Transcript mkt – kesuburan tanah unsur mikro

BAHAN KAJIAN
MK. MANAJEMEN KESUBURAN TANAH
UNSUR MIKRO
1
www.marno.lecture.ub.ac.id
UNSUR MIKRO
Unsur mikro adalah unsur esensial bagi pertumbuhan tanaman ,
tetapi dibutuhkan dalam jumlah lebih sedikit dibandingkan dengan
unsur hara makro primer N, P, dan K.
The UNSUR MIKRO are boron (B), copper (Cu), iron (Fe), manganese (Mn), Mo
(Mo), zinc (Zn), and chloride (Cl).
While chloride is a UNSUR MIKRO, deficiencies rarely occur in nature, so
discussions on supplying UNSUR MIKRO fertilizers are confined to the other six
UNSUR MIKRO.
Deficiencies of UNSUR MIKRO have been increasing in some crops. Some reasons
are higher crop yields which increase plant nutrient demands, use of high analyses
NPK fertilizers containing lower quantities of UNSUR MIKRO contaminants, and
decreased use of farmyard manure on many agricultural soils.
UNSUR MIKRO deficiencies have been verified in many soils through increased use
of soil testing and plant analyses.
UNSUR MIKRO sama pentingnya dnegan unsur makro dalam nutrisi
tanaman .
However, the amounts of UNSUR MIKRO required for optimum nutrition
are much lower.
UNSUR MIKRO deficiencies are widespread because of increased nutrient
demands from the more intensive cropping practices.
Soil tests and plant analyses are excellent diagnostic tools to monitor the
UNSUR MIKRO status of soils and crops.
Visual deficiency symptoms of these nutrients also are well recognized in most
economic crops.
UNSUR MIKRO recommendations are based on soil and plant tissue
analyses, the type of crop and expected yield, management level, and research
results.
Kandungan unsur MIKRO dalam tanah dan jaringan tanaman
B = BORON
Fungsi utama B adalah berhubungan dengan pembentukan dinding
sel, sehingga tanaman yang defisien B menjadi kerdil.
Sugar transport in plants, flower retention and pollen formation and germination
also are affected by boron.
Seed and grain production are reduced with low boron 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) and brittle, discolored leaves and loss of fruiting bodies.
Boron deficiencies are mainly found in acid, sandy soils in regions of high rainfall,
and those with low soil organic matter.
Borate ions are mobile in soil and can be leached from the root zone. Boron
deficiencies are more pronounced during drouth periods when root activity is
restricted.
Cu = Tembaga
Cu dibutuhkan dalam metabolisme karbohydrat dan nitrogen, so inadequate copper
results in stunting of plants. Copper also is required for lignin synthesis which is
needed for cell wall strength and prevention of wilting.
Deficiency symptoms of copper are dieback of stems and twigs, yellowing of leaves,
stunted growth and pale green leaves that wither easily.
Copper deficiencies are mainly reported on organic soils (peats and mucks), and on
sandy soils which are low in organic matter.
Serapan Cu menurun kalau pH tanah meningkat.
Peningkatan ketersediaan P dan Fe dalam tanah dapat menurunkan
serapan Cu oleh tanaman .
Fe = BESI
Fe terlibat dalam produksi khlorofil , dan khlorosis Fe mudah muncul
pada tanaman yang tumbuh di tanah-tanah kapur.
Iron also is a component of 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 by yellow leaves due to low levels of
chlorophyll. Leaf yellowing first appears on the younger upper leaves in interveinal
tissues. Severe iron deficiencies cause leaves to turn completely yellow or almost
white, and then brown as leaves die.
Iron deficiencies are found mainly on calcareous (high pH) soils, although some acid,
sandy soils low in organic matter also may be iron-deficient. Cool, wet weather
enhances iron deficiencies, especially on soils with marginal levels of available iron.
Poorly aerated or compacted soils also reduce iron uptake by plants. Uptake of iron
decreases with increased soil pH, and is adversely affected by high levels of available
phosphorus, manganese and zinc in soils.
Mn = Mangan
Mn dibutuhkan dalam photosynthesis, metabolisme nitrogen dan untuk
pembentukan senyawa lain yg dibutuhkan untuk metabolisme tanaman .
Interveinal chlorosis is a characteristic manganese-deficiency symptom. In very
severe manganese deficiencies, brown necrotic spots appear on leaves, resulting in
premature leaf drop. Delayed maturity is another deficiency symptom in some
species. Whitish-gray spots on leaves of some cereal crops and shortened internodes
in cotton are other manganese-deficiency symptoms.
Manganese deficiencies mainly occur on organic soils, high-pH soils, sandy soils low
in organic matter, and on over-limed soils. Soil manganese may be less available in
dry, well-aerated soils, but can become more available under wet soil conditions
when manganese is reduced to the plant-available form. Conversely, manganese
toxicity can result in some acidic, high-manganese soils.
Uptake of manganese decreases with increased soil pH and is adversely affected by
high levels of available iron in soils.
Mo = Mo
Mo terlibat dalam sistem ensim untuk fiksasi N oleh bakteri simbiotik dalam akar
legume. Nitrogen metabolism, protein synthesis and sulfur metabolism are also
affected by Mo. Mo has a significant effect on pollen formation, so fruit and grain
formation are affected in Mo-deficient plants. Because Mo requirements are so low,
most plant species do not exhibit Mo-deficiency symptoms.
These deficiency symptoms in legumes are mainly exhibited as nitrogen-deficiency
symptoms because of the primary role of Mo in nitrogen fixation. Unlike the other
UNSUR MIKRO, Mo-deficiency symptoms are not confined mainly to the youngest
leaves because Mo is mobile in plants. The characteristic Mo-deficiency symptom in
some vegetable crops is irregular leaf blade formation known as whiptail, but
interveinal mottling and marginal chlorosis of older leaves also have been observed.
Mo deficiencies are found mainly on acid, sandy soils in humid regions. Mo uptake
by plants increases with increased soil pH.
Mo deficiencies in legumes may be corrected by liming acid soils rather than by Mo
applications. However, seed treatment with Mo sources may be more economical
than liming in some areas.
Zn = SENG
Zn menjadi komponen esensial dari berbagai ensim untuk produksi energi, sintesis
protein , dan regulasi pertumbuhan tanaman . Zinc-deficient plants also exhibit
delayed maturity. Zinc is not mobile in plants so zinc-deficiency symptoms occur
mainly in new growth. Poor mobility in plants suggests the need for a constant
supply of available zinc for optimum growth. The most visible zinc-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 zinc-deficiency symptoms. Loss of lower bolls of cotton and narrow,
yellow leaves in the new growth of citrus also have been diagnosed as zinc
deficiencies. Delayed maturity also is a symptom of zinc-deficient plants.
