Do not plant directly in the rip because water will frequently use the rip as a channel, uncovering some seedlings and burying others. The taproot of the longleaf will find the rip and allow the seedling to root deeper, thus minimizing the chance of wind-throw and increasing water availability to the tree. Try to anticipate how much the soil will erode so that the root collar will end up at the soil surface. Planting too shallow will result in a seedling that dies quickly. Planting too deep will result in a seedling that dies slowly.
Good compaction is needed to eliminate air pockets around seedling roots.
Heavy duty machines do a better job of packing than the typical hand planting crew. As bareroot seedling roots are very large, planting shovels work best in opening a planting hole large enough to accommodate the root system. Many containerized seedlings have tools designed especially for their plug size. Using the correct tool will result in less root deformation, better survival, and better long-term growth. Be sure your planting contractor understands your CRP or WHIP contract.