Tag: phosphorus

Potassium deficiency

Potassium deficiency

Potassium (K) is one of the essential nutrients and is taken up in significant amounts by crops. Potassium is vital to photosynthesis, protein synthesis and many other functions in plants. It’s classified as a macronutrient, as are nitrogen (N) and phosphorus (P). Plants take up K in its ionic form (K+).

While potassium (K) doesn’t constitute any plant structures or compounds, it plays a part in many important regulatory roles in the plant. It’s essential in nearly all processes needed to sustain plant growth and reproduction, including:

  • photosynthesis
  • translocation of photosynthates
  • plant respiration
  • protein synthesis
  • control of ionic balance
  • breakdown of carbohydrates, which provides energy for plant growth
  • regulation of plant stomata and water use
  • activation of plant enzymes
  • disease resistance and recovery
  • turgor
  • stress tolerance, including extreme weather conditions

Perhaps K’s most important function in the plant is that it can activate at least 80 enzymes that regulate the rates of major plant growth reactions. K also influences water-use efficiency. The process of opening and closing of plant leaf pores, called stomates, is regulated by K concentration in the guard cells, which surround the stomates. When stomates open, large quantities of K move from the surrounding cells into the guard cells. As K moves out of the guard cells into surrounding cells, stomates close, therefore K plays a key role in the process plants use to conserve water. Unlike nitrogen (N) and phosphorus (P), the other primary nutrients, K doesn’t form organic compounds in the plant. Its primary function is related to ionic strength of solutions inside plant cells. Potassium plays a key part in increasing yields and controlling disease because it improves a crop’s winter hardiness. It allows crops to get a quicker start in the spring and increases vigor so growth can continue throughout the growing season. Even though the period of K uptake varies with different plants, it’s still vital to maintain adequate K fertility levels in the soil because soil K doesn’t move much, except in sand or organic soils. Unlike N and some other nutrients, K tends to remain where fertilization puts it. When it does move, it’s mainly by diffusion and is always slow. Plants generally absorb the majority of their K at an earlier growth stage than they do N and P. Experiments on K uptake by corn have shown that 70 to 80 percent can absorb by silking time, and 100 percent at three to four weeks after silking. K translocation from the leaves and stems to the grain occurs in much smaller amounts than for P and N. The grain formation period is apparently not a critical one for the supply and uptake of K. Plants deficient in K don’t grow as robustly and are less resistant to drought, excess water, and high and low temperatures. They’re also more vulnerable to pests, diseases and nematode attacks. Potassium is also known as the “quality nutrient” because of its important effects on factors such as size, shape, color, taste, shelf life, fiber quality and other qualitative measurements. Potassium-deficiency symptoms show up in many ways. One of the most common K hunger signs is scorching or firing along leaf margins. Firing first appears on older leaves in most plants, especially grasses. Newer leaves will show hunger signs first on certain plants and under certain conditions. In addition to growing slowly, K-deficient plants’ root systems develop poorly and have weak stalks. Lodging is also common.   Symptoms of deficiency can vary across crop species, but similarities exist for how nutrient insufficiency impacts plant tissue color and appearance. Nutrient deficiencies are commonly associated with the physical location on the plant
(i.e., whether the symptoms are primarily observed on older versus newly formed plant tissue), but these symptoms can spread as the severity of the deficiency progresses.

Phosphorus deficiency

Phosphorus deficiency

One of three primary nutrients, phosphorus (P) is essential for plant growth. No other nutrient can be substituted for P — a plant must access it to complete its normal production cycle.

Phosphorus is a vital component of adenosine triphosphate (ATP), the “energy unit” of plants. ATP forms during photosynthesis, has P in its structure, and processes from the beginning of seedling growth through to the formation of grain and maturity.

The general health and vigor of all plants requires P. Some specific growth factors associated with P include stimulated root development, increased stalk and stem strength, improved flower formation and seed production, more uniform and earlier crop maturity, increased nitrogen (N)-fixing capacity of legumes, improvements in crop quality, and increased resistance to plant diseases.

