Category: Nutrient Deficiencies

Boron Deficiency

Boron deficiency

 

 

 

Boron (B) exists primarily in soil solutions as the BO33- anion — the form commonly taken up by plants. One of the most important micronutrients affecting membrane stability, B supports the structural and functional integrity of plant cell membranes. Interestingly, while higher plants require B, animals, fungi and microorganisms don’t.

Micronutrients like Boron (B) are as important as the primary and secondary nutrients in plant nutrition. However, the amounts of micronutrients required for optimum nutrition are much lower. Micronutrient deficiencies are widespread because of increased nutrient demands from the more intensive cropping practices.

A primary function of B relates to cell wall formation, so B-deficient plants may be stunted. Sugar transport in plants, flower retention, and pollen formation and germination also are affected by B. Seed and grain production are reduced with low B supply. Boron-deficiency symptoms first appear at the growing points. This results in a stunted appearance (rosetting); barren ears due to poor pollination; hollow stems and fruit (hollow heart); brittle, discolored leaves, and loss of fruiting bodies. Boron deficiencies mainly occur in acidic, sandy soils in regions of high rainfall and in those with low soil organic matter. Borate ions are mobile in soil and can leach from the root zone. Boron deficiencies are more pronounced during drought periods, when root activity is restricted.

Recommended application rates of B are rather low (0.5 to 2 pounds per acres), but growers should follow them carefully, since the range between B deficiency and toxicity in most plants is narrow. Uniform application of B in the field is very important for that reason.

Soil tests and plant analyses make excellent diagnostic tools to monitor the micronutrient status of soils and crops. Helpfully, deficiency symptoms of these nutrients are highly visible in most economic crops, so growers can readily identify them and begin managing the problem. Micronutrient recommendations are based on soil and plant tissue analyses, the type of crop and expected yield, management level, and research results.

Include soil tests in B fertilization programs, first to assess the level of available B and later to determine possible residual effects (buildup). The most common soil test for B is the hot-water-soluble test. This test is more difficult to conduct than most other micronutrient soil tests, but most B-response data have been correlated with it.

 

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.


16 ESSENTIAL NUTRIENTS IN CROP DEVELOPMENT

Sixteen plant food nutrients are essential for proper crop development. Each is equally important to the plant, yet each is required in vastly different amounts. These differences have led to the grouping of these essential elements into three categories; primary (macro) nutrients, secondary nutrients, and micronutrients.

PRIMARY (MACRO) NUTRIENTS

Primary (macro) nutrients are nitrogen, phosphorus, and potassium. They are the most frequently required in a crop fertilization program. Also, they are need in the greatest total quantity by plants as fertilizer.

NITROGEN

  • Necessary for formation of amino acids, the building blocks of protein
    · Essential for plant cell division, vital for plant growth
    · Directly involved in photosynthesis
    · Necessary component of vitamins
    · Aids in production and use of carbohydrates
    · Affects energy reactions in the plant

PHOSPHORUS

  • Involved in photosynthesis, respiration, energy storage and transfer, cell division, and enlargement
    · Promotes early root formation and growth
    · Improves quality of fruits, vegetables, and grains
    · Vital to seed formation
    · Helps plants survive harsh winter conditions
    · Increases water-use efficiency
    · Hastens maturity

POTASSIUM
· Carbohydrate metabolism and the break down and translocation of starches
· Increases photosynthesis
· Increases water-use efficiency
· Essential to protein synthesis
· Important in fruit formation
· Activates enzymes and controls their reaction rates
· Improves quality of seeds and fruit
· Improves winter hardiness
· Increases disease resistance

SECONDARY NUTRIENTS
The secondary nutrients are calcium, magnesium, and sulphur. For most crops, these three are needed in lesser amounts that the primary nutrients. They are growing in importance in crop fertilization programs due to more stringent clean air standards and efforts to improve the environment.

CALCIUM
· Utilized for Continuous cell division and formation
· Involved in nitrogen metabolism
· Reduces plant respiration
· Aids translocation of photosynthesis from leaves to fruiting organs
· Increases fruit set
· Essential for nut development in peanuts
· Stimulates microbial activity

MAGNESIUM
· Key element of chlorophyll production
· Improves utilization and mobility of phosphorus
· Activator and component of many plant enzymes
· Directly related to grass tetany
· Increases iron utilization in plants
· Influences earliness and uniformity of maturity

SULPHUR
· Integral part of amino acids
· Helps develop enzymes and vitamins
· Promotes nodule formation on legumes
· Aids in seed production
· Necessary in chlorophyll formation (though it isn’t one of the constituents)

MICRONUTRIENTS

The micronutrients are boron, chlorine, cooper, iron, manganese, molybdenum, and zinc. These plant food elements are used in very small amounts, but they are just as important to plant development and profitable crop production as the major nutrients. Especially, they work “behind the scene” as activators of many plant functions.