Defisiensi Zn terutama dijumpai pada tanah-tanah berpasir yang
miskin bahan organik dan pada tanah-tanah organik .
Zinc deficiencies occur more often during cold, wet spring weather and are related
to reduced root growth and activity as well as lower microbial activity decreases zinc
release from soil organic matter.
Zinc uptake by plants decreases with increased soil pH. Uptake of zinc also is
adversely affected by high levels of available phosphorus and iron in soils.
Cl = Khlor
Cl merupakan anion mobile dalam tubuh tanaman , most of its
functions relate to salt effects (stomatal opening) and electrical charge
balance in physiological functions in plants. Chloride also indirectly
affects plant growth by stomatal regulation of water loss. Wilting and
restricted, highly branched root systems are the main chloridedeficiency symptoms, which are found mainly in cereal crops.
Most soils contain sufficient levels of chloride for adequate plant nutrition. However,
reported chloride deficiencies have been reported on sandy soils in high rainfall
areas or those derived from low-chloride parent materials.
In addition, chloride is applied to soils with KCl, the dominant
potassium fertilizer. The role of chloride in decreasing the incidence of
various diseases in small grains is perhaps more important than its
nutritional role from a practical viewpoint.
RESPON TANAMAN TERHADAP UNSUR MIKRO
SUMBER PUPUK UNSUR MIKRO
Lima macam sumber unsur mikro :
1.Produk Pupuk Organik
2. Khelat sintetik
3. Senyawa organik kompleks alamiah
4. Produk gelas frits (frits).
5. Pupuk An-organik
PUPUK MIKRO An-organik
Pupuk mikro anorganik dapat berupa: oxides and carbonates, and metallic salts
such as sulfates, chlorides, and nitrates.
The sulfates are the most common of the metallic salts and are sold in crystalline or
granular form. An ammoniated ZnSO4 solution also is used in polyphosphate starter
fertilizers.
Oxides of manganese and zinc also are commonly used, and are sold as fine powders
and in granular form. Because oxides such as ZnO and MnO are water insoluble,
their immediate effectiveness for crops is rather low in granular form.
The available divalent form of manganese in MnO will oxidize to the unavailable
tetravalent form of manganese, so there is very little residual availability of
manganese fertilizers for succeeding crops.
Agronomic effectiveness of granular MnO may be rather low. Since manganese in
MnO2 already is in the unavailable form, it should not be used as a manganese
fertilizer.
PUPUK MIKRO An-organik
Oxysulfates are oxides, usually industrial by-products, which have been
partially acidulated with sulfuric acid, and generally are sold in granular
form.
The percentage of water-soluble manganese or zinc in oxysulfates is directly
related to the degree of acidulation by sulfuric acid.
Research results have shown that about 35 to 50 percent of the total zinc in
granular zincoxysulfate should be in water-soluble form to be immediately
effective for crops.
Similar results would be expected for manganese-oxysulfate.
Pupuk mikro anorganik biasanya harganya lebih murah, tetapi
tidak selalu lebih efektif bagi pertumbuhan dan produksi
tanaman .
Khelat Sintetik
Khelat sintetik ini dibentuk dengan jalan menggabungkan agen-agen
khelat dengan logam mikro melalui ikatan koordinasi.
Stability of the metal-chelate bond affects availability to plants of the
UNSUR MIKRO metals --- copper, iron, manganese, and zinc.
An effective chelate is one in which the rate of substitution of the
chelated UNSUR MIKRO for other cations in the soil is quite low,
thus maintaining the applied UNSUR MIKRO in chelated form.
Relative effectiveness for crops per unit of UNSUR MIKRO as soilapplied chelates may be from two to five times greater than that of
inorganic sources, while chelates costs per unit of UNSUR MIKRO
may be five to 100 times higher.
SENYAWA ORGANIK KOMPLEKS ALAMIAH
These complexes are made by reacting metallic salts with some organic by-products
of the wood pulp industry or related industries.
Beberapa tipe senyawa organik kompleks ini adalah :
lignosulfonates, polyflavonoids dan phenols.
The types of chemical bonding of the metals to the organic components are not well
understood. Some bonds may be coordinate as in the chelates, but other types of
chemical bonds also may be present.
While natural organic complexes are less costly per unit of UNSUR MIKRO, they
usually are less effective than synthetic chelates. They also are more readily
decomposed by microorganisms in soil.
These sources are more suitable for foliar sprays and mixing with fluid fertilizers.
Frits
Fritted glassy products (frits) in which solubility is controlled by
particle size and changes in matrix composition.
Kandungan UNSUR MIKRO beragam 2 - 25 %, and more than
one UNSUR MIKRO may be included in a fritted product.
Fritted UNSUR MIKRO generally are used only on sandy soils in
regions of high rainfall were leaching occurs. This class of
materials is more appropriate for maintenance programs than
for correcting severe UNSUR MIKRO deficiencies.
Therefore, frits only have a small share of the UNSUR MIKRO
market.
Aplikasi dengan pupuk campuran
The most common method of UNSUR MIKRO application for crops is soil
application.
Recommended application rates usually are less than 10 lb/acre (on an elemental
basis), so uniform application of UNSUR MIKRO sources separately in the field
is difficult. Therefore, both granular and fluid NPK fertilizers are commonly
used as carriers of UNSUR MIKRO. Including UNSUR MIKRO with mixed
fertilizers is a convenient method of application and allows more uniform
distribution with conventional application equipment. Costs also are reduced by
eliminating a separate application.
Four methods of applying UNSUR MIKRO with mixed fertilizers are:
1. Pencampuran selama pembuatan pupuk
2. Blending dengan pupuk granuler
3. Penyelimutan pada pupuk granuler
4. Pencampuran dengan uppuk cairan
Pencampuran dengan Pupuk Granuler
Incorporation during manufacture results in uniform distribution of UNSUR
MIKRO throughout granular NPK fertilizers.
Because the UNSUR MIKRO source is in contact with the mixed fertilizer
components under conditions of high temperature and moisture, the rate of
chemical reactions which may reduce the plant availability of some UNSUR
MIKRO is increased.
For example, acid decomposition of ZnEDTA or any synthetic chelate may occur
if they are mixed with phosphoric acid before ammoniation during manufacture,
which results in reduced plant availability of the UNSUR MIKRO.
Immediate plant availability of applied zinc in granular ammoniated phosphates
also decreases with the level of water-soluble zinc in these products.
