Soil 364 Final Exam

Plant Nutrient Deficiencies

What elements are excluded in plant nutritional analysis?

Carbon, hydrogen, and oxygen

What do deficiency symptoms depend on?

The function and mobility of an element

How can an element be a toxicity?

If the concentration causes a 10% decrease in dry matter

Does an excess of macronutrient or micronutrients usually result in a toxicity?

Micronutrients. Too much of these can cause deficiencies in macronutrients.

How are deficiency symptoms a secondary effect?

Because it results from a combination of interdependent factors from a severe lack of a nutrient.

Can a deficient plant function properly?

No.

What is hidden hunger?

It is when a crop needs a nutrient but shows no symptoms. It’s a puzzling issue in Ag.

What is a symptom of Nitrogen deficiency?

General chlorosis of lower leaves. In corn, the stems and underside of leaves may turn purple.

What is a symptom of Phosphorus deficiency?

Think dark green leaves

What are symptoms of Potassium deficiency?

White necrotic spots on leaflet margins, interveinal chlorosis in lower leaves.

What is a symptom of Sulfur deficiency?

The whole plant is stunted and lighter colored. It is often confused with a Nitrogen deficiency.