Phosphorus deficiency is more difficult to diagnose than a deficiency of N or potassium (K). Crops usually display no obvious symptoms of P deficiency other than a general stunting of the plant during early growth, and by the time a visual deficiency is recognized, it may be too late to correct in annual crops.

Some crops, such as corn, tend to show an abnormal discoloration when P is deficient. The plants are usually dark bluish-green in color, with leaves and stem becoming purplish. The genetic makeup of the plant influences the degree of purple, and some hybrids show much greater discoloration than others. The purplish color results from the accumulation of sugars, which favors the synthesis of anthocyanin (a purplish pigment) that occurs in the leaves of the plant.

Phosphorus is highly mobile in plants and, when deficient, may translocate from old plant tissue to young, actively growing areas. Consequently, early vegetative responses to P are often observed. As a plant matures, P translocates into the fruiting areas of the plant, where the formation of seeds and fruit requires high energy. Phosphorus deficiencies late in the growing season affect both seed development and normal crop maturity. The percentage of the total amount of each nutrient taken up is higher for P late in the growing season than for either N or K.

 

Symptoms of deficiency can vary across crop species, but similarities exist for how nutrient insufficiency impacts plant tissue color and appearance. Nutrient deficiencies are commonly associated with the physical location on the plant
(i.e., whether the symptoms are primarily observed on older versus newly formed plant tissue), but these symptoms can spread as the severity of the deficiency progresses.

 

 

 

 

 

Molybdenum deficiency

Molybdenum deficiency

Molybdenum (Mo) is a trace element found in the soil and is required for the synthesis and activity of the enzyme nitrate reductase. Molybdenum is vital for the process of symbiotic nitrogen (N) fixation by Rhizobia bacteria in legume root modules. Considering Mo’s importance in optimizing plant growth, it’s fortunate that Mo deficiencies are relatively rare in most agricultural cropping areas.

Plants take up molybdenum (Mo) as the MoO42- anion. It’s required for the synthesis and activity of the enzyme nitrate reductase and. vital for the process of symbiotic nitrogen (N) fixation by Rhizobia bacteria in root nodules. It’s also needed to convert inorganic phosphorus (P) to organic forms in the plant.

Molybdenum deficiencies show up as general yellowing or stunting of the plant, and more specifically in the marginal scorching and cupping or rolling of leaves. An Mo deficiency can also cause N-deficiency symptoms in legume crops such as soybeans and alfalfa, because soil bacteria growing symbiotically in legume root nodules must have Mo to help fix N from the air.

Molybdenum deficiencies occur mainly in acidic, sandy soils in humid regions. Sandy soils, in particular, more typically lack Mo than finer-textured soils. Molybdenum becomes more available as soil pH goes up, the opposite of other micronutrients. Since Mo becomes more available with increasing pH, liming will correct a deficiency if soil contains enough of the nutrient. However, seed treatment is the most common way of correcting Mo deficiency because only very small amounts of the nutrient are required.

Heavy P applications increase Mo uptake by plants, while heavy sulfur (S) applications decrease Mo uptake. Applying heavy amounts of S-containing fertilizer on soils with a borderline Mo level may induce Mo deficiency.

Excessive Mo is toxic, especially to grazing animals. Cattle eating forage with excessive Mo content may develop severe diarrhea.

 

 

Symptoms of deficiency can vary across crop species, but similarities exist for how nutrient insufficiency impacts plant tissue color and appearance. Nutrient deficiencies are commonly associated with the physical location on the plant

(i.e., whether the symptoms are primarily observed on older versus newly formed plant tissue), but these symptoms can spread as the severity of the deficiency progresses.

Iron deficiency

Iron deficiency

Iron (Fe) is essential for crop growth and food production. Plants take up Fe as the ferrous (Fe2+) cation. Iron is a component of many enzymes associated with energy transfer, nitrogen reduction and fixation, and lignin formation.