Blending dengan Pupuk Granuler
Bulk blending of UNSUR MIKRO with granular NPK fertilizers is a common
practice in the world.
The main advantage is that fertilizer grades can be produced which will provide the
recommended UNSUR MIKRO rates for a given field at the usual fertilizer
application rates. The main disadvantage is that segregation of nutrients can occur
during the blending operation and with subsequent handling. Segregation results in
non-uniform application, which is critical with UNSUR MIKRO since their
application rates are quite low.
Segregation can be minimized by properly matching particle sizes of UNSUR
MIKRO sources with those of the NPK components of the blend. Mechanical devices
to minimize coning and segregation of the materials during handling and storage are
available. Blending of various sized fertilizer particles results in nonuniform
application because of segregation in the applicator during transport and spreading
operations.
Penyelimutan Pupuk Granuler
Coating powdered UNSUR MIKRO onto granular NPK fertilizers decreases the
possibility of segregation, which is the main disadvantage of bulk blending
UNSUR MIKRO with mixed fertilizers.
Fertilizer solutions are preferred as binding agents because the fertilizer grade is
not decreased so much as with use of water, oils and waxes. Some binding
materials are unsatisfactory because they do not maintain the UNSUR MIKRO
coatings during bagging, storage, and handling. This results in segregation of the
UNSUR MIKRO sources from the granular NPK components.
Agronomic effectiveness of UNSUR MIKRO coated onto soluble granular NPK
fertilizers should be similar to that with incorporation during manufacture. This
method of UNSUR MIKRO application is not commonly used because of the
extra costs associated with coating.
PUPUK CAIR
Mixing UNSUR MIKRO with fluid fertilizers has become a popular method of
application, especially Clear liquids are commonly used as starter fertilizers for
row crops and some UNSUR MIKRO, especially zinc sources, are easily applied
with these fluids.
Solubility of some UNSUR MIKRO sources is higher in polyphosphate fertilizers
such as 10-34-0 than in orthophosphate clear liquids.
UNSUR MIKRO also may be applied with nitrogen solutions such as UAN, but
solubility of many sources is rather low. Compatibility tests should be made before
tank mixing operations of UNSUR MIKRO with fluid fertilizers are attempted;
otherwise, problems could occur when incompatible sources are mixed.
Suspension fertilizers also are used as UNSUR MIKRO carriers. Oxides also can
be applied with suspensions since complete solution is not required.
Penyemprotan Daun = Foliar Sprays
Foliar sprays are widely used to apply UNSUR MIKRO, especially iron and
manganese, for many crops. Soluble inorganic salts generally are as effective as
synthetic chelates in foliar sprays, so the inorganic salts usually are chosen because
of lower costs.
Advantages of foliar sprays are: (1) application rates are much lower than for soil
application; (2) a uniform application is easily obtained; and (3) response to the
applied nutrient is almost immediate so deficiencies can be corrected during the
growing season. Low residue foliar sprays of manganese and zinc have been used to
correct deficiencies of citrus and other fruit crops, but sprays which will discolor the
fruit should be avoided.
Disadvantages of foliar sprays are: (1) leaf burn may result if salt concentrations of
the spray are too high; (2) nutrient demand often is high when the plants are small
and leaf surface is insufficient for foliar absorption; (3) maximum yields may not be
possible if spraying is delayed until deficiency symptoms appear; and (4) there is
little residual effect from foliar sprays.
Application costs will be higher if more than one spray is needed, unless they can be
combined with pesticide spray applications.
DOSIS UNSUR MIKRO
Boron
Rekomendasi dosis aplikasi Boron agak rendah (0.5 to 2 lb/acre), but
should be carefully followed because the range between boron
deficiency and toxicity in most plants is narrow.
Uniform application of boron in the field is very important for the
above reason. Boronated NPK fertilizers (those containing boron
sources incorporated at the factory) will insure a more uniform
application than most bulk blended fertilizers.
Aplikasi daun (Foliar sprays) also insure a rather uniform application,
but costs generally are higher.
Pengaruh pH tanah terhadap ketersediaan Boron dan Hasil Kapas
Hasil penelitian di Arkansas, hasil kapas meningkat sebesar 490 dan
584 lb/acre pada pemupukan B sebesar 0.3 dan 0.5 lb/acre.
Without applied boron, cotton yields decreased with increasing soil
pH. Yields were increased at all soil pH levels when boron was applied
at a rate of 0.5 lb/acre.
Soil tests should be included in boron fertilization programs, first to
assess the level of available boron and later to determine possible
residual effects (buildup).
The most common soil test for boron is the hot-water-soluble test. This
test is more difficult to conduct than most other UNSUR MIKRO soil
tests, but most boron response data have been correlated with it.
DOSIS UNSUR MIKRO
Cu = Copper
Rekomendasi dosis aplikasi Cu berkisar 3 - 10 lb/acre as CuSO4 or
finely ground CuO.
Residual effects of applied copper are very marked, with responses being noted up to
eight years after application.
Because of these residual effects, soil tests are essential to monitor possible copper
accumulations to toxic levels in soils where copper fertilizers are being applied.
Plant analyses also can be used to monitor copper levels in plant tissues.
Copper applications should be decreased or discontinued when available levels
increase beyond the deficiency range.
DOSIS UNSUR MIKRO
Fe = Iron
Aplikasi tanah pupuk mikro Fe biasanya tidak efektif bagi
tanaman , so foliar sprays are the recommended application
method.
Spray applications of a 3 to 4% FeSO4 solution at 20 to 40 gallons/acre are
used to correct iron deficiencies. The application rate should be high enough to
wet the foliage. More than one foliar application may be required for
correction of iron chlorosis.
Inclusion of a sticker-spreader agent in the spray is suggested to improve
adherence of the spray to the plant foliage for increased iron absorption by the
plant.
DOSIS UNSUR MIKRO
Manganese
Rekomendasi dosis aplikasi Mn berkisar 2 - 20 lb/acre Mn, biasanya
dalam bentuk MnSO4.
Application rates of MnO would be similar if applied as a fine powder or in NPK
fertilizers.
Band application of manganese sources with acid-forming fertilizers results in a
more efficient use of applied manganese because the rate of oxidation of applied
manganese to the unavailable tetravalent form (as in MnO2) is decreased. There are
no residual effects of applied manganese for the same reason, so annual applications
are needed.
Foliar spray applications of MnSO4 also are used and require lower rates than soil
applications.
