Couldn't find the old thread that addressed this so here's a new one.
This from little ol' p = Pioneer
Manganese Fertilization of Soybean
Manganese (not to be confused with the macronutrient
magnesium) is one of the 16 elements essential to plant growth
and production. Since this element is needed in relatively small
amounts compared to others such as nitrogen and potassium,
manganese is considered a micronutrient.
Manganese has several very important roles in the plant,
including its function as an activator or cofactor of at least 35
enzymes. Manganese is part of the structure of an important
antioxidant (superoxide di****ase) that protects plant cells
by deactivating free radicals, which can destroy plant tissue.
Manganese plays vital roles in photosynthesis as a structural
component of the photosystem II water-splitting protein. It also
serves as electron storage and delivery to the chlorophyll reaction
Manganese is suffi cient in most soils to supply crop needs,
but may be defi cient in dry conditions, sandy soils, high organic
matter soils (especially peat and muck), and soils with high pH.
When defi cient, manganese can be supplied by fertilizer in several
forms, by foliar and soil-applied methods.
Of all micronutrients, manganese tends to be the most
common defi ciency noted in soybean production. Manganese
defi ciencies, however, tend to respond positively to remedial
treatments of manganese (when they are timely). As with all
nutrients, yield responses are only attainable when manganese
is defi cient and therefore limiting yield. This article describes
manganese requirements, defi ciency symptoms, soil and plant
sampling, and fertilization practices in soybean production.
Chemical Properties and Availability of Manganese
in the Soil
Manganese exists in a number of forms in the soil, including
soil solution Mn2+, exchangeable Mn2+, organic compounds,
various minerals, and as other ions. However, the only form
known to be plant available is the manganese ion Mn2+ in soil
solution. Manganese availability to plants largely depends on
soil texture, organic matter, pH, and weather conditions.
Soil pH – Manganese is most soluble and therefore available
to the plant at a pH of 5 to 7. In alkaline soils (pH above 7),
manganese may form insoluble compounds, making it unavailable
to the plant. For every increase of 1 pH unit, manganese
availability decreases 100-fold. In very acidic soils, however,
manganese can reach toxic levels. Liming soils to appropriate
pH can help avoid this situation.
Soil Organic Matter – Organic matter and manganese ions
will combine to form insoluble compounds that are not accessible
by plant roots. This is exacerbated by high soil pH.
Soil Aeration and Moisture – Available manganese is affected
by soil aeration and moisture. Waterlogged and anaerobic
(or “reducing”) environments are conducive to more Mn2+
in solution. In contrast, very dry soils tend to have less Mn2+ in
soil solution. Additionally, low moisture conditions will slow the
growth and activity of soil microbes that also cycle manganese
in the soil.
Weather Conditions – Hot and dry conditions result in less
manganese in available form as they typically cause dry soils.
Other Nutrients – High levels of copper, zinc, and iron can
reduce uptake of manganese. Conversely, acid-producing fertilizers
including ammonium sulfate, MAP, and DAP can increase
manganese availability. Potassium chloride (0-0-60 potash) may
also increase plant uptake of manganese.
Manganese Defi ciency Symptoms in Soybean
Visual defi ciency symptoms include interveinal chlorosis
(yellowing between the veins) on the younger leaves, followed
by necrosis (brown/black spots of dead tissue) and yield loss if
the defi ciency progresses.
Figure 1. Manganese defi cient soybeans. Uppermost (youngest) leaves
show interveinal chlorosis while the veins remain green.
(Photo courtesy of Ron Gehl, NC State University)
Areas of defi ciencies will likely vary across the fi eld, and
since the availability of manganese is tied to soil factors, knowing
the fi eld’s history over time can be helpful in diagnosis.
Fields or fi eld areas with a history of manganese defi ciencies
will be more likely to show defi ciencies in future soybean crops.
Figure 2. Manganese defi ciency on a muck soil near Lansing, MI.
(Photo courtesy of Ron Gehl, NC State University)
Soil and Plant Analysis for Manganese
Because yellowing of plants can be due to a number of
factors (iron, potassium, or magnesium defi ciency, herbicide or
insect injury, soybean cyst nematode damage, poor nodulation,
etc.), good scouting practices and tissue sampling are often
needed to confi rm a specifi c nutrient defi ciency. Plant tissue
analysis is the usual method to confi rm a suspected manganese
defi ciency, as soil testing tends to be much less predictive.
