheesecake) and adjacent is a photo of the real thing!
Mahdiyeh Salmanzadeh had her PhD enrollment confirmed and so treated us to an Persian dessert called “Sholeh Zard”. A rice pudding with a really different, lovely flavour of saffron and rose water, topped with cinnamon and almond.
Improved soil carbon measurements
Tim Norris recently submitted his MSc thesis where he tested a new approach for determining the effects of land use on soil carbon stocks. Tim sampled 24 adjacent drystock and dairy farms using a new coring approach. Not only was the method able to detect smaller differences between land uses but was about 2-3 times faster (and easier) than traditional pit sampling. His cake (note: this is the first cake he has ever made!) shows dairy and drystock farms, blue squares on either side of the fence represent sampling plots. The dairy farm is slightly lower than the drystock site because of soil compaction under dairy. If you zoom in, you can also see a deep-burrowing earthworm sweet.
DNA binds to soil
Doreen brought us a cake to celebrate publication of her recent book chapter which looked at how DNA binds to allophanic clays as part of her investigation into finding ancient DNA in buried tephras.
Huang, Y-T.; Lowe, D.J.; Churchman, G.J.; Schipper, L.; Rawlence, N.J.; Cooper, A. (2014) Carbon storage and DNA adsorption in allophanic soils and paleosols. In: Hartemink, A.E.; McSweeney, K. (eds). “Soil Carbon”. Progress in Soil Science Series, Springer, New York, pp. 163-172.
Temperature response of biology
New paper with our colleagues in the Molecular Biology lab led by Vic Arcus and so two cakes were needed.
Schipper, L.A.; Hobbs, J.K.; Rutledge S.; Arcus, V.L. (2014) Thermodynamic theory explains the temperature optima of soil microbial processes and high Q10 values at low temperatures. Global Change Biology. 20, 3578–3586. DOI: 10.1111/gcb.12596.
Vic’s cake, made by his daughter Grace, has the newly modified Arrhenius equation (macro-molecular rate theory – MMRT) that takes into account changes in heat capacity of enzyme-catalysed reactions. This equation predicts a temperature optimum for biological reactions. Louis’ cake depicts changes in Gibbs free energy during a model reaction where a mint is split into two gummy bears.
700 years young
David Lowe led a third year soil science fieldtrip to a tephra section and brought a cake with him for morning tea. This year is the septingentenary cake birthday of the Kaharoa (700 years young). Anna has lined up the tephra layers in the cake and the section.
Peat decline in Waikato
Jack Pronger had a paper accepted in the Journal of Environmental Quality that determined rates of peat subsidence under agriculture in the Waikato. The cake depicts the different landuses: dairy, blueberries, cropping for maize and a remnant restiad peat bog (dark green). Jack used a peat probe to find the bottom of the profile and the little lego man is holding one. Notice also that the remnant bog and blueberries site have slightly higher surface elevation while the maize cropping has a lower elevation. This demonstrates how different land uses are likely to alter subsidence rates.
Pronger, J.; Schipper, L.A.; Hill, R.; Campbell D.I.; McLeod, M. (2014) Subsidence rates of drained agricultural peatlands in New Zealand and the relationship with time since drainage. Journal of Environmental Quality. 43: 1442-1449
Carbon balance of a peat bog
Dave Campbell brought in a cake of a study conducted at Moanatuatua which looked at annual carbon budgets. Featuring a eddy covariance tower, footprint analysis, solar panels, wind turbine and adjacent forest.
Campbell, D.I.; Smith J.; Goodrich, J.P.; Wall, A.; Schipper L.A. (2014) Year-round growing conditions explains large CO2 sink strength in a New Zealand raised peat bog. Agricultural and Forest Meteorology. 192-193:59-68.
50th birthday and education
Surprise birthday (50th!) research cake for Louis from Angela – summarising some of his contributions to soil science education.
- Courtney Ruffell and Staci Boyte worked with us over the summer break on controls of CO2 production from soils and litter. They made this banana cake. Staci examined temperature controls of soil respiration and Courtney investigated photodegradation of plant litter in restiad bogs. The cake is a infrared gas analyser which both of them used to conduct their experiments. In the background is the real analyser
Paired site sampling and carbon stocks
Alice Barnett measured carbon and nitrogen stocks in 25 paired dairy and drystock sites and demonstrated dairy farms have less carbon than drystock in the topsoil. The cake shows the soil pits dug on either side of the fence with M&Ms on the bottom for annoying stones. The paper was published so Louis made a cake.
Barnett, A.L.; Schipper, L.A.; Taylor, A.; Balks, M.R.; Mudge P.L. (2014) Soil C and N contents in a paired survey of dairy and dry stock pastures in New Zealand. Agriculture Ecosystems and Environment. 185: 34– 40.
A beginning in research cakes
Alex and Anna have created a cake of their research projects. On the left, an eddy covariance tower and board walk on a peat bog where Alex’s MSc project is looking at canopy contribution to CO2 flux. On the right, Anna’s MSc project examining temperature sensitivity of nitrate removal in denitrification beds complete with sampling wells. In the background, Nadia looks amused, but probably wants to eat cake.
Note that the ideas/descriptions/opinions on these pages are ours and may not reflect those of the University of Waikato.