A simple test can give you a fairly accurate reading of the pH (the acidity or alkalinity) of your soil. Here in the South West high deserts our soil is more on the alkaline side. However if your soil is clay, you will probably have a neutral or 6.0 to 7.0 reading.
pH requirements for plants:
For many years I have worked on improving my soil. It actually tests neutral, however it is heavy, heavy clay. Thousands of wheelbarrow loads of aged GOAT MANURE (I have used all types of manure, but I prefer the goat) has been added to the soil over the years. Now I have beautiful, loamy, crumbly soil that grows the most beautiful, nutrient dense vegetables. The best way to moderate your alkaline soil is to add 1/2 inch layer of composted manure over the garden and till in. If you have thick heavy clay soil, add 1/2 inch layer of sawdust and an inch layer of manure. The decomposition of the sawdust will help take up the excess nitrogen from the manure thus inhibiting the lush leaf growth and less fruiting caused by an abundance of nitrogen. Tilling in this excess amount will also help break up the heavy clay. I suggest letting your plants get a good 2 or 3 inch start, and then add a layer of compost as a thick mulch. I then carry it one step further and add a thick layer of old hay or straw. This is left in place after the plants die, breaking down over the winter and tilled under in the spring. Then the gardens are re-manured, sheet-composted, and mulched.
Adding a thick layer of mulch cuts down on the water needed for proper plant growth. The soil stays moist, allowing the roots to take in the needed water and nutrients. It insulates the soil, keeping the temperature even, and aids in the growth of plant roots. It provides food and habitat for earthworms and burrowing insects whose tunnels loosen and aerate the soil. Mulch keeps vegetables that sprawl on the ground: tomatoes, cucumbers, squash, melons, etc. from mildew or decay. Transplanted vegetables can be mulched soon after the plants are set. Weeding is kept to a minimum.
Many items can be used as a mulch; hay, straw, leaves, un-sprayed grass clippings, corn husks, shredded corn stalks, pine needles (great for acid loving plants like strawberries), sawdust, weeds, native grasses, and even wood chips raked up from your winter wood pile. If you haven't natural mulches available, try using dampened newspaper, shredded paper or cardboard. They will break down over time, adding organic matter to the soil.