What is the percentage of photosynthetically active radiation (PAR), if incident solar radiation is considered 100%.

Options

A. 1
B. 0.5
C. 1-5%
D. 2-10% .

Answer

To determine the percentage of photosynthetically active radiation (PAR) when incident solar radiation is considered 100%, we can follow these steps:

### Step 1: Understand the Concept of PAR
Photosynthetically Active Radiation (PAR) refers to the range of light wavelengths that plants can use for photosynthesis. This range typically includes light from 400 to 700 nanometers.

### Step 2: Identify the Total Solar Radiation
When we say that incident solar radiation is considered 100%, we are referring to the total amount of solar energy that reaches the Earth's surface.

### Step 3: Determine the Proportion of PAR in Solar Radiation
Research indicates that approximately 45% of the total solar radiation falls within the PAR range (400-700 nm).

### Step 4: Calculate the Percentage of PAR
Given that the total incident solar radiation is 100%, we can conclude that:
- Percentage of PAR = 45% of total solar radiation.

### Final Answer
Therefore, the percentage of photosynthetically active radiation (PAR) is approximately **45%** of the incident solar radiation.

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