Electromagnetic interference (EMI) poses a significant challenge to the performance of electronic devices by disrupting their normal operation. Shielding techniques are employed to mitigate these effects, traditionally using materials such as metals and carbon-based compounds. However, these conventional materials often generate environmental concerns due to pollution during production and the reflection of EMI back into the environment. In response, this study explores the use of agricultural waste, as a sustainable alternative for EMI shielding. Agricultural waste is rich in carbon content, which contributes to its dielectric properties and potential for EMI attenuation. In this work, the dielectric properties were characterized, and the shielding performance was analyzed through simulations using CST Studio Suite with waveguide transmission setup. Two structural designs which are the rectangular and pyramidal arrays were modeled to evaluate their impact on shielding effectiveness within the X-band and Ku-band frequency ranges, which are critical for security electronics. Experimental validation was conducted using a rectangular waveguide measurement setup. Results demonstrate that agricultural waste based shielding materials can achieve over 50% EMI attenuation, highlighting their potential as eco-friendly and effective alternatives to conventional shielding materials.