Q.Pine Shavings And Horse Manure Blend, Can I Use Them In The Garden To Give Fertilizer And Aeration For A Clay Like Soil? Thanks
The shavings are two years old

Certified GKH Gardening Expert
You can, but you may want to add some alkaline things in to balance out how acidic that could be. It is worth adding that composting these ingredients, first, is best. You may want to make sure that you have something like dolomitic lime. It will balance out the acid that the pine may add.
It is, also, worth noting that you may want to compost these, first.
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/improving-garden-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/using-fresh-manure-in-gardens.htm