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Respon Kedelai terhadap Pupuk Mn
Respons Kapas terhadap Pupuk Mn
DOSIS UNSUR MIKRO
Mo
Rekomendasi dosis aplikasi Mo, are much lower than those for the
other UNSUR MIKRO, and uniform application is very important.
Broadcast application of molybdenized phosphate fertilizers prior
to planting or to pastures has been used to correct Mo deficiencies.
Soluble Mo sources also can be sprayed on the soil surface before
tillage to obtain a uniform application.
Response Kedelai terhadap Mo
Aplikasi Pupuk Mo
Perlakuan benih merupakan metode aplikasi pupuk mikro Mo yang
paling lazim dilakukan.
Mo sources are coated onto the seed with a sticking agent and/or
conditioner. This method insures a uniform application and sufficient
amounts of Mo can be seed coated to provide
sufficient Mo .
Data in the following table show the effectiveness for soybean of seedcoated Mo at a rate of one ounce of Mo/acre.
Soybean yields without applied Mo increased with increases in soil
pH, but not as high as those with seedapplied Mo at each soil pH
level
DOSIS UNSUR MIKRO
Zinc
Rekomendasi dosis aplikasi Zn berkisar 1 - 10 lb/acre. Band or broadcast
applications are used, but foliar applications also are effective.
Band applications of zinc sources with starter fertilizers is a common practice for
row crops.
Foliar sprays of a 0.5% ZnSO4 solution applied at a rate of 20 to 30 gallons/acre
also will supply sufficient zinc, but several applications may be necessary.
Residual effects of applied zinc are substantial, with responses found at least 5
years after application. Because of these residual effects, soil test levels of
available zinc generally increase after several applications. Many states have
reduced their recommended zinc application rates because of these residual
effects.
Crop response to several zinc sources each banded with a 10-34-0 starter
fertilizer at zinc rates up to 3 lb/acre for corn in Nebraska is shown below.
Results show that ZnEDTA was much more effective at the lower zinc rates, but
all zinc sources were about equally effective at the highest zinc rate.
Response Jagung terhadap Pupuk Zn
Kapan UNSUR MIKRO dibutuhkan Lahan Pertanian ?
Boron
Uji tanah untuk Boron (B) masih jarang dilakukan .
A general boron recommendation is made for cotton, broccoli, cauliflower and
cabbage. Two pounds of boron per acre are recommended for alfalfa, broccoli,
cauliflower and cabbage.
One-half pound of boron per acre is recommended for cotton when the pH is
above 6.0 or anywhere lime is used.
A pound of boron per acre is recommended for burley or dark tobacco
anywhere deficiency symptoms have been noted previously or where plant
analysis results show a need for boron.
Kapan UNSUR MIKRO dibutuhkan Lahan Pertanian ?
Iron
Uji tanah Fe banyak dilakukan dalam usahatani tanaman hias :
azaleas, hydrangeas, etc.
Iron sulfate is a commonly used and locally available source for iron. Chelated iron
sources are often more appropriate for established plantings when soil pH is very
much above the desired range. Such use is not based upon soil test results but upon
plant appearance (unthrifty and usually chlorotic [yellowing] condition).
If soil is tested prior to plant establishment, then a more desirable approach is to
avoid an iron deficiency by lowering the soil pH using elemental sulfur or other
acidifying amendments well ahead of planting.
The soil test lab report gives specific instructions for amount of elemental sulfur (the
most economical soil-acidifying material) to use.
Lowering of soil pH or attempted correction of iron deficiency after establishment of
shrubs or small fruits is a salvage operation that usually does not achieve the desired
result.
Kapan UNSUR MIKRO dibutuhkan Lahan Pertanian ?
Manganese
Manganese (Mn) is recommended only for soybeans when soil pH
is above 7.0 and soil test manganese is below 16 pounds per acre.
The recommendation is to apply 20 pounds of manganese per
acre broadcast just prior to planting.
NOTE:
Manganese should not be confused with magnesium nor should it
be requested when manganese toxicity (low soil pH) is the
problem.
Kapan UNSUR MIKRO dibutuhkan Lahan Pertanian ?
Mo
Aplikasi pupuk Mo melalui Perlakuan-benih lazim digunakan
dlaam usahatani kedelai.
Treat seed with 0.2 ounce actual Mo per bushel when the soil pH
is 6.5 or below.
This can be accomplished by applying either 0.5 ounce of sodium
molybdate per bushel of seed or following the product label for
specific liquid hopper-box-applied sources containing fungicides.
Research has shown very favorable results to seed application of
Mo down to a soil pH of about 5.8.
Kapan UNSUR MIKRO dibutuhkan Lahan Pertanian ?
Zinc
A general zinc (Zn) recommendation is made for corn and snap beans on soils
from those counties where zinc deficiencies commonly occur . However, when
zinc is tested on a soil sample from any county for corn or snap beans, the zinc
recommendation is based on the result of the soil test as follows: If the Zn
results are two pounds per acre or less, five pounds of elemental zinc per acre
will be recommended for corn or two pounds per acre for snap beans.
Also, a general zinc recommendation of two pounds of zinc sulfate per 1000
square feet is made for pecan trees. Unless deficiency symptoms persist, this
should be considered as a one-time application.
When a zinc soil test is requested for crops other than corn or snap beans, the
results are always reported as sufficient.
Zinc sulfate is the commonly used and locally available source for Zn.
SIKLUS UNSUR MIKRO
Metals exist in one of four forms in the soil: mineral, organic, sorbed (bound
to soil), or dissolved. The majority of metals in soil are bound in minerals and
organic matter , and are unavailable to plants. Sorbed metals represent the third
largest pool, and are generally very tightly bound to soil surfaces. Although
mineral, organic, and sorbed metals are not immediately plant available, they can
slowly release metals into solution.
Dissolved metal concentrations are usually very low, especially at soil pH levels
typical for Montana and Wyoming. The concentration of plant available metals
can be estimated with an organic extractant such as DTPA. The total
concentrations of metals in soil (determined by extracting with strong acids) are
generally orders of magnitude higher than plant available metals (Table 1). Most
notably, the available Fe concentration represents less than 0.1% of the average
total Fe concentration in soils. The processes that determine the amount of metals
available in solution are: plant uptake, sorption/desorption,
precipitation/dissolution, mineralization/ immobilization, erosion, and crop
removal.
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SIKLUS UNSUR MIKRO LOGAM
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FAKTOR KETERSEDIAAN UNSUR MIKRO
Ketersediaan unsur mikro sangat dipengaruhi oleh pH
tanah.
Mo exhibits the opposite effect, with increased availability
at higher pH.
Cl availability is independent of pH.
