A few comments:
1) I entirely agree with Ermi, please don't 'salt' your yard. Instead, use organic fertilizers, i.e., no harsh chemicals (twice a year should be enough unless it's in the emergency ward), and concentrate on building up your soil and turf grass until it's the healthiest it can be, which, BTW, will also run out weeds on its own and be easier to maintain. If you want to retain water in your soil, healthy turf grass does it better than anything else.
2) Ground radials for AM monopole antennas is the way to go on land. There are lots of articles and posts right here with URLs to websites with diagrams, illustrations, and photos, of which I've personally spent at least a hundred hours worth of reading and research. Involves some theory for sure, and there are new takes on it, of course, but it's how AM radio has worked successfully for 80 years or so.
I have also done other research, but that's because I want to see if we can get reasonable range with an apartment antenna, or other areas where space is severely limited, especially vertical space. I hope to start construction work on those ideas in the Spring.
I found some ground wave charts ... I believe these are copies of the ones referred to in 73.184:
For some strange reason, the URL didn't paste in right ... try again ...
Having to explain an attempt at humor sorta takes the fun out of it.
Neil