The problem is that you don't know how much to add to 'fix' the problem. I don't either. It would take a soil analysis to figure it out and still, it would be guess work.
I think attempting DIY projects like this are great but, you have to find online resources that know what they're talking about. Anyone can make a video or write a blog but it doesn't make the information they are passing along necessarily accurate.
I would look to University research projects and Ag Extension programs for information, such as:
https://extension.psu.edu/home...
Obviously a good choice because its from a University.
But, I would also pay attention to these ladies because, first, I checked their credentials and second, they make sense after reading the Penn State article:
https://savvygardening.com/diy...
What you should notice in all these recipes is the numbers of ingredients and amounts of each used are very consistent. If you find a recipe that says you can do it all with peat moss and cow manure, be suspicious.
Your recipe had a lot of Peat Moss (no nutritional value but highly acidic - pH 4), Compost (that was good but still slightly acidic), cow manure (a good source of nitrogen but highly acidic), worm castings (another good source of nutrients and, finally, something with a more basic pH), and fertilizer. Your soil recipe is highly acidic - probably in the pH range of 4 - 5. Most plants like slightly acidic to neutral soil, pH 6 - 7. Your recipe is also heavy on nitrogen - plants use nitrogen to grow healthy green leaves but not fruit. Along with nitrogen, plants also need Potassium and Phosphorus plus a whole slew of micronutrients. But, if the pH balance is wrong, even though there may be enough nutrients in the soil, the plants can't use them.
Even if you follow one of the recipes in the articles linked, if you decide to deviate from the ingredients or add different amounts, you will mess with the pH and cause problems for your plants. Its all about chemistry, whether you are mixing potting soil or baking a cake.
Personally, I don't make my own potting soil. I don't see a cost savings and I don't feel like spending the time doing it. In my mind, there's no advantage.
