Latt
I know white dried out seeds are a sad thing to see. Your problem is probably just lack of rain. But I will share what I have found.
Back when I started out six and seven years ago in Wisconsin, my first two plantings lost alot to seeds drying out and mice and slug damage. The first years planting ended up with 20-25% surviving.
I think the biggest problem i had with dried seeds, is that too many of the seeds were left on top of the soil and not down into the soil. But I don't recall the soil being very dry. But the leves were very dry.
Since I moved to maine, I tried to make sure that the seeds were covered better with the soil. I noticed that any seeds that were left on top of the soil, by spring time most of those seeds were dried out. I think they somewhat get freezer burned between the soil and layer of leaves beneath all the snow. Our soil does not ever get very dry, except in the summer. We get an average of 33\" of rain a year, not counting the 9-10 feet of snow in the winter. This year we have gotten just over 37\" of rain so far. I wish I could send some your way.
Any way, the last four years I have used the hound dog hand cultivator and found churning up the top 1/2-3/4 inches of soil, it allowed the seed to fall a little deeper into the soil. Then after walking over every part of the bed with my boots, I would look for any seeds that are still laying on top of the soil. When I find a seed on top, I ust take my finger and poke it into the soil about 1/2\". Then if the soil does get dry on top, it's not killing as many seeds that would have been left on top of the soil to dry out. I know this is alot of extra labor on my part, but I do get about 85-90% germination. And usually the kids are the ones that poke the seeds into the ground.
I know there is that perfect combination of rain coming before and after you plant and some times the rain just wont come at the right times, so it puts the seeds at risk of drying out. But thats the chance we have to take.
Did you try cutting open any of the seeds that floated? Sometimes seeds can be dehydrated enough that they will float, but are still viable seeds. If the shell is dry but the inside is still plump, it would still float and yet still be a good seed if moiture is brought back to it.
Don't lose Hope!
classicfur