I don't think you can find a free software like WinRHIZO Tron now.

Dear Bradley,

I am familiar with imagej. However, measuring dense roots are complicated. It need special software.

Hi Mehdi!

you know I'm not experienced in this topic but I found similar qustion on research gate:

https://www.researchgate.net/post/WinRhizo_or_similar_software

There is a link to a ImageJ plugin called "smartroot", it says it can calculate those things you've mentioned:

http://www.uclouvain.be/en-smartroot

Maybe this helps? I just wonder how do you use such values as length and volume of the roots? :)

Best regards!

Here is a link to some software you might find useful and it has a free trial period:

http://www.cid-inc.com/products/root-imaging/in-situ-root-imager

Hi 

I am working on root length and diameter and I have the same challenge. 

Thank you for the responses. Very helpful.

if you have scanned your root samples then send your images to me, i will calculate root traits data.

I'm also willing to do it and would be grateful if anyone recommends such free software.

thanks