It is a good idea to have your soil tested to know the nutrients needed for plants to grow in your garden. Soil testing results will provide the information you need to know how much lime and fertilizer your plants need.
Sixteen Nutrients Needed for Plants to Grow
Everyone knows the basic needs that make plants grow:
- Suitable temperatures
Water and air provide plants with three necessary nutrients: carbon, hydrogen and oxygen, however, in the soil there are thirteen more nutrients needed for plants to grow. This is why a soil test can help you grow healthy, verdant plants. Once you have your soil report, you'll be able to provide the specific nutrients it lacks.
Generally these nutrients are divided into two groups, and are arranged according to the quantities needed by plants.
- Nitrogen - promotes leaf and stem growth. When the soil lacks sufficient nitrogen, growth is reduced and leaves turn a pale yellowish-green. When soil is cold and wet, nitrogen supplies in the soil aren't as available to the plants. Too much nitrogen in the soil can lead to a potassium deficiency.
- Phosphorus - this nutrient is critical in the germination and growth of seeds, flowers, fruit, and roots. When phosphorus is deficient, growth is reduced and leaves fall off prematurely. Plants lacking phosphorus produce dull, bluish-green leaves that turn a purplish or bronze color with brown edges. Just like nitrogen, too much phosphorus may lead to potassium deficiency.
- Potassium - promotes hearty, disease-resistance growth. Without adequate potassium, growth is stunted and leaves grow close together. Leaf tips and edges become brown and edges curl. Too much potassium in your soil can lead to calcium and magnesium deficiencies.
- Calcium - a vital component in cell walls of plants, calcium is essential for root growth. Without adequate calcium roots develop poorly and leaves become distorted and often turn brown.
- Magnesium - this nutrient is necessary for chlorophyll production and plays a vital role in most enzyme reactions. If your soil lacks the proper amount of magnesium, the deficiency causes varying symptoms in different plants. Most often symptoms include things like yellowing leaves that may suddenly fall off without withering. Too much magnesium could cause a calcium deficiency.
- Sulfur - A necessary nutrient for chlorophyll formation. Too little sulfur produces slow growth that generates small round leaves that are stiff and brittle. Leaves drop and tip buds die.
- Iron - This trace element is needed for chlorophyll formation and oxygen transfer. Without adequate iron, leaves yellow (but leaf veins remain green). If you add too much lime to your soil, it can lead to an iron deficiency.
- Manganese - works as a channel for a variety of enzymes and is essential for chlorophyll formation. Too little manganese causes a variety of indicators depending on the type of plant. The most common signs include yellowing leaves with green veins or grayish-white specks that appear on the leaves. Too much manganese may deplete iron in the soil and cause symptoms similar to those exhibited with a lack of manganese.
- Boron - works as a vehicle for the interchange of sugars, for reproduction, and for cell intake of water. Without adequate boron your plants will be distorted with hollow stems and malformed fruit. Other symptoms include scorched, curled and sometimes mottled leaves.
- Zinc - important for the production of proteins. This nutrient affects how big plants grow and whether or not they mature. Lack of zinc produces less fruit and brings about yellowing of leaves between veins often accompanied by purple or dead spots with small, deformed leaves growing close together.
- Copper - this is another nutrient important for the production of proteins and plays and important role in reproduction. If your plants don't get enough copper they will display bluish-green leaves that might wither or never unfold. Lack of copper may also form rosettes on growing tips.
- Molybdenum -- this nutrient is vital to nitrate enzymes and the formation of root nodules in beans and peas. Without adequate supplies of molybdenum, leaves produce yellow mottling and dead spots and often growing tips are distorted or killed
- Chlorine - Lack of the right amount of chlorine in you soil might affect carbohydrate metabolism and photosynthesis. This deficiency leads to stubby roots and wilting.
Don't try to guess what your soil needs. A soil test can tell you which of the above nutrients are lacking. The test chemically removes the elements from the soil sample and measures for plant available content. The amount of existing nutrients in the sample will determine what fertilizer to use and how much to apply. Along with this, the soil test checks the soil's pH (acidity or alkalinity), humic matter and exchangeable acidity. Soil pH affects the availability of nutrients. In general, macronutrients tend to be less in low pH soils while micronutrients are often lacking in soils with higher pH. From the analysis, you will learn whether or not lime should be applied to your soil, and if so in what quantity. Lime will make the soil less acidic and is also a source of calcium and magnesium.