The next part of my project involved writing an effective guide for the students to use their soil stability test kits.(The link to the soil stability test kits that the kids will be using is here ). The kids will be using their kits to test the soil surrounding their school and determine its quality, which usually includes testing the soil density, proneness to slacking, permeability to water, and nutrient content.
Soil density and permeability to water are relevant in testing how easily water passes through soil, which then relates to slacking.(No, not the type that high school seniors are notorious for). Slacking is the breakdown of large, air-dry soil aggregates into smaller micro-aggregates when they are immersed in water. Usually when environmental scientists talk about slacking, it is in regards to the the soil’s ability to resist erosion. The better the soil’s ability to resist erosion, the higher the quality of soil.
Bad soil quality could mean a plethora of things for the environment. Stability is critical for infiltration, root growth, and resistance to water and wind erosion. Unstable soils disintegrate during rainstorms. Dispersed soil particles fill surface pores and a hard physical crust can develop when the soil dries. Infiltration is reduced, which can result in increased runoff and water erosion, and reduced water available in the soil for plant growth. A physical crust can also restrict seedling emergence.
Soil quality is also crucial when determining whether or not the students could build a rain garden. If the soil is too loose, building a structure on top of it will be impossible. But on the other hand, if a hard crust has formed over the soil, it will be difficult to break ground to build the structure.
There is the possibility to improve the soil stability of a certain area, mostly by increasing the amount of organic materials in the soil or applying specialized organic compounds. Specifically, common solutions include:
- Crop Rotation
- Covering Crop
- Pest Management
- Prescribed Grazing
- Residue and Tillage Management
- Salinity and Sodic Soil Management
- Surface Roughening
Anyways, this all needed to be conveyed to the students who are attempting to learn about their school’s soil. I put together a few informational sheets that convey all of this (in more simple language) and encourage the kids to think about it while they are taking soil samples. My next step is to obtain the base map of the school (a map that shows relative elevation and often other environmental factors) so I can begin to understand the soil’s proneness to erosion, in order to relate it to the student’s tests. I’ll keep you posted!