Friday, September 26, 2014

Gals who weren't afraid to get their hands dirty...

One of the aspects of history that I find quite interesting is looking beyond the big players. When you delve deeper in the story, you find that, yes, the well known people in history were important. However, there are often more folks involved in the development of historical events. This is very true in science especially since researchers "stand on the shoulders of giants." Meaning as a scientist you aren't reinventing the wheel every time. You thankfully glean knowledge from those who have come before you. The development of soil science is no exception. Even during my education which occurred in the early 2000's the focus was on the key male scientists in soils. To learn about the lesser known folks in my beloved profession I decided for this post to focus on a few of the females in soil science that intrigued me. This may be a multiple part series as there so many interesting women in soils!


Campus garden. Photo courtesy OSU Archives.

Female students in Horticulture at Oregon State University preparing a vegetable garden near Benton Hall (~late 1800's). Photo Credit http://oregonprogress.oregonstate.edu/summer-2007/100-years-crop-and-soil-science.
Many of the first women working in the government organization now known at Natural Resources Conservation Service (formally Soil Conservation Service and preceded by Soil Erosion Service) were clerks and secretaries. A clerk out of Montana, Marjory A. McTavishdescribes driving in the USDA-SCS vehicles and stopping at a gas station. She asked the attendant to fill up the vehicle with gas. The man walked around the car and came back to the window asking "Does the government let women drive their cars?" 

During the 1930-40's, one of the first women that held a scientific/technical role in the SCS was Lois Olson. She was head of the Erosion History section under the Climatic and Physiographic Division of SES, which researched various documents and maps to determine characteristics of the landscape. Dr. Arthur Hall and her lectures on soil erosion history laid the foundation for many of the ways we think about soil erosion to this day. 


Article by Lois Olson and Helen Eddy published in Agricultural History
Vol. 17, No. 2 (Apr., 1943), pp. 65-72


The first woman to receive her Ph.D. in soil science was Ester Parsons Perry from the University of Berkeley in 1939. Her dissertation was titled "Profile studies of the more extensive primary soils derived from granitic rocks in California.” For anyone who has studied soil in California knows there are quite a few derived from granite as the Sierra Nevada Mountains are a granitic batholith. She began working for the California Agricultural Experiment Station (UC Berkeley) directly after where she remained for the whole of her career. She made her way up the ranks to the position of soils "specialist," but despite her contributions to soils in California she was never awarded the position of associate professor or a tenure track position. Perry ran the lab where well known soil chemist Gary Sposito was a student. She was also the first woman to join the American Society of Agronomy (ASA). 

Finally, we have the first woman to attend Soils 105, an infamous soil survey field course that began in the 1930's and is offered through UC Davis and UC Berkeley even to this day. In 1953, Eva Esterman, a UCB honors student, asked to take the class. She was given the option to graduate without taking the course, but declined. She attended the class chauffeured in a separate car and chaperoned by Dr. Earl Story's wife. Esterman was also given "comfort" breaks. The academic dean at the time, Dr. Frank Haridine, thought this was a complete disaster and stated that no woman would ever attend this class again. Obviously this was not the case as I know many women in my profession that have attended this class over the years. This is partly due to the aforementioned Ester Perry. She created Soils 105F, an all female version of the Soils 105 class that occurred from 1956 to 1959.  



A photo from the 2007 Soils 105 class, attended by many female students. http://lawr.ucdavis.edu/classes/ssc105/images/Photos07/IMG_2021.jpg


These are just a few of the stories about women in soils that I came across. There will be more posts to come that discuss woman and soils. Stay tuned!



Thursday, September 18, 2014

Turning, churning, worming....

In soil there is a term called "bioturbation." This process occurs in your yard, garden, field, and forest.  Ok so what exactly is bioturbation? Let's first break this word down into a couple parts.

"Bio" - living as in insects, animals, etc

"Tur" or ter - wearing away or breaking down

Bioturbation is the movement of soil by living organisms. Soil can move laterally, upward, or downward. Very obvious forms of this occur as gopher mounds! (Think Bill Murray's sisyphusian quest in Caddy Shack).

Photo Credit: http://news.moviefone.ca/2010/07/25/30-things-you-might-not-know-about-caddyshack/

Less obvious are those by plant roots and smaller organisms such as ants, earthworms, bivalves (e.g. clams), or even crabs.


