Ann: OHD Project Update, page-234

A soil test every 3 or so years is imo enough where i farm unless there seems to be a problem. Cant speak for other areas as ive got no experience in them. If you have a healthy soil and your crop uses x amount of nutrients its pretty easy to calculate the nutrients to be replaced the following crop. In an ideal world farmers would love to know how there soil is going every few months, but unfortunately medicare doesn't cover the costs.