Hello Geraldine, 

Here is some information from the UNH Extension Website that you may find helpful:

Tilling garden soil each year is a common practice, but studies have shown that it can disrupt microbial communities that are beneficial for soil health and plant growth. In addition, disturbing the soil can bring new weed seeds to the surface. Some weed seeds in the soil can remain viable for years or even decades. When applying soil amendments such as lime, fertilizer, or compost the recommendation is to incorporate them into the top 4-6 inches, which conflicts with no or low-till gardening practices. Sometimes it’s necessary to till or turn the soil to get the best results. An alternative tool to gas or electric rototillers is a broad fork, which can achieve the desired effect with less soil disruption. With the exception of incorporating amendments or breaking up compacted soils, it may be best to keep tilling activity to a minimum.

Here is the actual link to the information.

https://extension.unh.edu/blog/2020/10/low-no-till-gardening

And here is a link to the Oregon State University Extension with further information.

https://news.oregonstate.edu/news/no-till-gardening-keeps-soil-%E2%80%93-and-plants-%E2%80%93-healthy

I hope this helps.