First I commend you for using something from contextures. That's one of my favourite sources of Excel information. Second, pivot tables are great, but I sometimes have trouble getting them to think like I do.

Do you have a second table or range somewhere that provides client details? If so, that adds some capabilities. I would do a second SUMIFS formula similar to below to sum the fields from that table for a client or farm to get the acres. After that, it's simple math to calculate yields.

Here's how I would approach getting the total bushels. In the formula, TableData refers to the area with the purple headings. If you don't have your data set up as an Excel table, then you would enter range names for each column or even the direct cells. I find it much harder to make sure the formula refers to the correct beginning and ending of the range if you don't use the table feature. However, I suspect you've already got that under control within the sample file from contextures.

My input fields are in yellow. Note that I have used the * character to show I'm willing to accept all entries in that field.

I hope this gives you a direction to go in. Let me know any more questions you have.