Navigation Links
Students get a feel for soil-water relationships

MADISON, WI, August 2nd, 2010 - Using little more than PVC rings, a trashcan, and a scale, students can literally get a feel for soil water retention and field capacity, concepts that are important and useful in fields from farming to engineering.

The demonstration, developed by Adam Howard, Drs. Josh Heitman and Dan Bowman of North Carolina State University, was designed to illustrate concepts that can be difficult for students to visualize and understand, and the equipment for making measurements of these variables is expensive. They report their method in the 2010 Journal of Natural Resources and Life Sciences Education, published by the American Society of Agronomy, the Crop Science Society of America, and the Soil Science Society of America.

The demonstration begins by taping short rings of PVC pipe together into a tall column. That column is then filled with soil and placed in a trashcan, and filling the trashcan with water to saturate the soil column. Saturating the column represents a long, soaking rainfall event.

The column is then removed from the trashcan, and allowed to drain for a day or two. When the excess water in the soil is drained away, the water left is the water contained in the soil at field capacity. Then the rings of the column are separated and the soil in each ring is weighed. As the column is sectioned from the top to the bottom, students are able to feel the differences in the soil water content. The soil is then dried and weighed again to determine the water content in each ring.

The concept of field capacity is one that arises often in soil, crop, and horticultural science disciplines. Field capacity is generally defined as the water content of a soil after free water no longer drains from a thoroughly wetted soil.

Field capacity is generally reported as a single number, which would be the average of the water contents in the rings, but few who use this information know where that number originated. Nor do they realize that this there isn't one value throughout the depth of the soil, but a continuum of water concentration that increases as you move from the top of the column towards the bottom.

A number of factors influence this soil water content continuum, including the soil texture, or the size of the soil particles, structure, or the way those particles are arranged, and depth to the water table.

The water retention relationship is a valuable tool in many disciplines. This is a relationship that connects the energy status of soil water to the soil water content. The soil water energy status, or potential, is the driver behind water movement in soils. Potential is also what plant roots must overcome to extract water from the soil. Plants wilt at very negative potentials, because they can no longer overcome the tension in very dry soils that limit water movement.

Through this very simple and inexpensive demonstration, students are better able to understand the soil, water, and plant relationships that surround us every day.


Contact: Sara Uttech
American Society of Agronomy

Related biology news :

1. Middle school students co-author research on enzyme for activating promising disease-fighters
2. Students design early labor detector to prevent premature births
3. Tufts graduate students win $10,000 prizes
4. Perceptions of forestry students change through years of study
5. 3 UAB students awarded prestigious Goldwater scholarships
6. Students perceptions of Earths age influence acceptance of human evolution, says U of Minn. study
7. Biochemist researching computer models of protein structure that help high school, college students
8. Oregon State trains graduate students to be better TAs
9. Students learn environmental stewardship, improve science scores
10. UT Southwestern receives $700,000 from HHMI to promote medical education of Ph.D. students
11. K-State receives more than $780,000 to fund graduate students studying ecology, evolution, genomics
Post Your Comments:
Related Image:
Students get a feel for soil-water relationships
(Date:9/10/2015)... Sept. 10, 2015 Report Details ... Reveals Selling Opportunities and Revenue Prospects to Help ... of biologics, especially new drug classes? Get the ... ahead with exclusive market data and industry knowledge, ... developments, results, opportunities and sales predictions. Visiongain,s ...
(Date:9/10/2015)... , Sept. 10, 2015 Pursuant ... Clinic Wellness to create an interactive, image-based health ... health and wellness kiosk.  The unique assessment quantifies ... a number that suggests an individual,s biological age ... values as measured by the kiosk. ...
(Date:9/9/2015)... , Sept. 9, 2015  NuData Security announced ... solution-based milestones, furthering the company,s commitment to protecting ... fraud. NuData Security,s online fraud detection ... company,s growth cycle. The product combines continual analysis ... good user behavior from fraudulent behavior, allowing the ...
Breaking Biology News(10 mins):
(Date:10/13/2015)... ... 2015 , ... Clinovo recently appointed Jeff Parr and Ed Donaldson to its ... solutions business. , Jeff Parr has spent the past decade providing quality management software ... Fisher, and Ab Sciex to name a few. He is based in Salt ...
(Date:10/12/2015)... OAKS, Calif. and BRUSSELS , ... UCB (Euronext Brussels: UCB) today presented additional findings from an ... 1 The findings were presented today in an oral ... Research (ASBMR) 2015 Annual Meeting in Seattle ... --> The small exploratory sub-study data ...
(Date:10/12/2015)... , October 12, 2015 cell surface ... billion by 2022, according to a new report by Grand ... to rise in incidence of oncology diseases and other cell-associated ... is expected to reach USD 6.49 billion by 2022, according ... growth in demand can be attributed to rise in incidence ...
(Date:10/12/2015)... , October 12, 2015 ... to print version for enriched online experience ... media alternative to print version for enriched online experience ... user-friendly, multi media alternative to print version for ... world-leading provider of scientific, technical and medical information products ...
Breaking Biology Technology: