There are several YouTube channels and video lectures available that can be helpful for Agriculture Optional preparation for the UPSC exam. These channels provide comprehensive coverage of the Agriculture Optional syllabus and offer valuable insights and guidance for the exam. Here are some notable channels and video lectures that can assist you in your preparation:

1. Unacademy: Unacademy is a popular online learning platform that offers a wide range of courses, including Agriculture Optional. They have a dedicated channel for UPSC preparation where you can find video lectures by experienced educators. These lectures cover various topics of the Agriculture Optional syllabus and provide in-depth knowledge and understanding of the subject.

2. EduRev: EduRev is an online learning platform that provides a vast collection of educational resources, including video lectures for Agriculture Optional preparation. They have a dedicated section for UPSC preparation where you can find video lectures by experts in the field. These lectures are designed to cover the entire syllabus and provide a comprehensive understanding of the subject.

3. Civils Daily: Civils Daily is another popular YouTube channel that offers video lectures for UPSC preparation, including Agriculture Optional. They provide detailed explanations of concepts and theories, along with strategies and tips to tackle the exam effectively. The lectures are delivered by experienced educators who have a deep understanding of the subject.

4. Mrunal Patel: Mrunal Patel is a renowned educator who provides free video lectures on various subjects, including Agriculture Optional. His lectures are known for their simplicity and clarity, making complex topics easy to understand. He covers the entire syllabus in a structured manner and provides valuable insights and tips for exam preparation.

5. Mitra's IAS: Mitra's IAS is a well-known coaching institute that offers video lectures for UPSC preparation. They have a dedicated channel for Agriculture Optional where you can find lectures by experienced faculty members. These lectures cover all the important topics and provide a comprehensive understanding of the subject.

In addition to these channels, there are several other individual educators and coaching institutes that provide video lectures for Agriculture Optional preparation. It is important to evaluate the quality and credibility of the content before relying on any specific channel or lecture series. You can refer to reviews and feedback from other aspirants to make an informed choice.