You do not need a soil test to tell you organic matter is good for your garden. Perhaps the biggest landscape mistake is not addressing the health of the soil. With all the soil tests that I have read in the last five years of being an educator, tests find around 1 to 2 percent organic matter.
Experts would prefer this number be at 10 percent. Adding organic matter in the form of compost can prevent nutrients from leaching, improve soil texture for root growth and can prevent some diseases in the landscape.
One must think of gardening beyond the plants, as you are also growing the soil profile. The soil is teeming with bacteria, fungus, mychoorizae (plant root fungi) and it needs organic matter to feed on. In nature, organic matter is added to the soil through fallen leaves, dead plants, animal droppings, ect. This allows plants' nutrients to make food and a very happy home for the roots. Adding compost each year can be very beneficial for an amazing garden of flowers and vegetables.
I do have to be a plant nerd and say you should still get a soil test to know the pH of your soil. However, this endeavor is best addressed during the fall. Here is the rundown of some composts for the garden.
Mushroom Compostis mycelium (vegetative white hyphae of mushrooms) and their food. Their food can be made up of wheat, straw, peat moss, chicken manure, and meal from grains, etc. According to Oregon State University, mushroom compost should be used as a side dressing to perennials, trees and shrubs, but is not as beneficial to a garden bed of germinating seeds. The soluble salts are too concentrated for germinating seeds and young plants, and may kill or stunt growth.
Homeowner's Backyard Compost,also known as gardener's gold, can be made up yard trimmings, food wastes, straw, and leaves. The composter has full control over what is used to make the compost. However, homeowners can also get compost from the city that is made up of lawn trimmings, fall leaves and city garden refuse. Most compost from cities is safe to use in food gardening but may have some seeds.
Composted poultry manureis active slow-release fertilizer. Composted poultry has high salt content, but if incorporated into the soil, 6 to 10 inches can be used on seedlings and new plants. The general rule of thumb is that if more than 50 percent bedding is included, apply 1.5 inches; if less than 50 percent, apply half of an inch to the garden space.
Actual Soil Test and Recommendations
pH 7.4 (6.4-7.0) Elevated
Phosphorus (P) 853 (35-45) Elevated
Potassium (K) 814 (350-450) Elevated
Organic Matter 4.0 Adequate
Your soil pH is rather elevated and would benefit from reduction. Reducing the soil pH is going to take a lot of dedicated work, but it is worth the effort, if done properly. Alkaline soil can be corrected by applying sulfur at the rate of 20-25 pounds per 1000 square feet. Individual applications of sulfur should not exceed 5 pounds over 1000 square feet. The best time for applications is in the spring (two or more weeks prior to planting) and fall, preferably immediately prior to a rain event. You may need 2-4 applications over a period of 2-4 years to achieve the desired results. The pH level in the soil should be monitored on an annual basis once a pH-adjustment program with sulfur is initiated. If you chose pH reduction and send further samples to evaluate the progress; please refer to this report by date and work order number. Acidifying fertilizers such as sulfur coated urea or time released urea; can be used in your fertilization program. DO NOT ADD ANY LIMING AGENTS.
*I do not recommend the use of aluminum sulfate as this can cause build up of aluminum in the soil.
Your phosphorus and potassium are greater than the desired value for proper plant growth. There is not a good way to reduce these elements; however, with the reduction of soil pH the plants will naturally utilize these elements.
Annual applications of nitrogen at the rate of 1 – 2 pound per 500 square feet are necessary for healthier plants. It is best to split the applications into 2 or 3 equal applications during the growing season.