Soil Science and Fertility Flashcards
6 cards from real Agronomy practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Soil Science and Fertility flashcards as text
Which type of soil horizon is most important for plant root development and nutrient uptake?
Answer: A horizon
The A horizon (topsoil) contains the most organic matter and nutrients and supports the most root activity.
Potassium deficiency in crops typically first appears as what symptom?
Answer: Marginal leaf scorch on older leaves
Potassium is mobile in plants, so deficiency symptoms—scorched leaf margins—appear first on older, lower leaves.
Which practice is most effective at reducing soil erosion on sloped farmland?
Answer: Contour farming
Contour farming involves planting across slopes to slow water runoff and reduce soil erosion on hillsides.
Soil salinity is measured using which instrument or method?
Answer: Electrical conductivity meter
Electrical conductivity (EC) meters measure the concentration of dissolved salts in a soil-water solution.
What role do mycorrhizal fungi play in plant nutrition?
Answer: Extend root surface area for nutrient uptake
Mycorrhizal fungi colonize plant roots and extend hyphae into the soil, greatly increasing the root's effective absorptive surface area.
Which fertilizer source has the highest nitrogen content by weight?
Answer: Anhydrous ammonia (82-0-0)
Anhydrous ammonia contains approximately 82% nitrogen by weight, the highest of any commercially used nitrogen fertilizer.