BORON

  • Essential of germination of pollon grains and growth of pollen tubes
    · Essential for seed and cell wall formation
    · Promotes maturity
    · Necessary for sugar translocation
    · Affects nitrogen and carbohydrate

CHLORINE

  • Not much information about its functions
    · Interferes with P uptake
    · Enhances maturity of small grains on some soils

COPPER

  • Catalyzes several plant processes
    · Major function in photosynthesis
    · Major function in reproductive stages
    · Indirect role in chlorophyll production
    · Increases sugar content
    · Intensifies color
    · Improves flavor of fruits and vegetables

IRON

  • Promotes formation of chlorophyll
    · Acts as an oxygen carrier
    · Reactions involving cell division and growth

MAGANESE

  • Functions as a part of certain enzyme systems
    · Aids in chlorophyll synthesis
    · Increases the availability of P and CA

MOLYBDENUM

  • Required to form the enzyme “nitrate reductas” which reduces nitrates to ammonium in plant
    · Aids in the formation of legume nodules
    · Needed to convert inorganic phosphates to organic forms in the plant

ZINC

  • Aids plant growth hormones and enzyme system
    · Necessary for chlorophyll production
    · Necessary for carbohydrate formation
    · Necessary for starch formation
    · Aids in seed formation

 

In addition to the 13 nutrients listed above, plants require carbon, hydrogen, and oxygen, which are extracted from air and water to make up the bulk of plant weight.

 


Zinc deficiency

 Zinc deficiency

Zinc (Zn) is taken up by plants as the divalent Zn2+ cation. It was one of the first micronutrients recognized as essential for plants and the one most commonly limiting yields. Although Zn is required in small amounts, high yields are impossible without it.

Zinc (Zn) deficiency is growing in the Midwest, and it’s more likely to occur in corn than soybean fields. This is happening in part to earlier planting of corn in cool and moist soil. Also, more residue resulting from conservation tillage and higher grain yields places added stress on seedlings to absorb Zn from soil.

Zinc is heavily involved in enzyme systems that regulate the early growth stages, and is vital for fruit, seed and root system development; photosynthesis; formation of plant growth regulators; and crop stress protection. Further, Zn is a team player with nitrogen (N), phosphorus (P) and potassium (K) in many plant-development processes.

Soils require Zn in very small amounts compared with N or K. Only about a half-pound of Zn is needed per acre for high-yield (180 bushels per acre) corn production. Sixty-bushel wheat needs about 0.28 pound of Zn per acre. Yet, lack of Zn can limit plant growth, just like N or K, if the soil is deficient or crop uptake is restricted.

In addition to being an essential component of various enzyme systems for energy production, Zn is required in protein synthesis and growth regulation. Zinc-deficient plants also exhibit delayed maturity. Since Zn is not mobile in plant, Zn-deficiency symptoms occur mainly in new growth. This lack of mobility in plants suggests the need for a constant supply of available Zn for optimum growth.

The most visible Zn-deficiency symptoms are short internodes (rosetting) and a decrease in leaf size. Chlorotic bands along the midribs of corn, mottled leaves of dry bean and chlorosis of rice are characteristic Zn-deficiency symptoms. Loss of lower bolls of cotton and narrow, yellow leaves in the new growth of citrus also have been identified as symptoms of Zn deficiency. Delayed maturity also indicates Zn-deficient plants.

Zinc loss takes place in many ways. Deficiencies are mainly found on sandy soils low in organic matter and on organic soils. They occur more often during cold, wet spring weather and are related to reduced root growth and activity. Periods of lower microbial activity decrease Zn release from soil organic matter. Zinc uptake by plants decreases with increased soil pH. High levels of available P and iron in soils also adversely affect the uptake of Zn.

 

 

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.


Sulfur deficiency

Sulfur deficiency

 

Sulfur (S) is a part of every living cell and is a constituent of two of the 20 amino acids that form proteins. Unlike the other secondary nutrients like calcium and magnesium (which plants take up as cations), S is absorbed primarily as the S042- anion. It can also enter plant leaves from the air as dioxide (SO2) gas.

A chain is only as strong as its weakest link. Often overlooked, sulfur (S) can be that weak link in many soil fertility and plant nutrition programs. As of late, there are several reasons for the increased observance of S deficiencies and increased S needs.

