Assertion: The process of nitrification involves the decomposition of proteins of dead plants and animals, and nitrogenous wastes like urea. Uric acid. Etc. of animals to ammonia.
Reason: Nitrogen cycle is a sedimentary cycle.

Explanation

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that nitrification involves the decomposition of proteins from dead plants and animals, as well as nitrogenous wastes like urea and uric acid, into ammonia.

2. **Identifying the Correct Process**: The process described in the assertion is actually known as **ammonification**, not nitrification. Ammonification is the process where organic nitrogen from dead organisms and waste products is converted into ammonia.

3. **Understanding Nitrification**: Nitrification is a separate process that occurs after ammonification. It involves the conversion of ammonia into nitrites and then into nitrates by nitrifying bacteria. Therefore, the assertion is incorrect.

4. **Analyzing the Reason**: The reason states that the nitrogen cycle is a sedimentary cycle. However, the nitrogen cycle is primarily classified as a **gaseous nutrient cycle** because it involves the atmospheric component of nitrogen (N2) and its transformations in the ecosystem. Thus, the reason is also incorrect.

5. **Conclusion**: Since both the assertion and the reason are false, we conclude that the statement provided in the question is incorrect.

### Final Answer:
Both the assertion and the reason are false.

---