Anna Gomes: Agricultural Soil Science in the Lab and the Field

Research Institute Work

My GRIP experience started when I arrived at the Düsseldorf airport on Saturday, May 1st exhausted, but thrilled to finally be in Germany! Quickly running to catch the bus into the city, I eventually got off and wandered down the small village streets until I found my Bed and Breakfast for the evening. The next morning I woke up at 5am and I enjoyed a nice German breakfast of cheese, tomatoes, cucumber, fresh bread rolls, a hard-boiled egg, and some piping-hot coffee. Lesson one, German bread is super delicious! Then I was off to find my way to the small city of Jülich where the research center is located and where I would be staying for the first eight weeks of GRIP. Located in a rural area of western Germany along the Rur River Valley, Jülich is known today for the research center founded in 1956. The first week of my time in Germany was filled with getting a SIM card and a bike, having laboratory and general institute orientation, and meeting the research group. It has been fascinating to learn not only the technical field and lab work skills of agricultural soil research, but also about the work culture of PhD life and the differences in how their research group interacts and operates compared to mine at Stanford.

A few specific examples of PhD culture at the German research institute include: the temporal and spatial separation of work and social time, being considered more of an employee than a University ‘student’, and the lack of teaching duties, as PhD students are mainly focused on research starting their first day. Another main difference is that as a PhD student you are hired directly onto a project which your PI has already received funding for, either through a state, national, or EU funding program. Within the overall research objectives there is some flexibility, however, your work is more directed and hence is typically completed within three or four years. This work plan can allow you to develop more technical skills, but might restrict your independence as a researcher. It was very interesting and useful to witness the differences between the German Institute and Stanford University. These included the student- advisor relationship, experimental design and planning protocols, soil sample collection, preparation, and analysis, along with the general collaboration amongst PhD students within the research group.

Traveling & Arriving at Jülich Research Centre!

A central aspect of my research internship was to learn and perform several field and laboratory techniques that I will utilize back at Stanford for my dissertation research. From shadowing several different research group members over the duration of my summer internship I conducted field tasks: static chamber soil GHG measurements, continuous flow soil GHG measurements, and collecting soil samples (0-90cm), both for standard chemical extractions and bulk soil for my incubation experiment. For laboratory tasks, I was taught how to air dry and oven dry soil samples, measure the moisture content, determine 100% water holding capacity (WHC), calculate the quantity of water needed to reach a specific WHC, measure soil pH and bulk density, prepare soil for nutrient extraction including plant available and total soil nitrogen, dissolved organic carbon and microbial biomass carbon (using the fumigation method).

As part of the field work, I had the opportunity to use the Stenon Farm Lab Tool at one of the field sites. Initially the plan was to take FarmLab Tool measurements and also take soil samples from the same plots, conduct traditional mineral nitrogen extractions in the laboratory and then compare the results to the FarmLab tool. However, two of the three days that I attempted to measure the soil with the FarmLab tool, several error messages prevented me from using the tool. Only on the third time trying the tool did it work, and this was due to the adequate soil moisture present from the recent rain event. The plan moving forward is to wait until the Stenon team has calibrated the FarmLab tool for the soils of California’s Salinas or Central Valley and then collaborate with them on a research project next year. This project would explore the use of the tool to understand in situ nitrogen mineralization dynamics from a combined application of organic fertilizer with synthetic nitrogen directly in the agricultural fields of my research sites.

The second aspect would aim to identify a relationship between the soil mineral nitrogen levels as measured by the FarmLab tool and soil nitrous oxide emissions. These soil emissions are mainly correlated with excess soil nitrogen in combination with specific water and oxygen conditions of the soil.

The final portion of my time in Jülich was spent preparing, conducting, and analyzing my own soil incubation experiment. This was a ‘pre’ experiment to learn the methods and prepare for the full experiment that I will start as soon as I return to Stanford. I was testing the relationship between compost application quantity and soil nitrogen and carbon mineralization dynamics. The soil was collected from a mining reclamation site, adjusted to the proper moisture content, mixed with compost, and packed to a specific bulk density into these tubes which were kept in an incubator. Destructive soil sampling plus continuous gas flow GHG analysis was measured throughout the experiment. I am still awaiting the laboratory results from the research institute, and I am working on writing up the experimental report and discussing publishing this data with a few of my colleagues at the Jülich Research Center. Beyond this experiment, one colleague and I are still discussing the possibility of him sending co-composted bichar to Stanford so that I could analyze this to understand the mechanisms of nutrient absorption and retention as part of an ongoing project happening in Jülich.

Working in the field and laboratory at the Jülich Research Institute!