Government regulations now restrict the amount of sulfur dioxide (SO2) that can be returned to the atmosphere from coal-burning furnaces. Most of the S is now removed from natural gas used in home heating and in industry. Also, catalytic converters in new automobiles remove most of the S that was previously returned to the atmosphere when S-containing gasoline was burned in automobiles. In addition, S-free compounds have replaced many of the insecticides and fungicides formerly applied to control insects and diseases in crops. As a result of these government restrictions, less S returns to the soil in rainfall.

Sulfur is supplied to plants from the soil by organic matter and minerals, but it’s often present in insufficient quantities and at inopportune times for the needs of many high-yielding crops. Organic matter ties up most S to the soil, where it remains unavailable to plants until soil bacteria convert it to sulfate (SO4-2) form. That process is known as mineralization.

Just like nitrate nitrogen (N), sulfate moves through the soil and can leach beyond the active root zone in some soils during heavy rainfall or irrigation. Sulfate may move back upward toward the soil surface as water evaporates, except in the sandier, coarse-textured soils that may be void of capillary pores. This mobility of sulfate S makes it difficult to calibrate soil tests and use them as predictive tools for S fertilization needs.

In the field, plants deficient in S show pale green coloring of the younger leaves, although the entire plant can be pale green and stunted in severe cases. Leaves tend to shrivel as the deficiency progresses.

Sulfur, like N, is a constituent of proteins, so deficiency symptoms are similar to those of N. Nitrogen-deficiency symptoms are more severe on older leaves, however, because N is a mobile plant nutrient and moves to new growth. Sulfur, on the other hand, is immobile in the plant, so new growth suffers first when S levels are not adequate to meet the plant’s need. This difference is important in distinguishing between N and S deficiencies, particularly in early stages.

 

 

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.

 


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.

 

 

 

 

 

Oxygen

Oxygen

Oxygen (O) is responsible for cellular respiration in plants. Plants acquire O by breaking down carbon dioxide (CO2) during photosynthesis and end up releasing the majority of it as an unnecessary byproduct, saving a small portion for future energy.

 

Nitrogen deficiency

Nitrogen deficiency

Nitrogen (N) is essential for plant growth and is part of every living cell. It plays many roles in plants and is necessary for chlorophyll synthesis. Plants take up most of their N as the ammonium (NH4+) or nitrate (No3-) ion. Some direct absorption of urea can occur through the leaves, and small amounts of N are obtained from materials such as water-soluble amino acids.

Nitrogen (N) surrounds all plants in our atmosphere. In fact, every acre of the Earth’s surface is covered by thousands of pounds of this essential nutrient, but because atmospheric gaseous N presents itself as almost inert nitrogen (N2) molecules, this N isn’t directly available to the plants that need it to grow, develop and reproduce.Despite its identity as one of the most abundant elements on Earth, deficient N is probably the most common nutritional problem affecting plants worldwide.

Healthy plants often contain 3 to 4 percent N in their above-ground tissues. These are much higher concentrations than those of any other nutrient except carbon, hydrogen and oxygen – nutrients not of soil fertility management concern in most situations. Nitrogen is an important component of many important structural, genetic and metabolic compounds in plant cells. It’s a major element in chlorophyll, the compound by which plants use sunlight energy to produce sugars from water and carbon dioxide, or, in other words, photosynthesis.

Nitrogen is also a major component of amino acids, the building blocks of proteins. Some proteins act as structural units in plant cells, while others act as enzymes, making possible many of the biochemical reactions on which life is based. Nitrogen appears in energy-transfer compounds, such as ATP (adenosine triphosphate), which allows cells to conserve and use the energy released in metabolism. Finally, N is a significant component of nucleic acids such as DNA, the genetic material that allows cells (and eventually whole plants) to grow and reproduce. With the exception of photosynthesis, N plays the same roles in animals, too. Without N, there would be no life as we know it.

Adequate N produces a dark green color in the leaves, caused by high concentration of chlorophyll. Nitrogen deficiency results in chlorosis (a yellowing) of the leaves because of the declining chlorophyll. This yellowing starts first on oldest leaves, then develops on younger ones as the deficiency becomes more severe. Slow growth and stunted plants are also indicators of N deficiency. Small grains and other grass-type plants tiller less when N is in short supply.

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.

Nickel deficiency

Nickel

Nickel (Ni) was added to the list of essential plant nutrients late in the 20th century. Plants absorb Ni as the divalent cation Ni2+. It is required in very small amounts, with the critical level appearing to be about 1.1 parts per million.

 

 

 

 

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.

Manganese deficiency

Manganese deficiency

Manganese (Mn) functions primarily as part of enzyme systems in plants. It activates several important metabolic reactions and plays a direct role in photosynthesis. Manganese accelerates germination and maturity while increasing the availability of phospho