Factors other than pH that affect UNSUR MIKRO
availability are discussed below.
Ketersediaan unsur mikro dalam tanah sangat dipengaruhi oleh pH
tanah
FAKTOR KETERSEDIAAN
COPPER
High C:N organic material or residues can
cause Cu deficiency due to uptake by
microorganisms, sorption, and inhibited root
development, likely caused by low available N
concentrations.
Sandy soils generally have a higher likelihood
of Cu deficiency than finer-textured soils.
FAKTOR KETERSEDIAAN
IRON
Most Fe deficiencies occur on calcareous, high pH soils.
In addition, periods of saturation in poorly aerated soils
can enhance Fe deficiency, possibly due to reduced
nutrient absorption under these conditions.
Fe deficiency is also more common on soils low in OM,
especially where land leveling has removed the upper
organic rich soils and exposed calcareous subsoil.
Chelators in OM will increase Fe availability.
Pengaruh pH dan Eh tanah terhadap ketersediaan Fe dalam tanah
Penyerapan Fe oleh akar tanaman
FAKTOR KETERSEDIAAN
MANGANESE
Penambahan bahan organik dapat meningkatkan Mn tersedia,
meskipun tanah-tanah yang secara alami kaya BOT kadangkala
menunjukkan defisiensi Mn .
This apparent discrepancy is due to the relative availability of Mn in
recently added organic amendments compared to older materials
where decomposition has slowed considerably.
Dry weather increases Mn deficiency likely due to precipitation of
unavailable Mn oxides. Saturated conditions cause some Mn
minerals to dissolve and become available to plants.
FAKTOR KETERSEDIAAN
ZINC
Bahan organik dapat meningkatkan ketersediaan Zn karena
mekanisme khlesai dan mineralisasi, but at very high levels, can
decrease Zn availability due to sorption and precipitation of organicZn solids.
For example, Zn deficiency can occur in peat soils due to these
second two reactions.
High concentrations of available soil P have been found to cause Zn
deficiencies in both sugar beets and dry beans (Halvorson and
Bergman, 1983).
FAKTOR KETERSEDIAAN
BORON
Aplikasi bahan organik dapat meningkatkan serapan B
likely due to both chelation and mineralization.
Fine soils retain and release B better than coarse soils.
Soils high in K may increase B deficiencies, although the
reason for this effect is unknown (Havlin et al., 1999).
Any drought conditions can increase B deficiencies, likely
due to slower diffusion.
FAKTOR KETERSEDIAAN
CHLORIDE
Cl deficiencies can be attributed to indigenous soils being very low in
Cl levels, little Cl being deposited from the atmosphere, and until
recently, limited application of potash (KCl).
Cl mudah tercuci dari dalam tanah , dan defisiensi Cl dapat terjadi
di daerah-daerah dengan curah hujan tinggi .
Wheat is one of the crops that have had confirmed Cl deficiencies.
FAKTOR KETERSEDIAAN
Mo
Tanah-tanah yang kaya oksidaoksida Fe dan/atau Al
akan mengikat kuat Mo , sehingga mereduksi
ketersediaan Mo bagi tanaman .
Higher levels of phosphate increase Mo availability
because P and Mo are so similar that P will compete
for the same sorption sites as Mo, resulting in Mo
desorption.
UJI UNTUK UNSUR MIKRO
How do you know if your field or crop is deficient in one of the
UNSUR MIKRO, and therefore, if UNSUR MIKRO fertilization
would be expected to result in a yield response?
Gejala defisiensi sering digunakan untuk diagnosis defisiensi unsur
mikro. Akan tetapi, seringkali tanaman mengalami ‘hidden
hunger’, mereka sebenarnya defisien hara mikro, tetapi belum
menunjukkan gejala defisiensi yang spesifik .
In addition, many of the UNSUR MIKRO deficiencies look similar,
making testing of soil or plant tissue essential for determining if a
response to a UNSUR MIKRO fertilizer is likely or not.
Uji Tanah untuk UNSUR MIKRO
Pengambilan Contoh Tanah (Soil sampling)
Once the soils are collected, they are delivered to a laboratory for testing. UNSUR
MIKRO availability in soils is tested with a variety of methods, although some
tests have become more standard than others.
Metals are typically measured with diethylenetr iaminepetaacetic acid (DTPA), a
chelator designed to extract the most readily available metals. DTPA is buffered
with triethanolamine (TEA) to maintain a pH near 8, because pH can greatly
affect metal solubility as pointed out earlier.
Chloride is measured in a water extract, and a hot water extraction is the most
typical for B.
Soil test results should be compared with UNSUR MIKRO fertilizer guidelines for
your state. Decisions on UNSUR MIKRO fertilization should depend on
knowledge of growth responses to UNSUR MIKRO fertilization in the local area.
In addition, as pointed out earlier, fertilizer solubilities and forms may greatly
affect the amount of fertilizer needed to produce a growth response.
Rekomendasi pemupukan UNSUR MIKRO berdasarkan Analisis Tanah
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Uji Jaringan Tanaman untuk UNSUR MIKRO
An alternative to soil testing is to sample plant tissue for UNSUR
MIKRO, and compare the tissue concentrations to a sufficiency
range for a particular crop.
A sufficiency range for small grains of 15-70 ppm Zn contained in
the four uppermost leaves from the top of the plant.
There is a few published fertilizer recommendations for a specific
UNSUR MIKRO tissue test.
Due to the variability within a plant, and the variability within a
growing season , tissue testing is less accepted than soil sampling for
determining fertilizer requirements, yet can represent a reasonable
tool to identify deficiencies.
RESPON PERTUMBUHAN thd UNSUR MIKRO
Boron
Deficiencies of B in alfalfa have been identified in Western Montana.
Conversely, studies conducted in the Western Triangle (Ledger, Montana) on
alfalfa found no significant growth responses to B fertilization even on a soil with a
soil test B of only 0.41 ppm (Jackson and Miller, 1998).
A study of 33 sites in the three prairie provinces of Canada found no correlation
between the relative yield of canola seed and hot water-extractable B (Goh and
Karamonos, 2002).
In addition, foliar, broadcast, and incorporation of B at four of these sites
produced no significant yield increases, and a significant yield decrease at one of
these sites that had only 0.5 ppm water-soluble B.
The conclusion of the study was that responses to B fertilizer are likely rare on
Canadian prairie soils.
RESPON PERTUMBUHAN thd UNSUR MIKRO
Chloride
A soil near Poplar, Montana that had an average of 0.64 ppm Cl in the upper 3 feet
was fertilized with 0 and 40 lb/acre Cl (as KCl) and planted with durum wheat.