Iron (Fe) is involved in the production of chlorophyll, and Fe chlorosis is easily recognized on Fe-sensitive crops growing on calcareous soils. Iron also composes many enzymes associated with energy transfer, nitrogen reduction and fixation, and lignin formation. Iron is associated with sulfur in plants to form compounds that catalyze other reactions.

Iron deficiencies are mainly manifested in yellowed leaves that result from low levels of chlorophyll. Leaf yellowing first appears on the younger, upper leaves in interveinal tissues. Severe Fe deficiencies cause leaves to turn completely yellow or almost white, and then brown as leaves die.

Iron deficiencies occur mainly in calcareous (high pH) soils, although some acidic, sandy soils low in organic matter also may be Fe-deficient. Cool, wet weather enhances Fe deficiencies, especially on soils with marginal levels of available Fe. Poorly aerated or highly compacted land also reduces Fe uptake by plants. Uptake of Fe decreases with increased soil pH, and is adversely affected by high levels of available phosphorus, manganese and zinc in the ground.

Since soil applications of most Fe sources are generally ineffective for correcting Fe deficiencies in crops, foliar sprays are the recommended method. The application rate should be high enough to wet the foliage, so spraying a 3 to 4 percent FeSO4 solution at 20 to 40 gallons per acre is typical. Including a sticker-spreader agent in the spray helps improve its adherence to the plant foliage for increased Fe absorption by the plant. Even so, correcting chlorosis may require more than one foliar Fe application.

 

 

Symptoms of deficiency can vary across crop species, but similarities exist for how nutrient insufficiency impacts plant tissue color and appearance. Nutrient deficiencies are commonly associated with the physical location on the plant
(i.e., whether the symptoms are primarily observed on older versus newly formed plant tissue), but these symptoms can spread as the severity of the deficiency progresses.

 

Organic Fertilizers

Sooner or later, every gardener discovers that for good results — whether in the vegetable garden, perennial border, or lawn — replenishing soil nutrients is necessary. And one of the key choices is whether to use organic or synthetic fertilizers. Synthetic fertilizers are manufactured. Organic fertilizers are derived from plants and animals, and from naturally occurring mineral fertilizers.

Why Use Organic Fertilizers?

One advantage of organic fertilizers is that their nutrients are doled out as a steady diet in sync with plant needs. Because the nutrients come from natural sources, a portion of them may be temporarily unavailable to plants until released by a combination of warmth and moisture — the same conditions plants need to grow. Released slowly, the nutrients from organic fertilizers are unlikely to burn plant roots or be leached away by water. And a single application may last a whole growing season.

You also might choose organic fertilizers for philosophical or environmental reasons. Organic fertilizers generally place fewer demands on energy resources, and they offer opportunities to recycle “garbage”.

The more concentrated a fertilizer (even an organic one), the less organic matter it contains. Fertilizers containing high concentrations of nitrogen, when used alone, can actually deplete soil organic matter, so if you use any such fertilizer, apply plenty of bulky organic matter, too. Dig materials such as straw, peat, compost, and leaves into the soil, or lay them on as mulch.

Naturally occurring mineral fertilizers are organic in the “not-synthetic” sense, but because they don’t contain organic matter, they’re not included in this list. Among them are Chilean nitrate, rock phosphate, greensand, and sulfate of potash magnesia.

Synthetic fertilizers do have some advantages. They cost less, are easier to transport, and are more uniform in nutrient content. All but controlled-release synthetic fertilizers are more quickly available to plants than organic fertilizers.

Why fertilize? Fertilizers are necessary make up for nutrients that are naturally carried down into the groundwater by rainfall, carried off into the air as gases, and carried into the kitchen by you. At least 16 nutrient elements are necessary for plant growth, but plants need three — nitrogen, phosphorus, and potassium (referred to by the elemental symbols N, P, and K) — in relatively large quantities. Most soils contain large reserves of the other 13 nutrients — especially calcium, magnesium, sulfur, iron, zinc, and manganese — that might also hitchhike along when you fertilize with “the big three.”

