I am assuming you are talking about this years paddy and not for next season. If so, weed would have already started to emerge.
I am not against using azolla. To start and maintain azolla culture water logging is necessary. it will dry out when no water is avilable, but by then paddy would have established and weed will not bother paddy. I have not yet tried it. Was initially planing to do it. Not just that azolla ultimately lands in the water bodies completely covering surface.
link below. farmer uses a cycle to de-weed.
hindu.com/seta/2010/04/29/st … 601500.htm
You can try using iron fork hoes attached to a motorcycle or some other mechanised device. Using a cycle on 7 hectares is not going to work. You will need a skilled labor to achieve this task.
this will also add little soil on the root of paddy. you will achive good results(roots will not damage under scorching heat)
What I do is when I de-weed, I use the same weed as mulch. it suppress growth of the same weed or others. as some weed grow back just from a hair like root.
Traditionally in Kerala farmers add cashew nut leaf to control weed just after paddy emerges(some add the leafs just after tilling, it also acts as compost and paddy roots find it easy to spread). You can try any flat leaves which stick to the ground. so no weed can emerge. (but 7 hectares is to much I believe).