Mixes of different size seeds require certain considerations at planting. The best method is to use a drill with two different seed boxes and the ability to sow the small grain at an inch and a half deep while sowing the smaller seeds at a quarter to one half inch deep and pressed firmly. Research has been done to evaluate sowing both sizes of seeds together at one inch deep. Depending on soil type, this may or may not be successful.
A heavier soil type makes this a risky method because the smaller seed will not emerge from that depth. Broadcasting seed of different sizes is affected by seed weight and density. Larger, heavier seeds tend to be distributed further from a cyclone seeder. Smaller and lighter seed do not carry as far and can be carried by the wind as well. The result can be streaking of seed with this type of seeding. Broadcasting seed, with or without light tillage, requires a higher seeding rate to obtain similar stand density. For these reasons, it is usually more successful to use a drill.
As always, working with your team of farm, nutrition and agronomy members will help to formulate a plan for your operation. These are guidelines to get started that hopefully will lead to a greater forage supply for your farm.