By Harvey Goodman
It would be ideal if we could treat soil nutrition in much the same way as the federal government requires labeling of items in the supermarket, allowing us to see the minimum daily requirements of a particular nutrient and how much of it we’re getting in the food product.
Well, not entirely — the data is based on an average person weighing about 165 pounds at a height of about 5 feet, 10 inches. If you don’t fit that description, don’t be upset — most of us don’t.
There’s a similar problem with monitoring soil nutrition. The suggested treatment on a manufacturer’s product assumes soil of a particular quality, in an assumed growing zone, and under certain specific conditions involving gardening of a specific grouping of plants.
The best way to determine the particular nutrients for your lawn is to get a fertility analysis of the soil, which some nurseries provide. The simple test can show the nutrient level of your soil, and the nursery can suggest a specific fertilizer or a multiple fertilizer that is best for your garden.
Plants require 16 essential nutrients. Of these, three — hydrogen, carbon, and oxygen, the raw ingredients of all life on earth — are supplied by the air and water. The remaining 13 are supplied by the soil. This group is divided into three subgroups: primary nutrients (nitrogen, phosphorous and potassium); secondary nutrients (calcium, magnesium, and sulfur); and micronutrients (zinc, iron, manganese, copper, boron, molybdenum, and chlorine).
Nitrogen is an essential element for all living things. It is primarily used in the production of proteins, vital for proper growth and development. The element is made available to plants naturally through the decomposition of organic material, or by nitrogen-fixing bacteria, which have the ability to convert nitrogen in the air into nitrates.
Commercially available fertilizers often use synthetic forms of nitrogen in compounds such as ammonium sulfate, ammonium nitrate, and urea.
Phosphorus contributes to root growth, fruit development, seed formation, and disease resistance. Phosphate dissolves very slowly in the soil, so one treatment often can last for several years. The most common source of phosphorous is bone meal; as an extra bonus, bone meal also reduces soil acidity.
Potassium or potash strengthens stem and leaf growth. Also, as with phosphorus, the element aids in the resistance of plant disease. Potash is vital for flowering, seed, and root crops. Wood ash is a form of organic potash. Synthetic potash is available as compounds of potassium chloride or potassium sulfate.
Secondary nutrients, most often missing from the big three fertilizer mixture (nitrogen, potassium and phosphorus) are vital for proper plant growth and development.
Calcium enables plants to absorb nitrogen to synthesize proteins. Deformed fruits and vegetables can be one sign of calcium deficiency. Now you know why some gardeners use crushed eggshells in their compost.
Magnesium is essential for photosynthesis, the food-producing process in plants. Yellow leaves, or leaves with light green coloration, a condition known as chlorotic, may be a sign of magnesium deficiency.
There are several full-spectrum fertilizers that contain most of the essential secondary and micronutrients. Many of these products are powders that are dissolved in water and then applied to the garden.
Questions or comments on gardening and plant care can be addressed to: The Plant Doctor, Queens Publishing Company, 41-02 Bell Blvd. Bayside, N.Y. 11361 or e-mail: HYPERLINK Harvey.Goodman@worldnet.att.net
