Soil, Water, and Vegetation Management
Soil, Water, and Vegetation Management
This domain tests the growing system: soil texture and structure, compaction, pH, organic matter, infiltration, irrigation, plant selection, and establishment. Expect questions that connect soil conditions to plant health and water use.
Core rules
- Texture describes sand, silt, and clay proportions; structure describes how particles aggregate. Compaction destroys structure and reduces infiltration.
- Test soil before specifying amendments. pH affects nutrient availability; organic matter improves water-holding capacity and biological activity.
- Match plants to the site's water, light, soil, and climate. Group plants by hydrozone so irrigation matches water need.
- Avoid planting too deep. The root flare should remain visible, and the planting hole should be wide but not overly deep.
- Establish irrigation for survival, then transition to site water. Overwatering causes root disease and runoff.
Worked example
A site has compacted clay subsoil and 6 inches of topsoil. The proposal is to fertilize heavily and plant trees. The reasoning: fertilizer does not fix compaction. The better response is to loosen the subsoil, widen the planting area, protect the root zone from construction traffic, amend the topsoil based on tests, and mulch. Fertilizer may be unnecessary at planting and can worsen water-quality problems.
Traps
- Specifying amendment without a soil test.
- Planting trees too deep or burying the root flare.
- Mixing high- and low-water plants on one irrigation zone.
- Assuming native plants need no establishment water.
- Ignoring construction compaction and drainage.