The only way to know for sure if your garden requires fertilizers is to have the soil tested. The cooperative extension services in most states test garden soil for a nominal fee. Also check telephone directories for “soil testing laboratories.”

When to Apply. The best times to apply organic fertilizers are early spring and fall — or even a few months — before planting, because that allows time for soil microbes to digest the organic matter and transform nutrients into forms plants can use.

How to Apply. When you apply organic fertilizers, there’s no need to dig them deep into the soil. Plants’s feeder roots are mostly near the soil surface, and low oxygen levels deep in the soil would retard microbial growth, slowing nutrient release from organic fertilizers. Make an exception to that no-dig rule if a soil test shows that phosphorus levels are low. This nutrient moves very slowly, so the only way to spread it quickly through the root zone is to mix it into the top 6 to 12 inches of soil.

Always wear a dust mask when you apply bonemeal, guano, or any other type of fertilizer that’s dusty. All dusts are potential lung irritants.

How Much to Apply. The actual amount to apply will vary, depending on the results of a soil test and the rate of nutrient release from a particular fertilizer. A rough rule is: Apply approximately 2 pounds of actual nitrogen (100 pounds of 10-10-10 contains 10 pounds of “actual” nitrogen) per 1,000 square feet, or 0.2 pounds per 100 square feet. Apply the other key nutrients plants take from soil — phosphorus and potassium — at about one-tenth this rate, unless a soil test specifies otherwise.

In catalogs and garden centers, you can find many different kinds of organic fertilizers. Other kinds are either custom blends, or materials that are available in limited quantities or only regionally. All fit into one of the basic categories — plant, animal, compost, or manure — that are further described below.

Plant Substances or By-products. Fertilizers that are plant substances or by-products are often rich in nitrogen, sometimes in potassium. These fertilizers can be considered renewable resources, but you should take into account the resources that may have been needed to grow as well as process or transport them. Some, such as beet pulp and cottonseed meal, are by-products of other industries.

  • Alfalfa meal and pellets contain nitrogen, phosphorus, and potassium. Some rose growers report good results when it is used as a mulch.
  • The dried, shredded remains of sugar beets after the juices and sugars are extracted are sold as organic fertilizer. They are rich in nitrogen.
  • Corn gluten is a high-nitrogen fertilizer with the unique ability to inhibit germination of seeds. With it you can feed your lawn and prevent crabgrass at the same time.
  • Cottonseed meal is made from the remains of cotton seeds after the oil is pressed out. It is a high-nitrogen fertilizer, but some growers have concerns about pesticide contamination of the meal. Cotton is a heavily sprayed crop, but pesticide-free cottonseed meal is available.
  • The extracts or pulverized parts of several seaweeds and kelp are good sources of minerals, potassium, and sometimes nitrogen. Follow application directions carefully when spraying on leaves, because sea plants can affect plant growth when sprayed directly on leaves.
  • Soybean meal is a high-nitrogen fertilizer that’s very similar to its better-known cousin, cottonseed meal. For the best price, look for it at animal feed-supply stores.

Animal processing by-products. Industries such as dairy farming and meat processing generate waste materials that are dried or minimally processed into fertilizers. None of these materials is derived from “certified organic” animals.

  • Blood meal is a rich source of nitrogen that is quickly available, so use with care.
  • Bonemeal is a rich source of phosphorus and calcium, and it supplies moderate amounts of nitrogen. “Steamed” bonemeal has less nitrogen but somewhat faster nutrient availability than “raw” bonemeal.
  • Fish products can be fairly rich in nitrogen, phosphorus, and potassium, but read the labels because nutrient concentrations vary.

Composts. These are the “Cadillacs” of organic fertilizers. Although making compost from a variety of raw materials is possible, the finished products are remarkably similar in their final concentrations of nitrogen, phosphorus, and potassium. Composts generally contain a good balance and wide spectrum of nutrients, and they’re rich in humus — so rich in humus, in fact, that their actual nutrient concentrations are relatively low.

