California no-till drills are custom built. Each drill is an individual for calibrating seed and fertilizer application. The seed chart refers to common seeding rates and rates with 6- to 7- inch row spacing.
Please use this as a general guide. Drilling two ways using 10# per acre for a 20# seeding rate is done for alfalfa. You can put down too much seed. Look in the drill row to check how much seed is actually going out; use your pocket knife to check. Putting seed on top of seed is just a waste of your money and time.
Fertilizer can wear out a drill faster than anything else. Clean out the fertilizer box after each job. Wash it out if powder is accumulating. Spray with a light oil or diesel (never do this in a seed box). We recommend no more than 50# of nitrogen with the seed at planting.
Do not use ammonium nitrate or ammonium sulfate.