RE: how much round up
When we get recommendations from our crop consultant to spray soybeans/corn with round-up - or any glyphosate - it is usually a 5 gallon/acre water rate using one quart of roundup and some surfactant.
Example fill for our sprayer - 1000 gal cap. is as such: 10 gallons Surfate (Surfactant sold by Agsco Inc.), 50 gallons glyphosate -
5 gallons per acre - 200 acres on one fill = 200 quarts/4quarts/gallon = 50 gallons
Sometimes we use 10 gallon nozzles but the rate stays the same - just fewer acres covered/fill.
I apologize if my math is incorrect in any way - the rates are correct tho.