Monthly Archives: October 2015

Química i samba

This week was quiet. On Monday, the titration measurements were still off so after readjusting some things, the measurements on Wednesday were finally consistent. The problem before was due to my embarrassingly poor chemistry skills. Thankfully Joan never makes me feel like an idiot; he might be thinking it, but maybe he knows I feel that way already so no need to mention it! At least I learn from my mistakes and I know I’ll do it right the next time. I can definitely say I’m learning a lot of new skills here. When Joan works out the chemistry calculations with me, he’ll always ask, Am I right? Let me know if I’m doing this wrong. And I’m like, Carry the one….Just kidding. Since he does it all quickly like he’s done it a million times, I’ll usually just go back to my desk and try and follow his steps to get the same numbers at my own pace, so I understand how to do it. I feel, though, that I could get the hang of doing the calculations and learn how to make solutions properly. However, quite a deeper understanding is required to know what reactions are going on when this solution is added to that and why that is happening; in other words, molecules moving around to attach to something else and keep the equation balanced. This stuff I’m sure I did in high school and is pretty basic for anyone studying chemistry, but for me, it all feels so sciency I feel like I’m practically Marie Curie! (I can’t compare, I know.)

While the soils are incubating and now that it’s going well and respiration measurements will be once a week, I have time to do other analyses. So next week I will begin extractions of dissolved organic carbon (C) and mineral nitrogen (N). This is something I did during my Master’s at McGill University. However, that’s as far as I went. Once the extractions were done, we would hand them over to the lab technician who would run it through an auto-analyzer to determine the mineral N, while the organic C was measured on a Total Organic Carbon (TOC) analyzer. Here, however, they don’t have those machines. So after the extractions, I will also be analyzing for mineral N and organic C, all by myself. This requires a few more chemicals and then running samples on a spectrophotometer. There is definitely something to say about automatic machines versus benchtop chemical analysis: one is way quicker and easier than the other. However, doing the chemical analyses by hand forces you to understand all the steps and know what’s going on. In preparation for analysis of total C and N (that will be determined by a machine, thankfully), I started grinding soil samples using an electronic mortar and pestle. It was pretty cool. Other than that it was a pretty quiet week in the lab. Oh, I did get my UB welcome packet this week (a month and a half later, but still)! Along with an English-Catalan/Catalan-English phrasebook, info about the UB and Barcelona, and an agenda, I also received a visiting student card that gives me access to the library, the athletic centre, an email account and wifi. It’s nice to feel I belong to a university community again, that they know I’m here.


Outside of my lab life, I thought I’d leave you with something a little more exciting: photos of my sister playing with her batucada group, Batala Barcelona, last Saturday, a No Car Day in Barcelona. There were a few streets in Barcelona closed off to cars and only for pedestrians and bikes. My sister and her group walked up and down the Via Laietana in downtown Barcelona for an hour, pounding their drums and twirling their sticks in the air while a crowd of people, including myself, followed them taking pictures and filming. It was a lot of fun to watch.

Pont i incubació

Last weekend was puente (long weekend). In Canada Monday, October 12 was Thanksgiving. In the US it was Columbus Day (though I don’t know why the day should be just for him). In some Latin American countries, October 12 is known as Descubrimiento de América or Día de la Raza. In recent years, however, some countries have either changed the name of the holiday (like in Argentina: Día del Respeto a la Diversidad Cultural) or stopped celebrating it as a holiday altogether (like in Paraguay, where instead there are often protests that day by indigenous groups). In Spain October 12 is Día de la Hispanidad, a general, innocuous-sounding title.

Anyway, since it was puente, we had plans for the weekend. On Saturday, Luis and I went to Girona for the day. Girona is about an hour from Barcelona and has a nice preserved medieval city (where, for those who are fans, the latest season of Game of Thrones was filmed). We spent the afternoon strolling through narrow passages, along parts of the old city wall, checking out the cathedral and the old Jewish ghetto. Lunch and a coffee in the plaza in front of the cathedral made for a very nice visit all in all.

