The soil underneath our new DOT garden has suffered thirty years of abuse; compaction, a monoculture of Kentucky blue grass, chemical fertilizers, herbicides and irrigated with highly mineralized water. This abuse is rampant the world over.
Before we began the restoration of the soil that was to become the DOT garden’s meadow, we needed to take the pulse of our soil, to know what signs of life might still be present.
We called our local extension office and set up an appointment to teach our students how to collect and analyze our soil. Cheryl Kent, an NMSU extension soil scientist brought her soil auger, test kits and expertise.
After a short introduction by Cheryl, the students used the augers and applied their elbow grease to drilling down into the cement-like ground to collect 6 to 8 inches of soil. They labeled and packaged the soil and we sent it off to a lab at Colorado State University www.ext.colostate.edu for chemical and physical analysis. While we waited for the results, the students performed their own analyzes in the classroom. Using a colorometric procedure, test kits available from La Motte, the students tested the soil for nitrate, phosphate, potassium, and pH. In addition, the students analyzed the soil for water-holding capacity, percolation rate and soil texture, see this lab procedure.
Both the CSU report and our own analyzes confirmed that almost no organic matter remained in the soil. Our soil pH is basic, consistent with the limestone, parent rock capstone of the Sandia Mountains, and our soil nutrients are all low. Below the surface layer of the nearly impenetrable hard-pan, the texture is a sandy clay loam, which means that the soil will drain at “low to very low rate”.
Though our soil has a high lime content, it does not suffer from the most serious affliction, soil salinization.
The creation of soil in a natural system takes thousands of years, as living things grow, die and decompose, recycling and adding nutrients, providing structure, increasing the soil’s ability to hold water and nutrients in place. A heavily degraded soil will recover on its own in time, lots of time. However, with a small amount of skill and a little knowledge and patience, humans can restore the earth’s fertility quickly and easily. The Land Institute in Kansas can teach us to repair the great prairies of the world. In our own desert Southwest, Gary Nabhan, Bill DeBuyes, Brad Lancaster and Jack Loffler pioneers land restoration techniques that can help show us the way back to an earth noisy with the bustle of worms and percolation of water.