Composts are available commercially or can be homemade. They can be used along with other fertilizers. Ingredients in commercial composts include various kinds of animal manures and lawn and garden wastes. Homemade fertilizer is a way to deal with “waste” and make fertilizer simultaneously — and you always know what ingredients went into the finished product.

Manures. Manures used as organic fertilizers are derived from humans, animals, and in one case, insects; manures are available fresh or dried; however, use composted manure whenever possible.

The composition of various manures vary not only with the kind of animal source, but also with the age of the animal, the bedding, and method of manure storage and application.

  • Cow manure is low in nutrients, but plants can absorb them moderately quickly.
  • Manure from seabirds or bats are rich in nutrients, but not in organic matter. Highly soluble and quickly available nutrients are useful early in season to stimulate vegetative growth. But be careful: high-nitrogen guanos may burn plants. Several types are available: Texan bat (10-4-2), Ancient seabird (0-12-1), and Peruvian seabird (14-11-2) are examples. All guanos can be mixed with water, steeped, and applied as a liquid.
  • Commercially available insect manure, cricket manure, is relatively nutrient-rich.
  • Poultry manure is relatively high in nitrogen, phosphorus, and potassium.
  • Composted sludges are rich in slowly available nitrogen. If industrial wastes are included, contaminants, such as heavy metals, are present. Though approved for vegetable gardening by the Environmental Protection Agency, these fertilizers are not acceptable for organic gardening.
  • Worm castings are similar to compost in their composition and are equally easy to produce at home. Because nutrient levels are so low in worm castings, they are — like compost — considered more a soil amendment than a fertilizer.

Much of the benefit of organic fertilizers comes not from the nutrients, but from the organic matter — the bulk — the fertilizers contain. Among other benefits, organic matter helps soils hold water and air, makes nutrients already in the soil more available, and helps prevent diseases.

Don’t spurn organic fertilizers that are low in nutrients, because they’re rich in organic matter that turns to valuable humus in the soil.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Nutrient Deficiencies in Plants

Nutrient Deficiencies in Plants

Sometimes plants look unhealthy and we assume they have been attacked by pests. This could however be early signs of nutrient deficiency.

If plants do not receive adequate proportion of essential minerals or they fail to thrive despite of proper growing conditions it signifies they are suffering from malnutrition. There are various minerals required for proper growth and health of a plant. Excess of these nutrients can be harmful as well and may show toxicity symptoms. This implies you need to be very careful while feeding plants with essential minerals and nutrients, as both excess and lack of them can be a cause of adverse effects.

Nutrients are divided in 2 categories – micronutrients and macronutrients. Minerals required in small traces are called micronutrients, while those required in large amounts are termed as macronutrients. Following tables give information about various nutrients, their deficiency & toxicity symptoms, and treatment for respective nutrient deficiency:

FOR MICRONUTRIENTS:

NUTRIENT AND FUNCTION DEFICIENCY SYMPTOMS TOXICITY SYMPTOMS TREATMENT FOR DEFICIENCY
BORON: stimulates cell wall and flower formation, cell division and pollination; enables sugar transportation. Rotting of roots; death of growing points; uneven ripening; young leaves turn red, brown or scorched; death of buds. Margins and leaf tips will turn brown and die. Apply household borax. This should be done at a rate of 1 tablespoon of borax to 12 quarts of water.
IRON: necessary for legume nitrogen fixation; regulates respiration of plant cells; helps in chlorophyll formation; used for enzymatic activity. Necrotic spots; discoloring of leaves; young leaves develop chlorosis; yellowing of veins in young leaves; poor colored fruits. Bronzing of leaves with brown spots. Add chelated iron, bone meal, iron sulfate or inorganic amendments.
COPPER: regulates cell wall construction, cell growth and division; stimulate enzymatic activity required for nitrogen and carbohydrate metabolism. Brown area near tips of a leaf; small leaves with necrotic spots; root growth stops; leaves are dark green with stunted plants. Root growth stops; an iron deficiencymay be induced. Apply calcium rich fertilizers like calcium sulfate, foliar application of copper; treatment of seeds with copper compounds.
MANGANESE: stimulate enzymatic activity; promote energy cycle; helps in chloroplast production; enhances root growth and fruit development. Leaves show scorching and have reduced width; total yellowing of young leaves or between leaf veins. Shows iron deficiency symptoms; brown spots on older leaves; blotchy leaf tissue. Add manganese sulfate inorganic amendments.
MOLYBDENUM: helps innitrogen fixation and in reducing absorbed nitrates into ammonia; required for protein synthesis and enhances photosynthesis. Problem in brassica family like cauliflower showing elongated twisted leaves; head can fail to form; restricted flower formation Not so common. Excess intake will appear as copper/iron deficiency. Add lime before sowing seeds.
ZINC: used in synthesis of chlorophyll; stimulates enzymatic activity; essential for hormone balance especially auxin. New leaves are small and yellow; shoots may show resetting followed by dieback; short internodes; missing leaf blades; terminal leaves may be rosetted. Very rare. Shows signs of iron deficiency. Use aged organic manure, acidity generating fertilizers and organic compounds like zinc chelate etc.