On Sunday, Joan had invited us to his family’s country house in the tiny village of Figols de Tremp 3 hours from Barcelona so we headed out in the morning to arrive around noon. The countryside was beautiful as we headed northwest towards the Pyrenees. The mountain ranges in the area would be considered pre-Pyrenees (foothills maybe?) and, if the sky was clear, we could see the Pyrenees in the distance as we wound our way further up the hills. Figols de Tremp was Joan’s mother’s hometown, but as is the case for many small rural villages in Spain in the last decades, most of the people have moved to the cities. In Figols there are only 5 houses and only one older couple lives there year round. The rest are like Joan and his family, coming out only a few times per year. Admiring the view from Joan’s amazing home perched on a hill, Joan pointed out ruins of small abandoned villages, as well as Castell de Mur, a well-preserved medieval castle, and old towers used in medieval times to communicate danger by lighting fires (think Lord of the Rings).

After meeting Joan’s wife, Isabel, and their two teenage kids, as well as family friends also spending the weekend with them, we grabbed some baskets and headed out to a pine forest to look for mushrooms. Joan’s PhD involved working with forest soils so he knows a lot about forest tree species and can identify at least the edible mushrooms. We wandered around the forest for a bit, looking closely at the ground to find good mushrooms, but it seemed others had beaten us to it. We moved a little deeper into the woods and suddenly we hit a spot that was full of fredulics (Tricholoma terreum). We filled our baskets so much we could barely carry them. Isabel told us that normally they don’t collect that many in one outing. We were lucky no one had found that spot and also that the weather this fall has been just right for mushrooms: not too much rain nor wind, not too hot, and not too cold. Back at the house, we set up the table to clean the mushrooms and discard those with worms. As we cleaned, Isabel prepared a delicious dinner featuring mushroom Spanish tortillas. It was fun to be able to say we had scavenged for (part of) our food and then be eating it fresh! (We fully trusted they were edible; so far so good!)

On Monday morning, a group of us led by Joan went for a hike up the mountains to the Castell de Mur. Once again, the walk and the views from the top were fanstastic. We arrived back at the house early afternoon where we had a last meal of sautéed vegetables and fresh mushrooms before driving back to Barcelona. It was really a great weekend with wonderful people and I really appreciated Joan having invited us, it was definitely a very nice gesture.

The rest of my week was devoted to my incubation experiment. I set it up on Tuesday and now it is up and running! On Wednesday I did the first CO2 measurements which involves doing titrations. I have not done this much chemistry since probably high school and I don’t think I even did titrations then. Luckily, Joan is very patient and after showing me how to titrate the first time, it was smooth sailing finishing all the samples. These measurements will give me the respiration rates from the different treatments so we can see how much each biochar-soil combination increases or decreases decomposition. On Friday I did the second CO2 measurements. The measurements this time were a bit strange, so we’ll see how they look on Monday.  After that, as the weeks continue decomposition will slow down so the measurements can be spaced out more.  We’ll see how things look over the next 90 days!

 

Preparació

This week I started preparing my lab experiment. Monday morning Joan and I headed once again to the forest we went to last week, this time to collect soils from two soil horizons, an organic layer and a mineral layer. We arrived back at the university in the early afternoon and I spent the rest of the day sifting the soils to remove leaves and roots and make them as homogenous as possible. The following days the weighing began…oh, saudade for my assistants in Brazil! Two days of weighing soil samples, (staying until 9pm one day when I had hoped those long days in the lab were finally behind me) made me miss our 2, 3 sometimes more assistants with whom I would have gotten everything weighed in 3 hours. After weighing the soils and adding the biochar, I placed the sealed cups in a rotating mixer so that the biochar would mix thoroughly with the soils, and left them overnight.
Samples spinning

