Get a soil test before you spend money on more of anything. It will tell you exactly what you need. Your nearest extension office can do it for you. I live in Mo so I don't know the cost or location. Adding compost never hurts.

I've never planted a fall veggie garden but there's a thread called Fall Garden Time on this page that might be helpful.

Fall garden : Your Basics are a good start like green beans they are 50-60 days to harvest I planted beets & radishes they came up in a couple days 3-4 for the beans you may have to water it a little I also plant spinach and lettuce in a few weeks they like it cooler. I start my own plants so cabbage and broccoli can make if you start the plants in time. Oct. 10 is the frost date here 40 miles due west of St. Louis so if your in Arkansas I'm sure its later

I start my tomato plants early and set them out in late April with protection or mid May when it is safer. Some varieties are late. If they are just now blooming that may not mean anything about your soil. Also it was very dry last winter and we haven't yet caught up here - 13 inches behind normal. If I plant anything for fall it will be leaf lettuce. A box over lettuce with some plastic or an old window and you can have lettuce late and early in the spring. I just hope no rabbits make a nest in my cold frame. I have found three rabbit nests in my garden this year pulling up weeds with baby rabbits flying through the air.