Root Development in Soils. Root Growth Hypothesis—Minimum Effort. Root Growth Hypothesis—Profile Rebuilding. Measure depth and root length density in situ Frequent measurement can reveal root birth and death patterns (root turnover) Soil genesis. Undisturbed. Four Treatments.
Minimum Effort (a.k.a. Builder’s Special)
4 in (10 cm) topsoil
4 in (10 cm) topsoil, interface scuffed by tilling
Includes compost, subsoiling, and topsoil
Vegetation and topsoil scraped and stockpiled
8 passes with a compactor at optimal moisture for compaction. Bulk density = 2.0 g/cm3
For the ET and PR treatments, the topsoil was rototilled to a depth of 8 inches (20 cm).
ET: to disrupt interface
PR: to prepare planting surface (eliminate clods)
Step 1: Apply 4 inches leaf litter compost
Step 2: Use backhoe to go down 2 feet, scoop, and allow to fall down to break up clods. Large clods may require a prod with the backhoe. Creates veins of compost deep in profile.
Step 3: Apply 4 inches reserved topsoil
Step 4: Rototill to 8 inch depth
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