Plant Nutrition for Productive Pastures and Hay (Equine Systems)

What are essential nutrients for plants?

Nutrients that a plant cannot complete its life cycle without, have irreplaceable roles, and are directly involved in metabolism.

What are macronutrients?

Essential nutrients needed in large amounts, including primary macronutrients (N, P, K) and secondary macronutrients (Ca, Mg, S).

What are micronutrients?

Essential nutrients required in smaller amounts, including Fe, Mn, Zn, Cu, B, Mo, and Cl; they are critical despite being needed in tiny doses.

Why are micronutrients not considered less important?

Micronutrients are needed in small doses, but deficiencies can have severe consequences on plant health.

What impacts forage yield?

Under-fertilized grass stands produce less grazing and lower hay tonnage.

How do nutrient deficiencies show up in plants?

Symptoms often depend on whether a nutrient can be moved from older leaves to newer growth.

What are mobile nutrients?

Nutrients that move from old leaves to new leaves, often including N, P, K, and sometimes Mg.

What are less mobile nutrients?

Nutrients that show deficiency symptoms first on new growth, commonly including Ca, B, and Fe.

What form do roots absorb nutrients?

Primarily as dissolved ions in the soil solution.

What are the primary macronutrients?

Nitrogen (N), Phosphorus (P), and Potassium (K).

What is mineralization?

The process by which soil organisms break down organic compounds into plant-available inorganic nutrients.

How does soil pH affect nutrient availability?

Soil pH changes the chemical form and solubility of many nutrients, affecting their availability to plants.

What are the benefits of organic sources in plant nutrition?

Organic sources improve soil health, recycle nutrients, and may lower reliance on purchased fertilizers.

What are the risks of using organic sources?

Variable nutrient analysis, timing mismatch, and potential nutrient loss pathways.

What do inorganic nutrient sources primarily provide?

Mineral salts or mined minerals that supply nutrients in plant-available ionic forms.

What do N–P–K labels indicate?

The percent by weight of nitrogen (N), phosphorus (as P₂O₅), and potassium (as K₂O) in fertilizers.

Why are inorganic fertilizers sometimes seen as risky?

They can lead to leaching, runoff losses, and do not improve soil structure directly.

What is nitrogen immobilization?

When microbes temporarily 'tie up' nutrients in their own bodies while breaking down organic materials.

What should you consider when choosing between organic and inorganic sources?

Soil test results and production goals, including timing, nutrient balance, and the risk of nutrient losses.

What is a key factor in phosphorus management?

Placement and availability, not just total amount applied.

Why are soil tests important?

They help identify nutrient limitations and guide effective nutrient management strategies.

How does timing affect nutrient application?

Applying nutrients when crops truly need them is crucial for minimizing losses and optimizing uptake.

What is the role of soil microbes in nitrogen release?

They decompose organic materials, facilitating the mineralization process to make nutrients available to plants.

How can pH management assist in micronutrient availability?

Adjusting pH can make micronutrients more available to plants, reducing the need for additional applications.

What does a well-balanced nutrient strategy involve?

Ensuring that nitrogen needs are met without over-supplying phosphorus, based on soil test evidence.

What happens to phosphorus when over-applied with manure?

It can accumulate in the soil over time, increasing the risk of runoff and environmental issues.