Soil Science and Irrigation Flashcards

What are the three primary macronutrients found in most commercial fertilizers, represented by the NPK ratio?

Answer: Nitrogen, Phosphorus, Potassium

NPK stands for Nitrogen (N), Phosphorus (P), and Potassium (K), the three primary macronutrients essential for plant growth and the basis of fertilizer labeling.

Which soil texture has the highest water-holding capacity?

Answer: Clay soil

Clay soil has the highest water-holding capacity due to its tiny particle size and large surface area, though this can also lead to poor drainage and aeration.

What is the 'field capacity' of soil?

Answer: The amount of water soil holds after excess drainage has occurred

Field capacity is the amount of moisture soil retains after gravitational water has drained away, representing the optimal moisture level for most plant growth.

What does a soil percolation test measure?

Answer: The rate at which water drains through the soil

A percolation (perc) test measures the rate at which water drains through soil, critical for determining irrigation scheduling and suitability for features like rain gardens or septic systems.

Which irrigation system type delivers water directly to the root zone, minimizing evaporation and runoff?

Answer: Drip irrigation system

Drip irrigation delivers water slowly and directly to the plant root zone, reducing evaporation, runoff, and foliar disease by keeping foliage dry.

What is 'organic matter' in soil and why is it important for landscape planting?

Answer: Decomposed plant and animal material that improves soil structure, fertility, and water retention

Organic matter consists of decomposed biological materials that improve soil structure, increase water and nutrient holding capacity, and feed soil microorganisms essential for plant health.