Hi Iluku,

Welcome to this great platform.

No,as you have figured out by now, it's not a ponzi scheme, as you do not need to bring any money in to get started...

Do not focus on earning money here, especially if you are a new comer. That won't work. Steemit is first a platform where knoweldge is exchanged and groups of interest form. The magic is that the money comes by itself when you write great stuff consistently.

Agronomy is quite a popular topic here, as most (serious) members are alternative thinkers. Sustainable solutions are saught for here, like in real research community.

My advise to you: write a scientific post about a specific agricultural topic (a topic where you are kowldgeable at), make aerated paragraphs, include every 3-4 paragraphs illustrations and pictures while respecting coppyright, (you can use pixabay.com for pictures you can use for free), cite your sources, and try to organise your article as a story. Then post it on Steemit using the #steemstem tag. Also, engage with the comments.

In might not work for the first posts, but keep at it, and if your content is good, things will turn out sweet.

Good luck!