Plant Nutrient Limitation and Nutritional Adaptations

What are the most important nutrient limitations to agricultural crops?

Nitrogen, Phosphorus, and Sulfur.

What nutrient elements do plants obtain from the soil?

Macronutrients and Micronutrients.

What adaptations do plants have to overcome soil nutrient limitations?

Nitrogen-fixing symbiosis, mycorrhizal associations, parasitism, and carnivory.

What is the benefit of association with nitrogen-fixing bacteria for plants?

Plants receive ammonia (NH3) from bacteria that fix nitrogen (N2) gas.

What do legumes and Rhizobium bacteria gain from their symbiotic relationship?

Legumes gain nitrogen from bacteria, while bacteria receive carbohydrates and a protective environment from legumes.

What enzyme do Rhizobium bacteria use to fix nitrogen gas?

Nitrogenase.

What is the annual global production of ammonia from nitrogen-fixing bacteria?

80 million metric tonnes.

What are mycorrhizal associations?

Symbiotic relationships between fungi and plant roots that enhance nutrient uptake.

What nutrients do plants derive from mycorrhizal fungi?

Phosphorus, nitrogen, and other minerals.

What is the role of carnivorous plants?

They capture and digest insects to supplement their nutrient requirements, particularly nitrogen.

What is the significance of phosphorus in agriculture?

It is essential for ATP energy transport, DNA/RNA structure, and cellular regulation.

What are the consequences of excess fertilizer runoff?

Coastal eutrophication, algal blooms, dead zones, and nutrient loss from land.

What is the main challenge regarding phosphorus for fertilizers?

We are running out of phosphorus for fertilizer production.

What is the role of the plant root microbiome?

Some soil bacteria stimulate plant growth and enhance nutrient uptake.

What is the advantage of mycorrhizal fungi to plants?

Plants gain access to nutrients beyond their root reach and protection against pathogens.

What is parasitism in plants?

It is when plants derive nutrients from a host by projecting into its tissues.

What is an example of a photosynthetic plant parasite?

Mistletoe.

What types of habitats are carnivorous plants typically found in?

Nutrient-poor habitats like bogs and tropical rainforests.

What is one way traditional sustainable agriculture enhances nitrogen availability?

Crop rotation with nitrogen-fixing legumes.

Who was George Washington Carver?

A prominent agricultural scientist who promoted alternative crops to reduce soil depletion.

What is the impact of nitrogen-fixing symbioses on agriculture?

They enhance nitrogen availability, reducing the need for synthetic fertilizers.

What is the function of nodules in legumes?

They house nitrogen-fixing bacteria and provide carbohydrates for energy.

What is the primary benefit of crop rotation with legumes?

It replenishes soil nitrogen and increases crop yields without artificial fertilizers.

How do carnivorous plants supplement their nutrient intake?

By digesting insect prey to obtain nitrogen, phosphorus, and potassium.