German Culture

In order to live abroad, one must have a spirit of adventure and the ability to laugh at the many strange situations that can arise. As an example of this, during my first day at the Research Center, I attempted to make a coffee using the espresso maker in the kitchen. Of course I am used to only making American filter coffee, and as soon as I pressed the ‘steamed milk’ button, hot steam (along with my freshly brewed espresso) started to spray everywhere and I quickly cleaned it up before anyone noticed. As another example, the first weekend in Jülich I went to a beer garden near my Airbnb and I had not yet realized that many places did not accept a credit card and I was without cash. My final story consists of me thinking that “bike frei” means ‘bike free’ as in ‘area free of bikes’. However after several days biking on the main road I was informed by a loud yelling German man (in German of course) that I could not bike there.

Although traditional German food is not the most vegetarian friendly, I was determined to try all of the options and I even enjoyed a nice vegan schnitzel. A few of my favorites are spatzel with a mushroom cream sauce, pickled veggie salad with cream dill sauce, flammkuchen, and many of the cakes from the never ending backeris. A few general cultural observations from my time in Germany include the incredible system of non-car transportation options- bike networks, trams, buses, trains, and boats, in addition to the cash payment culture, the German’s impressive knowledge and awareness of US and international politics, and the realization that everyone is very critical of their own country’s leaders and institutional services.

Weekend Exploring

During my first week in Jülich I decided to make a travel bucket list and set off exploring neighboring cities and countrysides. Since I was located in north-western Germany, I was close enough to The Netherlands that I could include some cities there in my plans.

My list of explorations included:

Cologne, Germany; -Koblenz, Germany;
Rudesheim am Rhein, Germany;
Utrecht, Netherlands;
Lemuirs, Netherlands;
Maastricht, Netherlands

I took several guided city tours, ran several miles throughout the streets, and spent many weekends simply walking around these cities taking in the beautiful views, learning some local history, and tasting delicious food.

Adventuring & Exploring!

The final two weeks of GRIP were spent in the beautiful city of Potsdam at the German start-up company Stenon, working with their Soils and Agrisphere team. This allowed me to experience ‘life as a scientist’ inside a private company. Bridging the scientific questions we were working on in Jülich with the practical business of trying to comply with German policies, economic expectations, and basic farmer use, being at the company provided many insights. This technology could transform the way in which we measure, understand, and track changes to the carbon and nitrogen dynamics of our agricultural soils. Currently Stenon is working to be credited by the DüV (German government subsidy program) as an official residual soil nitrogen measurement option for farmers, which would replace the traditional method of sending a soil sample off to a laboratory.

They are currently working with a few farms in California and I look forward to collaborating with them in the future.

Compared to being in academia, my experience working at a private start-up company was filled with quickly shifting tasks and focus points, and a need to produce a working product that can sell as opposed to research for the sake of expanding knowledge. Additionally, German work culture generally moved at a slower pace than California and the management was very careful not to overwork their employees, ensuring break time and adequate compensation.

Following this experience, I am left with the following questions and reflections which I will carry forward into my dissertation research at Stanford:

How do we use soil nitrogen data (both in-situ and laboratory analyzed) to improve soil management practices and reduce excess nitrogen causing both environmental and climate problems?
Which stakeholder group should be measuring/reporting soil nitrogen? Who should pay?
Who should set the standards for soil data collection and analysis? What should the standards be? What data should be collected and how frequently?
What is the spatial and temporal nature of soil nitrogen dynamics?
How fast does mineral N change form in the field? and under what conditions?
How long are the N measurements (both in-situ and laboratory analyzed) valid for?
How can this data be used to inform our fertilizer application decisions?
Should we be taking a budgeting approach to determine the quantity of nitrogen fertilizer to use? Can we better utilize dynamic models and simulations?
Are the crop growth and nitrogen uptake curves that are currently used to determine nitrogen demands too general?
Are we accounting for the interaction between various forms of nitrogen in the soil?
What environmental data is critical to collect in parallel to soil mineral N values?
What is the best use of the data once it is collected? How should it be analyzed?
How do we align the collection of soil nitrogen data with the objectives of the farmer?

My stay in Potsdam consisted of living with a wonderful German host family, which added to the cultural immersion that I was looking to experience while there. It was interesting to observe their family dynamics, household patterns, and even cooking habits. I was very fortunate to have found Jülich and Professor Nicolas Brüggemann’s Research Group as the host for my GRIP experience. This ‘Disneyland for soil scientists’ was an incredible learning opportunity, both in technical research skills including field work, laboratory work, and data analysis, in addition to several cultural lessons including the experience of living in Germany, trying to speak German, meeting several local people, tasting delicious food, and exploring beautiful landscapes. Thank you so much to the Stanford Club of Germany, and the GRIP support team for the financial assistance, and thank you especially to Antonia Fore for the phenomenal guidance and assistance throughout and beyond this journey!