Bobwhite quail and other upland birds need three things from a planting: seed-producing plants, legumes that draw the insects chicks live on, and open structure at ground level so birds can move and chicks can travel under overhead cover.
Partridge pea is a quail staple; pair it with grain sorghum, millet, and sunflowers for seed, plus cowpeas or sunn hemp for insects and light cover. Egyptian wheat makes excellent screening and edge cover.