Exam #2- HORT-120 Flashcards
What are the two processes in which nutrients move in the soil?
- Diffusion
- Active transport
Briefly explain the process of diffusion in soil.
Diffusion is the particle movement across a high to low gradient. Hot water speeds up diffusion while cold water slows it down.
What is the first structure to pop out of a germinating seed?
The radicle, it is an embryonic root
What are the two types of roots?
- Fibrous
- Tap
What is a tap root?
a primary root that grows vertically downward and gives off small lateral roots
Define an essential nutrient
An essential nutrient is one that is needed for a plant to complete its lifecycle. there are 18.
How does the root of a plant grow?
Roots grow from meristems. They push outward in search of resources.
What does it mean when we say “roots explore the soil?”
Roots explore the soil by maximizing growth where nutrients are in high concentrations and minimizing growth where nutrients are sparse.
What do plant nutrients do?
Plant nutrients make up plant tissues, act as catalysts, control the permeability of membranes, act as coenzymes and enzyme inhibitors.
Macronutrients vs Micronutrients
Plants need more VOLUME of a macronutrient than a micronutrient, this has nothing to do with how important the nutrient is.
Explain Liebig’s law of the minimum
Plant growth is limited by the plant’s nutritional requirements, therefore growth is limited by the nutrient with the lowest availability.
What are the primary macro nutrients?
Nitrogen, phosphorus, and potassium. These three elements are found in most fertilizers. N-P-K
What are some important non-mineral micronutrients?
Carbon, hydrogen and oxygen. Plants receive these from air and water.
What are the three secondary macro nutrients?
Calcium, magnesium, and sulfur. Typically not included in most fertilizers because it tends to be plentiful in the soil.
Micronutrients
needed in trace amounts for the normal growth of the plant. Leaves and grass clippings are a good source of micronutrients.
Define a fertilizer
A cultural amendment that provides chemical elements that improve plant growth/ production. Can be organic, inorganic, slow release or fast release.
Organic fertilizers
Organic fertilizers are derived from organic sources
Inorganic fertilizers
Inorganic fertilizers are synthetic or chemical products that provide essential nutrients to plants.
Slow release fertilizer
Slow-release fertilizer releases a small, steady amount of nutrients over time and is used for root development. It is coated with sulfur, polymers, and wax. It reduces water loss in leaching and usually requires fewer applications therefore saving money.