By no means an expert, but I've gotten good plots with the same equipment you have. Get a soil test, and if you have work to do on it (aka lime fertilizer) I would start on that this spring. Personally I would not try to start a plot in the spring, I think it can lead to a lot of effort put in, and then frustration from the results. 1.5 acres with cowpeas starting out might be tough unless your deer and hog numbers are low. You are going to be fighting weeds, rainfall, and animal pressure.
If you really want to try something in the spring, I would try buckwheat. Deer will eat it, but it's a B team browse for them. Comes up quick, will shade out weeds, bees freaking love it. Spray the area with glyphosphate (get an atv sprayer) after spring green up. Then broadcast buckwheat in front of a rain.
Then in the fall, you can plant a brassica / turnip blend around September, and then overseed with cereal rye (not ryegrass! You want elbon rye) early to mid October in front of a rain. If the buckwheat took, and fought off the weeds, you shouldn't have to spray, it gets real stemmy once mature so it should easily break over from your drag. Deer like to feed on edges, so I will usually do Winfred brassicas and daikon radish in two strips, and cereal rye and red clover in two more strips. Rotate the strips every year
I have a broadcaster mounted on my front rack, and chain drag harrow I pull behind. Takes about an hour to do my 2 acres. You won't get magazine pictures out of these plots, but if you are patient about rain, you will be successful. Here is one I planted this fall into chest high goatweed (dead goatweed makes great cover btw, deer love feeding through it). Had to plant brassicas too early, so they only took in a small strip in the middle, but I overseeded around them with rye. By not breaking the soil, I don't have to fight off near as many weeds because I'm not opening the soil bank.