Tilling the ground is a good way to improve the drainage and reduce the number of macropores open to the soil surface. Amending the soil with compost can often increase permeability and pore size. Dense, compacted soils have a much lower rate of permeability than soils made up of looser particles. Send a sample of your soil to the laboratory of your choice to have it analyzed. Be sure to request recommendations as well as results so you will know how to amend your soil deficiencies.
Different plants require different nutrients so it's important to plant accordingly.
In general, nitrogen promotes leafy top growth, phosphorus promotes root development, and potassium promotes winter hardiness. Specific recommendations can be found in publications available at the OSU Lane County Extension Office at 950 West 13 th Avenue.