What Are the Best Soil Amendments

When doing gardening research, you often see a recommendation to add a soil amendment you may know little about. Here is a list of the most commonly used soil amendments and what they do and a few pointers for amending your garden soil. Always remember before adding any amendment to your soil to get your soil tested to establish the Ph of your soil. Ph is a measure of the acidity or alkalinity of your soil. A high Ph soil (above 7.0) is considered alkaline and a low Ph (below) 7.0 is considered acidic. Most amendments will alter your Ph level, for example, horse and cow manure can raise Ph, so monitor carefully. Some plants, like blueberries, need a soil Ph as low as 5.5, while other plants like lavender need a Ph as high as 8.0. Contact your local county agricultural extension office for more information about soil testing.

To lower Ph and make the soil more acidic sulfur, aluminum aulfate, and iron sulfate are added as amendments. They can all ruin your soil, so be sure to monitor the Ph carefully. In order to raise the Ph, and make your soil more alkaline, agricultural lime is often used and is best applied in the fall or winter. Overuse can also cause serious soil problems. If you need to slightly raise your soil PH, well-composted horse manure, bone meal, or rock dust will usually do the trick without being too harsh.

Other popular amendments are: Texas Green Sand, which is an iron potassium silicate that is naturally deposited in the sea. It contains potash, iron and trace minerals. It is best used with other fertilizers and will show immediate results. Application rates are from 20-40 lbs per 1000 square feet. Contains approximately 20% iron. Don't overuse it. Lava Sand however, cannot be overused and helps hold moisture in the soil and increases plant growth. It's a must for any organic gardening program. Decomposed Granite contains clay, to improve sandy soil structure, and potassium, and is used in addition to the other sands previously mentioned. Molasses granules and refined sugar helps control root-knot nematodes by increasing the natural microbes in the soil that feed on nematodes. Earthworm castings, although expensive, are rated highly as a soil conditioner and fertilizer.

Cottonseed meal (look for organic) is a great source for nitrogen and is often used around acid loving plants like gardenias or azaleas. Other organic sources of nitrogen to use as soil amendments are blood meal, fishmeal, and fish emulsion. Follow directions carefully.

If you use lots of manure, especially cow and horse manure, watch the level of phosphorous, calcium, magnesium, and soluble salts as an imbalance can occur over a long period of time. Dried manures are less apt to burn plants and the nutrients are more concentrated. The manure with the highest nitrogen content is bat guano, because it's been sitting in a cave and the rain hasn't washed out the nutrients. Dried chicken manure has lots of phosphorus and rates high for nitrogen along with rabbit manure. Dried cow manure is an excellent soil amendment and will contain fewer weed seeds than horse manure. Sheep and goat manure contain more organic matter than other manures. Always use a respirator when handling large quantities of manure because organisms that live in dried manure dust can cause damage to your lungs.

For more gardening information, visit: http://www.biglump.com/