Question

The total N contents in livestock manures are given below. Arrange in decreasing order:
(A). Dairy (solid)
(B). Swine (liquid)
(C). Poultry (solid)
(D). Dairy (liquid)
Choose the correct answer from the options given below:

• A. (A), (B), (C), (D).
• B. (D), (C), (B), (A).
• C. (C), (A), (D), (B).
• D. (C), (B), (A), (D).

Hint:

Poultry solid manure (C) is always the most nutrient-rich animal manure, while liquid dairy manure (D) is highly diluted with wash-water, making it the least concentrated.
This places (C) first and (D) last, matching only option (D).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Livestock manures are valuable organic fertilizers.
Their nutrient content (specifically Nitrogen, \( \text{N} \)) varies widely depending on the animal species, their diet, and whether the manure is collected in solid or liquid form.

Step 2: Detailed Explanation:
Let us compare the nitrogen concentrations of the listed manures:
- Poultry solid manure (C): This is the most concentrated common livestock manure, typically containing \( 2.0\% - 4.5\% \, \text{N} \) on a dry-weight basis.
This is because poultry excrete nitrogen as uric acid, which is highly concentrated.
Therefore, (C) is the highest.
- Swine liquid manure (B): While liquid manures are diluted, swine waste has a higher nitrogen content than dairy waste.
It typically contains \( 0.5\% - 0.7\% \, \text{N} \), consisting primarily of soluble ammonium nitrogen.
- Dairy solid manure (A): Dairy cattle consume high-fiber diets, and their solid manure contains moderate amounts of slow-release organic nitrogen, typically around \( 0.4\% - 0.5\% \, \text{N} \).
- Dairy liquid manure (D): This is heavily diluted with barn wash-water, resulting in a very low nitrogen concentration, typically \( 0.1\% - 0.2\% \, \text{N} \).
Therefore, the decreasing order of total nitrogen content is Poultry solid (C) \( > \) Swine liquid (B) \( > \) Dairy solid (A) \( > \) Dairy liquid (D).

Step 3: Final Answer:
The decreasing order of nitrogen content is (C), (B), (A), (D).