News

Seventeen graduate students in the AGRI5700 Graduate Communication course are required to write a news article from our Ruminate/seminar sessions and encouraged to share them with the campus and university community.

Soils, Symposiums and the Struggles of a Graduate Student

Carolyn Wilson
September 17th, 2014
Dalhousie University – Faculty of Agriculture

What do free conference food, soil nitrogen dynamics and curly hair have in common? On September 9th, graduate students in the Ruminate discussion group at Dalhousie University Agricultural Campus caught up with Ph.D. candidate and NSAC/Dalhousie Alumnus Daniel Gillis. The curly-haired Gillis had recently returned from the Complex Soil Systems Conference in Berkeley, California and was eager to share his conference experience. Gillis also discussed his interesting soil-related research and provided key advice for new graduate students.   

The Conference Experience

The Complex Soil Systems Conference was held at the David Brower Centre from September 3rd to 5th and included oral and poster presentations spanning seven soil-related themes. Twenty-minute talks were held in the beautiful Goldman Theatre and were attended by audiences of 150 to 200 people. With over 40 oral presentations in less than three days, the conference was a splendid opportunity for Gillis to hone his talking skills.

Poster presentations at the Complex Soil Systems Conference were held in the Kinzie and the Tamalpais Rooms of the Centre. During poster sessions, conference patrons were free to roam between the two locations to look at the presentations. Poster presenters stayed near their displays so that they were available to answer questions and receive comments from interested patrons. At the conference, Gillis presented a poster on his original research titled: “FLOGing data to link carbon and nitrogen cycling from organic matter additions to agroecosystems.” The poster was immaculate in size and esthetically designed. It was clear that Gillis put years of work, blood, sweat and tears into the research, beginning with the publication of a new model for carbon mineralization in the journal Geoderma in 2011 which he has expanded to describe soil nitrogen dynamics.

Gillis believes that conferences help bring scientists together. Rosalie Madden, chair of the Ruminate discussion group, agrees that conferences are a great networking opportunity: “Everyone [that graduates from project-based M.Sc. program] has a thesis; it is what else you do that sets you apart.”

Meeting with other researchers and graduate students at conferences is an excellent way to share ideas, gain insights and meet new project-collaborators. In particular, Gillis enjoys listening to the individuals whom he has cited in his writing and publications. At the Complex Soil Systems Conference, Gillis was fortunate to see a presentation by Dr. Mary Firestone, a Berkeley researcher studying the role of soil microbial communities in the cycling of soil organic matter.

Microbes, Mineralization and Modelling

During Ruminate, Gillis briefly discussed his research and the model he developed. His model describes the relationship between carbon dioxide release and nitrogen cycling during the microbial breakdown of organic materials, such as compost, in soil. To test the model, Gillis combined data from his own incubation experiments and from the literature for a total of 70 datasets. Among other parameters, the model is able to predict the timing of nitrogen mineralization in soil following the addition of organic material. Unlike it sounds, nitrogen mineralization is not the formation of shiny, metallic nitrogen-rich mineral rocks. Rather, it is an important soil process that occurs when soil organic nitrogen, from plants and organisms, is converted into forms of inorganic nitrogen that are available for plants to absorb. Inorganic nitrogen is a big deal for plant growth, as nitrogen is used to build proteins, chlorophyll, genetic material and other essential molecules.

Predicting organic nitrogen mineralization from soil amendments like manure and compost has important agricultural implications. In a practical sense, if net nitrogen mineralization from soil amendments is occurring in farm soil, it is likely unnecessary for a farmer to apply full rates of nitrogen fertilizer to the field. In other words, there is no need to apply inorganic nitrogen if there is already tons of it in the soil, literally. Soil nitrogen mineralization models, such as Gillis’s, can be used to optimize the timing of fertilizer application to crops. Because this potentially reduces nitrogen losses to the environment and increases cost efficiency, these models will play an important role in the future of sustainable farming.

As a fellow researcher, Gillis’s discussion of mineralization, microbes and modelling captured my attention. For my graduate project, I am comparing compost from different local organic wastes. I want to determine what sources of compost can increase the yield of potatoes and improve the ‘health’ or ‘tilth’of soil. Each of the composts selected for my study have a different nitrogen and carbon content. I am curious: Which compost increases mineral nitrogen in soil? How long after compost application will organic nitrogen be mineralized? Will mineralized nitrogen from compost affect the yield of potatoes? To answer these questions, I need look no further than across campus to Gillis and his original model.

Final Words of Advice

Gillis shared several tidbits of advice for new graduate students and future publishing authors:

1)      When submitting an article, select the journal carefully. Great articles may be rejected, not because of lack of quality, but because they do not fall within a journal’s unique publication criteria.

2)      Go to conferences and network, network, network. Networking is one of the goals of graduate studies (supervisors may need to be reminded of this).

3)      Most importantly, enjoy all the free food and drinks possible. The quality of a conference is often determined by the quality of food.

The Complex Soil Systems Conference in California was a great experience for Daniel Gillis, an eager young Ph.D. candidate at McGill University with Dr. Shiv Prasher and co-supervised by Dr. Gordon Price at Dalhousie University Agricultural Campus. The conference enabled him to interact with prominent researchers in soil science, network with other graduate students and enjoy delicious free food. Whether his work be focused on mineralization, modeling or microbes, I look forward to reading Gillis’s future publications. Perhaps I will be citing his work in my first published article sometime soon. Until then, I will continue to enjoy all the free food I can.