The Cl fertilizer decreased spot severity from 87% to 6% in the flag leaf, and
increased yield by 22% (Table 3). Previous work on winter wheat found that grain
yield increased 16% when 20 lb Cl/acre was applied to a soil containing
approximately 1.5 ppm Cl in the upper 2 feet (Engel et al., 1998).
In both studies, K 2SO4 was applied as the check treatment to make certain that K
was not causing the yield increase.
Results from studies on both winter and spring wheat suggest a critical plant tissue
Cl concentration between 1,000 and 4,000 ppm (Engel et al., 1998). It was
determined that soil Cl plus fertilizer Cl should be between 8.5 and 36 lb/ac to
reach these minimum and maximum critical concentrations.
Chloride has also been found to prevent plant diseases such as root rot and spot
blotch in small grains in North Dakota (Havlin et al., 1999).
RESPON PERTUMBUHAN thd UNSUR MIKRO
Copper
A study conducted at the Western Tiangle Agricultrual
Research Center in Conrad, Montana, on a soil with 1.2 ppm
extractable Cu, found no yield increases in 9 of 10 spring
wheat and durum varieties (Jackson and Christiaens, 1995).
Yield responses to Cu are not expected in most Montana soils
based on a study that found that 100% of 301 producer soils
in Montana tested adequate (>0.2 ppm) in DTPA Cu (Haby
and Sims, 1979).
Studies in Alberta have found Cu fertilization has resulted in wheat
yield increases of up to three-fold in soils having extractable Cu
concentrations <0.4 ppm (Goh and Karamanos, 2001).
RESPON PERTUMBUHAN thd UNSUR MIKRO
BESI
Iron deficiency is observed in the Great Plains, especially in corn and legumes
grown on high pH, calcareous soils. Deficiencies are indicated by ‘interveinal
chlorosis’, which means that the veins remain green, yet the leaves between the
veins are yellow.
A study on a pH 8.6 soil with 2.9 ppm DTPA Fe in Nebraska assessed the effect of
Fe fertilizers on sweet corn yields for both chlorosis-tolerant and non-tolerant
hybrids.
The study found that the average yield of tolerant hybrids was approximately
sixfold higher than the yield of non-tolerant hybrids from 1997-1999 .
In addition, Fe fertilizer placed in seed rows (2 inches to the side and 2 inches
below the seed) was able to overcome most of the difference between hybrids,
although yield decreased at the highest Fe treatment (30 lb Fe/ac), likely due to a
salt effect.
Similar yields were obtained using either a liquid Fe suspension or dry granules.
RESPON PERTUMBUHAN thd UNSUR MIKRO
ZINC
Dry beans grown in the Lower Yellowstone Valley of Montana have been
noted to have Zn deficiencies, especially when grown in soil with high available P
concentrations.
Foliar and soil applications of Zn were applied to an irrigated silty clay in the
valley that had greater than 60 ppm soil test P and less than 1.2 ppm DTPA Zn.
Average grain yield over a three year period was increased by approximately 300
lb/ac with a foliar application of 1 lb Zn/ac as ZnSO4, and by up to 700 lb/ac when
soil was fertilized with ZnEDTA (a chelated form of Zn) at 5 lb Zn/ac .
The yield response was highly probable on soils with > 25 ppm soil test P and < 1.5
ppm DTPA Zn. To overcome Zn deficiencies, they recommended using ZnSO4
(due to cost) either as a 0.5% solution at 20 to 30 gal/ac for a foliar application or
10 lb Zn/ac broadcast or incorporated before seeding. Based on the low mobility of
Zn, banding and direct seed applications should be effective application methods.
RESPON PERTUMBUHAN thd UNSUR MIKRO
ZINC
A 5 lb Zn/ac starter fertilizer, placed 2 inches to the side and 2 inches below the
seed, increased navy bean yield by approximately 12% near Powell, Wyoming
(Blaylock, 1996). In addition, the damage percentages of harvested bean seed were
14.7% for the check treatment and 8.8% for the 5 lb Zn/ac treatment.
Fertilizing a loamy sand in Colorado that had low available Zn (0.48 ppm) with 3
ppm Zn increased corn yield by approximately 4 – 30% depending on the form of
Zn fertilizer (Westfall et al., 2001).
The fertilizers with higher concentrations of water-soluble Zn (ZnSO4, ZnEDTA,
and a combined ZnSO4-paper waste) resulted in significantly higher yields than
the lowest water-soluble Zn fertilizer (Zn sucrate). Therefore, if fertilizing with Zn,
make certain to compare price per percent water-soluble Zn.
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The effect of Fe fertilization on corn yield in a high pH, low Fe soil
for both chlorosis-tolerant and non-tolerant hybrids (modified from
Stevens et al., 2001).
Increase in yield due to Zn fertilization on a low Zn (<1.2 ppm), high
P (>60 ppm) soil in Montana (data from Halvorson and Bergman,
1983).
ZnMNS is a zinc, manganese, nitrogen, and sulfur mix.
PUPUK MIKRO
PUPUK MIKRO are generally supplied as either liquid foliar
applications or dry product for application to the soil.
Foliar applications are often more effective per pound of UNSUR
MIKRO because a higher percentage of the applied nutrient is
generally absorbed by the plant. Due to the cost of mixing and
transporting liquids, however, foliar applications are more expensive
per pound of UNSUR MIKRO.
Therefore, the decision regarding whether to purchase foliar or dry
product formulations will generally be driven by ease of application
and economics.
PUPUK MIKRO yang ada
Chelated forms of metal UNSUR MIKRO, such as ZnEDTA, are generally much
more expensive than non-chelated forms, but are also much more effective per lb of
Zn .
In choosing a fertilizer, target those with medium-high solubilities, and compare cost
per percentage of UNSUR MIKRO.
Perhitungan dosis PUPUK MIKRO untuk menentukan jumlah UNSUR MIKRO
fertilizer to apply is very similar to determining the amount of N fertilizer to apply.
First, use historical data, your experience, or soil test data combined with researchbased fertilizer guidelines to determine the pounds of UNSUR MIKRO to add per
acre.
In irrigated areas of Montana and Wyoming, irrigation water should be tested and
the results considered before UNSUR MIKRO fertilizers are prescribed.
This is particularly important for irrigated fields using re-used return flows.
Second, choose a fertilizer based on availability and the criteria outlined above.
Third, calculate the fertilizer requirement based on the percentage of UNSUR
MIKRO .
