What You Need and “Things To Be Aware Of”
You will need a bottle of water. Be careful of passing cars.
Is that title punny enough for a soil based earthcache? I had to dig real deep…
The soils of the Taieri Plains are amongst the most fertile in New Zealand. This fertility coupled with a "milder than Dunedin" micro-climate allows a range of different agricultural and horticultural activities to take place. The fertility is due to the fact that the area is a large flood plain (300 sq km) for the Taieri and Waipori Rivers. Historically these rivers would flood distributing fertile silt across the land. Today, this is somewhat of an inconvenience and the Taieri has been stopbanked, preventing most flooding and the Waipori is under hydroelectric dam control.
View across the Taieri Plains
Soil is formed in a process called pedogenesis or soil evolution. It typically occurs over a very long time - the rate of formation is influenced by climate, living organisms and the composition of parent material (eg rock). Generally, weathering of parental material occurs first, this allow colonisation by lichen and moss and the formation of a simple soil. Further weathering and succession (and decomposition) of plants eventually may lead to the development of a rich soil. The process may take more than hundreds of years - in some areas soil is known to accumulate at a rate of 2.5cm every 100 years.
Soil texture describes the relative proportions of clay, silt and sand in the soil. Clay (< 0.002 mm in size) feels sticky when wet, silt (0.02 - 0.002 mm) feels floury and sand (2.00 - 0.02 mm) feels gritty. The proportions of these can give an indication of the how the soil was formed and its current suitability for different applications.
The 12 Soil Texture Classes
0. Preface any email with GC28FKD Getting the Good Dirt in the subject line and title and clearly note the question number and answer. You don't need to wait for a confirmation email to log but you might be asked for more info if your answers are slim.
1. Using the protocol supplied above work out the textural class of the soil (eg sandy loam). Email this.
2. Use the expanded textural triangle to take your answer from question one and find out the approximate percentages of sand, silt and clay. Email this.
3. What is the scientific name for soil formation? Email the answer.
4. An uploaded photo of task one being completed would be nice but not compulsory.
Bonus Question: This location looks apparently random but was chosen for a slight geographical anomaly. Flipping through waypoint or position attributes may reveal this. Bonus 3 points to the first logger to upload a picture of this unusual feature of the location - depending on satellite position this may not work every day!
Wikipedia articles on soil formation and the Taieri Plains
NASA's Goddard Space Flight Center website on soil texture(+ credit for texture protocol)
2010 Stegan’s EarthCache Masters Programme
Since it is not very feasible for many NZers to easily get more than two states for the earthcache.org masters programme and therefore not get past Bronze I’m running my own one on a number of Earthcaches that I plan to release this year (all things being equal) with the following points system:
5 points: First to find
3 points: 2nd to find
1 point: Logging a find
1-5 points: Special bonus questions.
Shared points for joint finds.
At the end of 2010, I’ll issue certificates for 1st, 2nd and 3rd and the first place getter will be awarded a geocoin. If I feel richer and/or it looks like this is popular I’ll upgrade the prizes.
Updated information and Leaderboard at: Stegan’s Earthcache Programme