Bioturbation of beach sand in Florida by crabs. 

Unfortunately, in the context of homeowners, golf course grounds keepers, or landscaping professionals bioturbation can appear as an aesthetic nightmare! The urge to run outside and play "whack a mole" can strike. However, when bioturbation occurs there are many benefits that these organisms are providing to the soil!

The benefits of bioturbation starts with in the simplest sense soil movement. Soil is moved around in the profile (i.e. 3D space that the soil occupies). With this movement there is transfer of organic matter from the surface to deeper in the profile or laterally to other areas. This incorporation of organic matter helps to improve water holding capacity, soil structure, and nutrient cycling. Earthworms are an example of soil fauna that consume organic matter, move through the soil, and deposit their excrement (i.e. worm castings) throughout the soil, which can improve soil conditions. Earthworms can turnover tons of soil in the course of a year. Over 10-20 years they can completely recycle the top 6 inches of soil.

Earthworm castings improving soil structure by creating "aggregates." 
Photo Credit: http://www.ipm.ucdavis.edu/TOOLS/TURF/PESTS/inearthwm.html

Other soil fauna burrowing and tunneling through the soil can help to break up soil compaction and allow for improved porosity. The increase in pores allows for better water and oxygen flow through the soil. This improvement is beneficial for plants and the microbial community (e.g. bacteria, fungi, and other oxygen lovers) in the soil. Increases in growth and nutrient cycling can result from this process.

So yes, the unsightly mounds from the larger fauna in the soil can disrupt the pastoral appearance of your yard. However, keep in mind the aforementioned benefits! This process of bioturbation can actually help to improve your soil for better plant growth and soil health. Resulting in sustained productivity in your soil for years to come!







Tuesday, September 9, 2014

Summer Oddities

This summer I was fortunate enough to take a few small trips where I came across some unusual organisms and of course amazing soil. With this blog entry I'd like to share a few of these.

The first oddity falls in the fungal designation.I came across this giant "puffball" hiking in Nevada just outside of Paradise Valley (northern NV). As evidenced by this organism not all of the state is a dry desert. The hike followed a creek that had various drainages contributing to it. This guy was in one of the wetter microclimates. The chapstick tube in the lower left corner gives you an idea of the scale of this fungi! I left the fungus in tact, but my best guess is that this is a West Giant Puffball (Calvatia booniana) commonly found in arid to semi-arid regions in late spring or summer. 

 Puffball fungi are ascomycetes, which have acsospores that release into the air. 
This puffball is filled with millions of spores!

The next specimen is a plant, but with animalistic tendencies! California Pitcher Plant a.k.a. Cobra Lily (Darlingtonia californica) is a canivorous plant. This plant can consume insects for nutrients. This is achieved by trapping insects inside the "pitcher" part. The long stem is hollow (see bottom left plant) except for very fine hairs and a slippery substance along the walls. The insects have difficulty getting out since the opening is not straight up. They eventually tire and are "digested" by the plant. These plants are known to produce an enzyme that breaks down the insect for absorption. 

CA Pitcher plant found in Shasta-Trinity National Forest.

The last notable encounter from this summer are serpentine soils/rocks. Note: serpentine is California's state rock! These soils develop from serpentine rocks that are composed of a variety of minerals. The minerals are similar in that they have an iron magnesium silicate backbone. The rocks weather (break-down) into soil. The serpentine soils have chemistry that is different from most in that there is a larger amount of magnesium than calcium. These quantities are typically in reverse in most soils. So why does this matter? Well, the plants that grow on these soils must be able to deal with this shift in soil chemistry. Serpentine soils have many "endemic" plants. This means there are plants growing in this soils that are specifically adapted and may only grow in this specific type of soil. Some examples are Leather Oak (Quercus durata), Milkwort Jewel Flower (Streptanthus polygaloides), and Kaweah River phacelia (Phacelia egena). Other plants such as Jefferey Pine (Pinus jeffreyi) and Incense Cedar (Calocedrus decurrens) are capable of growing on serpentine and less chemically challenging soils.

Serpentine soils in Plumas National Forest


Serpentine rock in Shasta-Trinity National Forest.