20 October 2008

Soil Students Learn Old Fashioned Methods of Field Testing Soil Quality

Everything old is new again.

If the Internet and the news are to be believed, many Americans are growing their own vegetables, baking their own bread and eating at home.

Part of the impetus is to save money while savoring great eats. Part of it is the food scares - grow your own salad greens to avoid e-coli. Also, with jobs becoming more scarce, there simply is more time to do things at home.

My relatively new interest in all things dirt has led me to looking for information everywhere. When we were in California a few months ago, hubby's step-mother generously allowed me to take his grandfather's soil science text book from the family library. In it, the author teaches soon-to-be-growers how to assess their own soils.

I love reading the old textbooks and cookbooks. They give me snapshots into our grandparents' and great-grandparents' lives. I wonder if the back-to the-earth movement of the 1960s and 1970s will return.

In today's issue of Science Daily, there is a story about soil scientist students learning to estimate the quality of soils the way it used to be done: by hand and feel. The students evaluate the soil and then lab equipment is used to confirm or grade their analysis.

Here are some excerpts from the article. Click on the link above to read it in full.

The ability to estimate soil texture-by-feel is an important skill that students and registered soil scientists should learn.

D.P. Franzmeier and P.R. Owens, Purdue University, write about how soil texture can be determined by using the texture-by-feel method in an article in the Journal of Natural Resources and Life Sciences Education.

When the texture-by-feel method is used, the estimator takes a soil sample about the size of a marble up to the size of a golf ball. The person estimates the texture by rolling, squeezing, flattening, and pressing the soil between his fingers. Each person develops his own technique for estimating texture. The important point is that while learning the technique, he must always compare his results with laboratory data.

A computer program assesses student performance for estimating particle-size distribution and soil texture. If the estimate coincides exactly with laboratory results, the score is 100%. If the estimate and laboratory results are as far apart as possible, at opposite corners of the texture triangle, the score is zero.

Soil Science Society of America has lots more information on the topic as well as the original article and links to more scientific journal articles.

2 comments:

Dee/reddirtramblings said...

I love coming here because I always learn something interesting. Thank you.~~Dee

Molly Day said...

And, I love that you stop by, Dee. Thanks for enjoying the same stuff I do.
M