Contoh perhitungan
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Pupuk Sumber UNSUR MIKRO
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UNSUR MIKRO are no less essential to plant growth than the macronutrients;
they are simply needed in smaller amounts. The metal UNSUR MIKRO are held
strongly by the soil, especially at pH levels above 7. The anion UNSUR MIKRO
are held less strongly; with the exception of Mo.
In areas where UNSUR MIKRO deficiencies occur, the ability to identify these
deficiencies either visually, with soil testing, or with plant tissue testing is necessary
to determine if UNSUR MIKRO fertilizers are needed.
The most common UNSUR MIKRO deficiencies are believed to be boron, chloride,
iron and zinc.
UNSUR MIKRO deficiencies can usually be overcome with fertilizers, although
additions of organic matter, such as manure, will often increase UNSUR MIKRO
availability.
Due to the poor mobility of most UNSUR MIKRO, placement near the seed, foliar
applications, and using ‘chelated’ UNSUR MIKRO have proven most successful at
producing growth responses.
REKOMENDASI PUPUK MIKRO untuk SAYURAN
The elements zinc, manganese, copper, boron, iron, and Mo are
required by vegetables in very small amounts, and are accordingly
termed ‘UNSUR MIKRO’.
A UNSUR MIKRO deficiency can be just as limiting and reduce
yields just as much as a deficiency of any major nutrients. In
addition, when present in the soil in excessive amounts, some
UNSUR MIKRO (most commonly boron and manganese, but
sometimes zinc and copper) can have adverse effects on
vegetables.
Subsequently, while a deficiency of a UNSUR MIKRO can reduce
yields, overuse or incorrect UNSUR MIKRO application can be
harmful to vegetable growth as well.
REKOMENDASI PUPUK MIKRO untuk SAYURAN
Respon Tanaman
Vegetables show a wide range of response to UNSUR MIKRO, and a UNSUR
MIKRO deficiency is highly crop-specific.
If the soil is low or deficient in a certain UNSUR MIKRO, response to application
of that UNSUR MIKRO would likely occur if the crop has a high requirement for
that UNSUR MIKRO; response would probably occur if the crop has a medium
requirement; and response would likely not occur if the crop has a low
requirement.
For example, boron is the most widely deficient UNSUR MIKRO in vegetables.
Under conditions of low boron supply in the soil, crops like beets, broccoli, and
cauliflower, which have a high requirement for boron, would likely show a growth
response to boron fertilization, while crops such as beans, cucumbers, and peas,
which have relatively low requirements for boron would be unresponsive to added
boron fertilizer.
REKOMENDASI PUPUK MIKRO untuk SAYURAN
Deficiency Situations
Pada umumnya defisiensi UNSUR MIKRO dipengaruhi oleh lima kondisi :
(1) strongly weathered soils; 2) coarse textured soils (i.e. sands); 3) high soil pH; 4)
highly organic soils (i.e. peats and mucks); 5) soils inherently low in organic matter
or are low in organic matter because of processes that have removed the topsoil.
UNSUR MIKRO fertilization should be used when verified deficiencies exists, or
when certain crops have a high nutrient requirement, such as boron for beets.
Because most UNSUR MIKRO soil tests have relatively low reliability (except soil
B), UNSUR MIKRO plant analysis will probably provide a better estimator of
UNSUR MIKRO need than soil tests.
REKOMENDASI PUPUK MIKRO untuk SAYURAN
METODE APLIKASI
Petani mempunyai beragam pilihan untuk melakukan pemupukan unsur mikro,
termasuk metode aplikasi (broadcast, band, foliar) dan formulasi pupuk mikro
(inorganic, chelate).
Band application is generally more effective than broadcast application in
calcareous soils by reducing fertilizer contact with soil particles.
In general, foliar application will correct UNSUR MIKRO deficiency problems
most rapidly. However, this effect may be short-lived, particularly for severe
deficiencies, and additional applications may be necessary. To avoid plant injury
with foliar application, care must be taken not to exceed recommendation rates.
This precaution is especially true with chelates, where relatively low levels of
UNSUR MIKRO are required when applied directly to foliage.
Kebutuhan Zn dari Tanaman
Kebutuhan Mn dari Tanaman
Kebutuhan B dari Tanaman
Kebutuhan Fe dari Tanaman
Kebutuhan Cu dari Tanaman
Kebutuhan Mo dari Tanaman
KHELATE UNSUR MIKRO
UNSUR MIKRO diaplikasikan ke tanah hanya apabila terjadi gejala defisiensi .
Uji tanah atau jaringan daun akan menentukan derajat defisiensi unsur.
Dosis aplikasi pupuk mikro ke tanah adalah maksimum.
Chelating agents such as EDTA (ethylene diamine tetraacetate) are large organic
structures that form a complex with UNSUR MIKRO.
This complex forms a larger chelated ion which reduces the ability of the UNSUR
MIKRO to react with the soil, making the UNSUR MIKRO more available for
plant uptake.
The chelating agent keeps the UNSUR MIKRO in solution even when the soil pH
is higher than desired for a specific crop.
Plants are able to absorb chelates very easily and there is less chance of burning
roots than if sulphates are used.
Khelate unsur mikro
EDTA
Ethylene diamine tetra-acetate or EDTA is the most economical of the commonly
used chelating agents. It is used to chelate Fe, Mn, Cu, Zn and Mg and is very
effective in the acid-neutral pH range 5 - 7.0.
DTPA
Diethylene triamine pentaacetate or DTPA is a special chelating agent, generally
used only with iron and effective over a larger pH range, particularly somewhat
alkaline conditions 5 - 7.5. This is important in hydroponic growing systems.
EDDHA
Ethylene diamine dihydroxyphenyl acetate or EDDHA is particularly good at
chelating Iron over a very wide pH range, going as high as 8.5. Cut flower growers
sometimes apply a portion of their iron requirement in the form of EDDHA.
Copper Chelate 14% Copper (Cu)
63.4% EDTA Chelating Agent
Ketersediaan Cu sangat dipengaruhi oleh pH tanah ,
jumlah bahan organik dan adanya kation logam
lainnya, seperti Fe dan Mg .
Copper Chelate can be applied as a soil or foliar
application to correct copper deficiency in ornamentals,
turf, field crops and fruit trees growing in alkaline or
acid soils.
Iron Chelate 7% Iron (Fe)
48.6% DTPA Chelating Agent
Khelat besi ini menjadi sumber Fe bagi tanaman
hortikultura dan tanaman pertanian, terutama pada
kondisi tanah agak alkalin .
It can be used for correcting a deficiency or as a
constant feed, in hydroponics, substrate culture, soil or
soilless media.
