Please, thanks very much , please what advise will you give to improve my next application?
Try not to add anything that would be a liability to your finances. For example, a building under construction would require you to spend money so I wouldn’t advice that. I think just the plot of land should suffice. Also, if your wife is in a strong economic standing, show that as well to establish the fact that your immediate family is not an economic burden to you; for instance your wife’s bank statement. You can also show her credentials (educational background, current job etc.) to establish the fact that she can be independent with/without you.
In your situation, you’re applying as a student/father so you should be able to satisfy them on both levels thus how your responsibilities as a student will not interrupt your responsibilities as a father; Clear this up as well.
Lastly, look at your application critically to understand anything that would raise concerns and give justification as if you were in an interview with the visa officer. Put all these explanations in your SOP under subheadings.
Example;
1. Educational background
2. Professional development
3. Why university of xxxx?
4. Why Canada?
5. The reason why I’m still in Oman
6. My immediate family situation etc
A previous visa refusal should not be a problem so far as it wasn’t a security concern. If the previous reason has been cleared up in your current application, everything should be fine.