Essential Plant Nutrients

Nitrogen, phosphorus, and potassium are all needed for normal plant growth. If soil is deficient in any essential nutrient, it can have adverse affects on the health of plants.

What are the various elements of plant nutrition; and their uses? The three essential elements and their effect on plant growth are: Nitrogen: this element enters into the structure of protoplasm, chlorophyll, and various plant foods; it is needed for both the vegetative and reproductive stages of growth; its use is usually manifested by an increase in vegetative growth. Phosphorus: it is essential to cell division and for the formation of nucleoproteins; it aids root development; hastens maturity, or stiffens tissues; and stimulates flower and seed production. Potash: necessary for the manufacture and translocation of starches and sugar; it is a general conditioner, overcoming succulence and brittleness, hastening maturity and seed production, and aiding in root development.

Nitrogen

How can I recognize nitrogen deficiency? The whole plant is dwarfed and the older leaves turn from green to yellow, and then to brown, and remain attached to the plant. Stalks are slender, and few new stalks develop.

How can nitrogen deficiency be corrected? Apply ammonium sulfate at 3/4 lb. or sodium nitrate at 1 lb. per 100 sq. ft. Ammonium sulfate tends to make soil more acid; sodium nitrate makes it more alkaline. A complete fertilizer (as 4-12-4, or 5-10-5) will correct the deficiency of nitrogen as well as supply phosphorus and potash.

What is lacking in my garden soil, since the carrots I raise, though of good size, are almost tasteless and colorless? Nitrogen is lacking; a complete fertilizer (4-12-4, or 5-10-5) at 4 lbs. per 100 sq. ft. will correct this.

What causes yellowing of foliage? It may be due to poor drainage, or to lack of nitrogen.

What shall I do for soil that grows annuals and perennials too large and weedy, but weak stemmed? Probably too much nitrogen in the soil and not enough phosphorus and potassium. Use a 0-10-10 fertilizer, or something similar, at 2 lbs. per 100 sq. ft. for one or two applications. Excess nitrogen usually disappears rapidly.

All foliage and few flowers is my trouble What is wrong? Too much nitrogen and probably not enough phosphorus and potash; add both in the form of a 0-10-10 fertilizer (or similar) at a rate of 2 lbs. per 100 sq. ft.

What causes an excess of nitrogen in the soil? Have added 10 lbs of bone meal in a 35-sq.-ft. bed for annuals, and some dehydrated manure (100 lbs) for spring. Excess nitrogen, or the symptoms of excess nitrogen, may be brought about through the excessive use of nitrogenous fertilizers, high nitrogen complete fertilizers, or a deficiency of phosphorus and potash. The amount of manure you have applied constitutes over-fertilization. Bone meal usually is locked up in an insoluble form and has little effect on growth.

Phosphorus

How can I recognize phosphorus deficiency? The whole plant is dwarfed, but the foliage is a dark, dull green; leaf stem (petiole) often turns purple. Areas between veins on leaf sometimes turn purple, and leaf margins often turn yellow. Loss of lower foliage follows.

How can phosphorus deficiency be corrected? Apply treble superphosphate or superphosphate, at 5 lbs. per 100 sq. ft.

Potash

How can I recognize potash (potassium) deficiency? Lower foliage begins to turn yellow at leaf margin; leaf often mottled yellow and green in between veins; margins of leaves turn brown and foliage drops from plant; plant generally stunted.

How can potash (potassium) deficiency be corrected? Apply muriate of potash or sulfate of potash, 1 lb. per 100 sq. ft.

What fertilizer should I use to encourage fruits and vegetable roots? Plants grow all to tops. Withhold nitrogen and increase the proportion of phosphorus and potash in the mixture. Use a 2-10-10 fertilizer for a few years, adding additional nitrogen only where, and as, needed.

Some soils tend to develop barren vines. What is lacking? This is usually the result of too little phosphorus and potash.

What does soil lack that produces an abundant crop of any vegetable above ground, but no root vegetables such as potatoes, beets, turnips, or salsify? Phosphorus and potassium are probably deficient in this soil.

My garden is made of filled earth and has a large amount of street sweepings in it, high in leaf mold. All root crops fail; beans and corn are only crops that succeed. Why? Lack of phosphorus and potassium may cause the trouble. However, all fertilizer elements are lacking in leaf mold. Try a complete fertilizer.