Applikasinya dapat melalui daun atau media tumbuh.
Iron Chelate 13.2% Iron (Fe)
68% EDTA Chelating Agent
Defisiensi Fe menjadi masalah serius pada kondisi tanah-tanah dengan pH tinggi .
Iron Chelate can be used to correct iron deficiency in ornamentals, turf and fruit
trees. This product contains 13.2% chelated iron and can be applied as a foliar spray
or soil drench to crops such as chrysanthemums, gardenia, hydrangea, rose, azalea,
holly, rhododendron, turf and fruit trees.
Woody Plants:
0.5 kg/100 m2 as a drench
1 kg/1000 L as a spray
(1 lb./1000 ft2 or 1 lb./100 gal. water)
Herbaceous Plants:
0.5 kg/100 m2 as a drench
250 to 500 g/1000 L water as a spray
(1 lb./1000 ft2 or 1/4-1/2 lb./100 gal. water)
Manganese Chelate 13% Manganese (Mn)
68.1% EDTA Chelating Agent
Manganese deficiency results in reduced photosynthetic
activity.
Kondisi tanah dnegan pH tinggi, miskin BOT atau tanah-tanah
berpasir akan mereduksi ketersediaan Mn .
Manganese Chelate can be used to correct
deficiencies in ornamentals, turf, field crops and fruit trees.
Zinc Chelate 14% Zinc (Zn)
61.7% EDTA Chelating Agent
Zn mempunyai peranan sangat penting dalam
pemanfaatan unsur hara lainnya.
Defisienai umumnya terjadi pada tanah-tanah berpasir ,
tanah-tanah miskin bahan organik dan tanah-tanah
yang telah dipupuk fosfat dosis tinggi.
Depending on the crop, zinc deficiencies can be
corrected by soil or foliar applications.
UNSUR MIKRO
dalam
PRODUKSI KENTANG
UNSUR MIKRO yang dibutuhkan tanaman kentanh : Boron (B), Chlorine (Cl),
Cobalt (Co), Copper (Cu), Iron (Fe), Manganese (Mn), Mo (Mo), Selenium (Se),
Sodium (Na), dan Seng (Zn).
The availability of these nutrients in the soil depends on the soil and the
environment. For example, Zn is a relatively immobile nutrient that is
concentrated in the soil organic matter near the soil surface. Cool, wet weather
reduces the availability of Zn, possibly resulting in a deficiency.
Ketersediaan UNSUR MIKRO umumnya menurun kalau pH tanah meningkat .
Availability of B, Cu and Zn declines rapidly as soil pH rises above 7 . Therefore,
deficiencies can occur in soils with high pH.
Also, sandy soils are more likely to show UNSUR MIKRO deficiencies than clay
soils.
Gejala Defisiensi Boron, zinc dan copper Tanaman Kentang
Pengelolaan kesuburan tanah untuk tanaman kentang
mensuplai unsur hara yang dibutuhkan tanaman.
Defisiensi UNSUR MIKRO pada tanaman kentang telah banyak
dilaporkan dan dikaji di berbagai daerah.
Research have been conducted to evaluate the response of potato
to added UNSUR MIKRO under any local conditions.
Small plot studies were carried out at CSIDC to examine the
effects of soil and foliar applied B, Cu, and Zn on the
productivity and quality of seed and consumption (table or
processing) grade potatoes.
Tanaman kentang untuk produksi bibit merrespon aplikasi UNSUR MIKRO
secara berbeda dengan tanaman kentang untuk konsumsi, karena ia dipanen lebih
awal dan ukuran umbinya lebih kecil dibandingkan umbi untuk konsumsi.
Trials were conducted on an irrigated sandy loam soil with no previous history of
UNSUR MIKRO use.
The concentrations of UNSUR MIKRO used in these studies were based upon
commercial recommendations.
Soil applications included, 1.6 kg B/ha (1.44 lb/ac) in the form of granular Borate,
10 kg Cu/ha (9 lb/ac) in the form of Copper chelate, and 10 kg Zn/ha (9 lb/ac) in
the form of Zinc sulphate broadcast on to the seedbed prior to planting.
The foliar treatments included 0.3 kg B/ha (0.27 lb/ac), 0.5 kg Cu/ha (0.45 lb/ac),
and 0.5 kg Zn/ha (0.45 lb/ac) applied as a foliar spray at the time of early tuber
bulking.
The sources of the foliar UNSUR MIKRO applications included commercial
formulations of liquid Boron, Copper chelate, and Zinc EDTA.
Pengaruh pH Tanah terhadap Ketersediaan B, Cu dan Zn.
HASIL APLIKASI PUPUK MIKRO LEWAT DAUN
Neither soil-applied nor foliar-applied B, Cu or Zn affected seed or
consumption grade yields, specific gravity, or fry colour of
processing cultivars.
The lack of any significant yield or quality responses to UNSUR
MIKRO supplements is likely due to the presence of adequate levels
of UNSUR MIKRO in the soil.
For example, soil testing to 30 cm (12 in) in the spring of 1997
showed that the soil contained 4.4 kg B/ha (4.0 lb/ac), 3.4 kg Cu/ha
(3.1 lb/ac), and 2.4 kg Zn/ha (2.2 lb/ac). Recommended soil levels for
potato production are 1.1 kg B/ha (1.0 lb/ac), 0.4 kg Cu/ha (0.4
lb/ac), and 1.1 kg Zn/ha (1.0 lb/ac).
Pengelolaan hara-pupuk menjadi bagian kritis dalam suatu
ushataani kentang yang berhasil .
The use of UNSUR MIKRO supplements should be based on soil
tests, tissue tests and close visual examination of the potato crop for
deficiency symptoms.
Growers should carefully follow recommendations for UNSUR
MIKRO to avoid unnecessary costs and possible toxic effects or
deleterious interactions with other nutrients.
Selection of an effective application method depends on the UNSUR
MIKRO needed, local soil conditions, and the stage in the growing
season at which a deficiency is detected.
Diagnosa Defisiensi Hara
Gejala Defisiensi yang Umum
A first step in diagnosing nutrient deficiencies is to describe what the symptoms
look like. Each deficiency symptom must be related to some function of the
nutrient in the plant.
Symptoms of nutrient deficiencies are generally grouped into five categories:
1) Pertumbuhan kerdil;
2) khlorosis;
3) interveinal chlorosis;
4) warna merah-keunguan
5) nekrosis.
Stunting is a common symptom for many deficient nutrients due to their varied
roles in the plant.
Unsur hara tidak mobil
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