Seed can be an expensive input, but a poor crop stand can be lost profit. To maximize your seed, still get the stand needed to optimize yield, start calculating the real seeding rate needed for the plant stand desired and not gauging seeding rate by lbs/ac or bu/ac.
The following are the standard recommendations for FINAL plant stand, not what you are putting in the ground. Germination, TKW and mortality are very important to use in the equation to determine actual seeds/ac to plant. For example, if you assume your germination is 96% and its only 85% and conditions turn cold and wet (increasing mortality), you may have a lot thinner stand than you anticipated (which could mean a harder time controlling weeds).
|Grain Crops||Oilseed Crops||Pulse Crops|
|Mortality Rates (%)||10-15||10-15||10-15||10-15||20-60||10||40-50||5-15||5-10||5-10|
*Navy Bean = pinto beans on lower end and navy bean require higher plant stands
Source: Manitoba Agriculture, Canola Council of Canada, Flax Council of Canada, Ontario Ministry of Agriculture, Food and Rural Affairs
Seeding Rate (lbs/ac) = target plant stand/ft2 x TKW (g) / % expected seed survival x 10
e.g. FLAX Seeding Rate= 45 plants/ft2 x 5g (TKW) / ((88% germination x (1- 40% mortality)) X 10 = 43 lbs/ac
Using 1000 Kernel Weight for Calculating Seeding Rates – http://www1.agric.gov.ab.ca/%24department/deptdocs.nsf/all/agdex81
Optimizing Plant Establishment – http://www.gov.mb.ca/agriculture/crops/production/pubs/optimizing-stand-establishment-in-less-than-optimal-conditions.pdf