The next day it was time to moisten the soils. This again took a few hours, but the automatic pipetter I used was awesome. It was so great to be able to put an exact, precise amount, like 1.8 mL, with just one pipetter and not have to use 3 or 4 different ones to add up like I had to in Brazil, or use less precise glass pipettes.
Awesome pipetter
There are definitely pros and cons to every place you work at. Here, there is a lab technician, Andreu, and he has been super helpful in showing me where things are and how things work. If anything is missing, I can just ask him and he’ll find it or place an order for it. In the labs I worked at in Cuiabá there were unfortunately no technicians so students often had to figure things out on there own, the result being that things were often missing or broken or with a long waiting list. Here, there is no water distiller in the lab, but they have the distilled water delivered to the lab in jugs. There is even an electric pump to pump water into smaller containers for easier use. Amazing! In Cuiabá, the lab I used also didn’t have a distiller so us students had to go to other labs that had distilled water and hope they let us use some. Then we had to lug the jug back to the lab and, in my case, ask a strong student to help me pour it into the container with the tap. That’s the thing though: I had help to carry water. Here, the lab is pretty well-equipped. Everything is in one lab, I don’t have to go searching for beakers in one lab, distilled water in another, and reagents in a third. Everything is in one place. Magical. However, in Cuiabá there were tons of students to help out with the gritty work. Weighing, sifting, collecting, cleaning, carrying, there was usually always someone to help me with tasks. Here, it’s just me. Joan provides everything I need, but then I’m on my own. Of course, it’s a small experiment so it’s perfectly feasible and setting it up on my own means I have more control over it. After all, if things screw up, it’s my fault alone. It’s funny how my experience at the UFMT and here at UB seem complete opposites. I think UBC would be somewhere in the middle: the soils lab is well-equipped and there are always a bunch of students around. Honestly, I think it’s pretty nice that I’ve experienced working in three different labs. Of the three, UFMT was definitely the most challenging, but, boy, do I have some great memories! (Of course, now I can laugh)

So now everything is weighed, mixed, moistened and sitting in the fridge. Next week we will be setting up the cups for incubation and it will be all set to run. For 3 months I will be taking CO2 readings to measure the decomposition rates in the different soils with and without biochar. Hopefully, we will see some responses!

Primers passos

 


On Monday morning, Joan and I headed out of Barcelona to collect soil and manure for my lab incubation experiment. We had designed an experiment where we would add different stabilized organic matter amendments to soil: biochar (very stable), compost (semi-stable), fresh manure (labile, that is, easily decomposed). We would then examine how quickly decomposition occurred in the soil. To begin, we needed to gather the necessary materials. Since we already had biochar and compost, we had to collect the soil from a field and pick up manure from a farm.
First, pick up the manure. We drove for about an hour and a half out of Barcelona, over green, pine-covered mountains, through valleys filled with old towns and factories, past Montserrat with its funicular and ancient monastery. A little before 10am we arrived at the organic farmer/shepherd’s home with whom Joan often collaborates in the town of L’Espanyula. The owner, Josep’s, family has had the farm for generations and after inheriting if from his father, he transformed it into an organic farm. Josep took us to his sheep stables and with a pitchfork filled a large plastic bag with smelly manure for us, under the curious gaze of the sheep who soon went back to chomping on their hay. The surrounding mountains, large country home, and cool, calm morning definitely made a good case for a quiet, country life. As Josep described his ideas for testing and combining different conservation agriculture practices on his farm, you could tell how much passion he has for his livelihood, his animals, and his land.

All set with our stinky load, we headed out over more rolling hills to a field next to a forest in an area with acidic soils, one of the few areas around Barcelona with non-carbonated soils, that is with lower pH. Since we would be measuring the carbon in the soil with our organic amendments, a soil with already high carbon amounts could interfere with the measurements. After another hour of driving, we stopped at the side of a country road and walked up a trail to an open field. With a shovel, we quickly filled a few plastic bags with soil and were soon on our way back to Barcelona.

The rest of the week was spent preparing the soil (crushing clumps and sieving it) and trying to homogenize the manure by removing as much hay as possible and breaking up clumps (don’t worry, I wore gloves). However, on Thursday, in between reading articles and discussing the experimental design with Joan, we thought of going a different path toward isotope tracing. Isotopic tracing is a method that uses isotopes such as C14, C13, N14, or N15 to trace the origin of a substance. Carbon-14 dating, for example, is a common technique used in archaeology to date the age of ancient fossils.
I have not worked with isotopes before so I was excited to be able to learn a new technique. However, this meant we would have to change the experiment we had already planned and see where we could get the isotope analysis done. I sent an email right away to my supervisor, Mark, at UBC asking if we could analyse my samples there and he replied immediately with a Yes! So now we could move forward, but were back to square one, designing my experiment. The second experiment which we will switch to now looks like this: 2 types of biochars mixed with 3 different soils. We will be heading back out to collect soils next Monday. In the end, after playing around with poop for a couple of days, it turns out we will not be needing it after all. Oh well. On to more exciting things: isotopes! Oof, I have a lot of reading to do…