Tree Nutrition and Fertilization Flashcards

Which component of a complete soil test is most important for determining lime or sulfur amendment rates for trees in New Mexico?

Answer: Soil pH and buffer pH

Soil pH and buffer pH measurements determine how much lime or acidifying amendment is needed to adjust pH to the target range for optimal nutrient availability.

What is the function of mycorrhizal fungi in relation to tree nutrition?

Answer: They extend the effective root surface area to enhance water and nutrient uptake

Mycorrhizal fungi form symbiotic relationships with tree roots, dramatically extending the effective surface area for water and nutrient absorption, especially phosphorus.

A newly transplanted tree in a New Mexico landscape shows slow establishment and pale foliage. A soil test reveals adequate macronutrients. What micronutrient should the arborist suspect given local soil conditions?

Answer: Iron

Iron deficiency is the most common micronutrient problem in New Mexico's alkaline soils, causing chlorosis and slow establishment even when macronutrients are adequate.

What is the primary advantage of using organic fertilizers such as compost or composted manure compared to synthetic fertilizers for urban trees?

Answer: Improved soil biology, structure, and long-term nutrient cycling

Organic fertilizers improve soil microbial activity, structure, and organic matter content, contributing to long-term nutrient cycling and improved soil health.

When calculating the amount of fertilizer needed to deliver 1 lb of actual nitrogen per 1,000 sq ft using a 10-6-4 fertilizer, how many pounds of product are required?

Answer: 10 lb

A 10-6-4 fertilizer is 10% nitrogen by weight; to deliver 1 lb of actual N you need 1 ÷ 0.10 = 10 lb of product.

Which practice helps prevent nutrient leaching and runoff when fertilizing trees in areas adjacent to storm drains or waterways in Albuquerque?

Answer: Use slow-release or controlled-release formulations and apply within the drip line

Slow-release formulations minimize nutrient runoff by releasing nutrients gradually, and keeping applications within the drip line reduces the chance of nutrients reaching stormwater pathways.

Phosphorus is often described as 'fixed' or immobile in soil. What does this mean for fertilizer application strategy near trees?

Answer: Phosphorus moves very little in soil and must be placed near active roots to be effective

Phosphorus binds strongly to soil particles and moves very little, so it must be placed close to the active root zone — ideally through injection or incorporation — to be available to trees.