When it's time for a new roof, you've got a lot of new choices these days, many of which will last more than 50 years. New engineered shingles are made to look like cedar or tile using recycled materials. Even metal roofs, the old standby for barns, have made a comeback with new colors, styles, and an unbeatable maintenance-free life expectancy.
Before you apply fertilizer and lime you should know your soil nutrient values. Soil tests can be done at most Land Grant Universities for little or no fee. Others avenues for testing are County Extension Agents and maybe some of the better garden nurseries. An easy way to take a soil sample is to take an old golf club. Keeping the grip in place cut the shaft at a 45 degree angle about 2′ down on the shaft. About 2″ up from the angled cut, cut out or notch 1/2 of the shaft circumference. By inserting this into the soil it will remove a 2″ core of soil. Take at least a dozen core samples from all over the lawn area. You will need about 1/3 -1/2 lb. of soil in total. You then remove the grass top from the core and place the remaining soil in a brown bag to be sent off for testing.