Question

You analyze a soil sample for a farmer that has been dealing with fertility issues on her land. You find that it is deficient in all of the soil-derived macronutrients. Which one of the following is macronutrient derived from the soil? A. carbon B. nitrogen C. hydrogen D. iron E. oxygen

Short answer

B. nitrogen

Step-by-step solution

Understand Soil-Derived Macronutrients

Macronutrients are nutrients required by organisms in large amounts. Soil-derived macronutrients are those that plants obtain primarily from the soil.

List Common Soil-Derived Macronutrients

The key soil-derived macronutrients commonly include nitrogen (N), phosphorus (P), and potassium (K).

Evaluate Each Option

Go through each option to check if it is a macronutrient and if it is derived from the soil:- A. Carbon: Derived from air as CO2.- B. Nitrogen: Derived from soil.- C. Hydrogen: Derived from water (H2O).- D. Iron: Micronutrient, not macronutrient.- E. Oxygen: Derived from water and air (as O2).

Identify the Correct Answer

Since nitrogen (B) is the only macronutrient in the list that is derived from the soil, it is the correct answer.

Key concepts

Soil Fertility

Soil fertility is crucial for healthy plant growth and optimal crop yields. It refers to the soil's capacity to provide essential nutrients to plants in adequate amounts and proper proportions. Several factors influence soil fertility, including the presence of macronutrients, soil texture, structure, organic matter, and pH level. When soil fertility is low, plants may exhibit stunted growth, yellowing leaves, and decreased productivity.

In agriculture, maintaining soil fertility involves regular testing and amending soils with fertilizers that supply missing nutrients. Organic methods, like adding compost or manure, can also improve soil fertility by enhancing soil structure and microbial activity.

Plant Nutrition

Plant nutrition focuses on the various nutrients that plants need to grow, develop, and complete their life cycles. Essential nutrients are categorized into macronutrients and micronutrients. Macronutrients are required in larger quantities, such as nitrogen, phosphorus, and potassium. Micronutrients, although equally important, are needed in smaller amounts and include elements like iron, zinc, and copper.

Macronutrients in plant nutrition play specific roles:

• Nitrogen (N): Vital for protein synthesis and leaf growth.
• Phosphorus (P): Key for energy transfer and root development.
• Potassium (K): Important for water regulation and disease resistance.

Each nutrient deficiency has distinct symptoms. For instance, nitrogen deficiency often results in yellowing leaves, while phosphorus deficiency can cause dark green foliage and stunted growth.

Macronutrients in Agriculture

In agriculture, macronutrients are the backbone of fertilizer regimes to ensure healthy crop production. These nutrients include nitrogen, phosphorus, and potassium (often abbreviated as N-P-K). Farmers apply fertilizers based on soil tests to replenish these nutrients and maintain soil fertility.

These macronutrients have specialized formulations for different crops and soil types, ensuring optimal nutrient availability.

The role of macronutrients includes:

• Nitrogen (N): Enhances leafy growth and overall vegetative development.
• Phosphorus (P): Supports root establishment and flowering.
• Potassium (K): Crucial for overall plant health, enhancing resistance to diseases and adaptation to environmental stresses.

Balancing these macronutrients is essential for sustainable agriculture and maximizing crop yields. Proper fertilization techniques, like split applications and precision farming, help in the efficient use of these nutrients.