soil tests will run you less than $10 a piece. As far as when to plant that information is on the back of the imperial products as is the info on how to plant. Half acre plots would probably be best for imperial clover or alpha rack. Imperial does have a new soy/lab lab product. If you were to go with the soy/lab lab you would have to invest in a deer repellent. This would be put around the plot to repel the deer until the soy was about knee high and then removed to allow the deer in. It would be extra work but if you know anything about how much deer HAMMER soy it would be worth the extra effort.