FOR MACRONUTRIENTS:

NUTRIENT AND FUNCTION DEFICIENCY SYMPTOMS TOXICITY SYMPTOMS TREATMENT FOR DEFICIENCY
NITROGEN: responsible for production of nucleic acids and proteins to carry out reproduction and cell division. Major part of chlorophyll. Yellowing of older leaves; new leaves are smaller in size; branching is reduced; plants mature early and get stunted Plants become dark green in color and are susceptible to lodging; plants are prone to drought stress; lack of fruit set; poor secondary shoot development. Short term: spray with fish emulsion; apply high nitrogen fertilizers.Long term: mulching with organic matter; apply aged compost; use soybean meal and manure once in spring.
PHOSPHOROUS: required for cell division, sugar and starch formation, and energy transfer. Strengthen stems; responsible for flowering and fruiting; helps plants to act as resistant to diseases and pests. Plant growth slows down; old leaves turn dark green or reddish – purple; leaf tips look burnt; thin stems Shows visual deficiency of nutrients like zinc, iron and manganese. Short term: spray with fish emulsion; apply aged compost and apply phosphorous rich fertilizers like super phosphate or bone meal.Long term: mix rock phosphate in soil.
CALCIUM: responsible for cell wall construction, cell growth, leaf and root development. New leaves are irregularly shaped or distorted; blossom-end rot in tomatoes; brown color of growing leaves and roots; tip burn in some plants like cabbage; premature shedding of fruits; leaves may stick together High calcium will cause precipitation of many micro-nutrients as a result they remain unavailable to plant; plant may showmagnesium deficiency symptoms. Add organic matter, agricultural lime to acidic soils.
POTASSIUM: responsible for activation of enzymes, stomata opening, root development, formation of sugar, electrolyte balance and transpiration. Also increases resistance of plants to diseases. Sick looking plants; curling of leaves; old leaves turn yellow and look scorched; undersized fruits; leaves may turn brown; weak branches and stems; poor fruiting and flowering Cause nitrogen deficiency in plants; plants exhibitmagnesium and calcium deficiencysymptoms. Short term: spray with fish emulsion; use fertilizers like sulphate of potash, tomato feed.Long term: apply seawmeed, granite dust, manure or greensand.Hardwood ashes can be applied anytime.
MAGNESIUM: helps in production of ATP and synthesis of chlorophyll. Responsible for enzymatic actions. Older leaves turn yellow while leaf veins remain green; slow growth; leaf tip gets twisted. Shows sign of calcium orpotassium deficiency; necrotic spots in old leaves; veins in older leaves may turn brown Apply foliar magnesium.
SULFUR: acts as enzyme activator and coenzyme; responsible for root growth. Shoots are stunted; new leaves are yellow in color; roots and stems appear small. Premature ageing. Add sulfur or potassium sulfate.

Above given treatments will help you to maintain a healthy crops, blooming fields, bringing you pride and peace.

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