Plowing again

I have a home movie from 50 years ago. They are plowing a square "40", starting in the exact center. This way they will always turn on un plowed ground, of course, when they finished they would have to be a few corners turned on plowing. There must be 10 rigs plowing that field. Kind of neat, I have never heard of that ever being done.
Brian(MN)

With one land on a square forty, they would be running empty a quarter mile at each end of the field on the final rounds. Not efficient.

NO. You are not understanding what they are doing. You start out with perhaps a 9' long furrow in exact center of field and when you get that land to 9' wide, 3 passes then the next time around at every corner with a right hand plow you raise the plow and make a left hand turn of 240*. 180* would be a 1 /2 turn with you going back the way you came, a 240 would be going a bit farther and makeing a 3/4 turn, (A perfectly square right hand turn) and start dropping your plow like if you were starting to plow the end off. If you are using for an easy example a 3 bottom 12" plow that cuts 3' wide every round is 12' longer than the previous round. First full round plowed, round would be 36' long, second 48', third 60', fourth 72', and fifth 84', sixth at 96' and seventh at 108', eight at 120 " and on up, you would see that each round gets a lot longer fast, and when you were done the last furrow would be 1 mile long. When you are finnished each side would be 1/4 mile long. The only time the plow is out of the ground is during that left hand turn and depending on make and model of tractor and plow could be as little as 15' per corner. You would only have 1 furrow completely around the outside of the field and if you did that every year and you were using a single disk you would always have a completely level field with no bowl shape developing on the outside edge of the field.

Around here,they used to start on the outide and plow around until they got to the middle. They had 4 headlands to plow from the corners to the center after they were done.

You are correct. I never thought, but the field would be more level this way, no dead furrows or lands.
Brian(MN)

What about the hill in the middle of the field, If you plow 6" deep each year you theorieticly would have a hill 6' high after 12 years. and a trench around the field you couldnt cross.
I know it wouldnt be that dramatic but plowing out for several years did the opposit.

If you notice I said with a single type disk and they will only throw dirt one way and that is out and every year that disk would fill in that last outside furrow and also hiting that center starting point 1 time with the disk straddling it would get rid of the bit of a raise there. If you were using a double disk normally you would plow in one year and out the next and keep alternating each year. That way keeps the field level.