Plant Sampling – The standard plant sampling technique
for soybeans is to take the newest trifoliate leaves that are fully
opened (keeping in mind that manganese is not very mobile and
new leaves will show defi ciencies). Randomly sample plants
to get a representative sample of the affected area, though
consider a separate sample of non-affected plants to make
a comparison. When sampling leaves, remove the petiole (or
stem-like structure that holds the leaf to the soybean stem) so
just leaf tissue is represented in the sample. Be sure to follow
your diagnostic laboratory’s specifi c sampling and shipping
jabber: Good post. But, it is pretty common knowledge that glyphosate ties up Mn...in the tank...in the plant...and in the root zone. There was a PhD at Purdue doing some excellent work on this, but he retired. Big M prolly forced it. lol.
Boy this has been a ***** to post up the damn thing was to long so this will be page one ,Just hope I can find the other half ! Ken
Dr. Don Huber's presentation
Written by Jim Martindale
With full credits to Dr. Huber and Jerry Carlson
Jerry Carlson's Notes from Dr. Don Huber presentation Dec. 16, 2009
High yield hybrids: More N must be taken up after tasseling. Also,
high yield corn can use ammonium better, as opposed to nitrate
nitrogen. 75% ammonium, 25% nitrate N.
NServe takes nitrous ammonius out of the rhizosphere. Other
organisms fill the void about 9 days.
Glyphosate takes entire groups of organisms out of the soil.
Biological buffering becomes very difficult when you have a compound
that persists in the soil for years.
About 80% of our nitrogen losses are conversion to nitrous oxide, and
volatilization. Not leaching, which occurs only in sandy soils.
A lot of our ag chemicals are chelators. Tordon chelates copper.
Glyphosate is a powerful chelator for many ions.
There’s ten tons of living material in an acre of soil. It’s a
living entity and the quality of its life impacts mineralization of
Manganese availability depends on biological activity; it can only
use Mn2+ and not Mn4+ Most bio availability occurs between 5.2 and
Take-all in wheat is a manganese converter. Amplify the take-all
fungus with carbon and energy, it amplifies its growth.
Filaments of Take-all coat themselves with Manganese Oxide, MN04.
Take-all ties up manganese and can impact the following crop.
Improved nutrition reduces disease. Manure on wheat stimulates
resistant to rhizoctonia.
Copper deficiency: Ergot on wheat, produces LSD.
Ergot sclerotia -- closes the capillaries.
Closest I’ve seen in my 55 years to a prolonged recovery period from
the impact of glyphosate.
Inserting the RR gene in plant reduces Mn uptake efficiency. It adds
a stress on the plant’s physiology. Another system is running in the
plant. If you have a good mineral soil with lots of buffering, the
loss of efficiency may not hurt yield much. But in a MN-deficient
soil, yield could suffer and really bomb out. This is why many of
the soybean varieties are off the market.
In soils that 15 years ago we were concerned about manganese
toxicity, we’re not seeding manganese deficiency because we’ve
changed the soil microflora so much with glyphosate applications.
Iron, manganese available to plants only in reduced form (H).
Sulfur only available in oxidized form.
Gypsum gives you a good source of soluble CA plus soluble Sulfur.
Converting nitrate nitrogen into amine form, amino acids, can take
16% of the energy (sugars) built by the plant. This is why high-
yielding corn needs a 75% ammonium form of N, and 25% nitrate form.
Fusarium wilt in melons and fruit -- go for Nitrate form and calcium.
Recognizing nutrient disease interactions with Glyphosate
Canadian: I’ve seen all those symptoms, just never associated them
Going to glyph, we changed tillage and crop sequence too.
Learn to watch for the symptoms; there’s a limited way the plant can
Single most important indicator of head blight is use of glyphosate
in the past three years.
Glyphosate was patented as a metal chelator. Monsanto patented as a
herbicide. Needs ammonium sulfate in the tank to tie up metals and
minerals. Binds minerals -- Ca, Cu, Fe, Mg, Mn, Zn.
EDTA is a chelator of 13.
Glyphosate penetrates readily, moves throughout the plant, chelates
with minerals and it’s not available for the plant from then on.
Micronutrients tied up won’t be available for any future growth.
About a fourth of the glyphosate is exuded from the root system.
Once the initial flashing is over,
There is 1,000 times more glyphosate in the vascular system than
there is unbound minerals. There’s an abundant supply of glyphosate
to chelate all minerals in the plant for about two weeks.
There’s an 80% reduction in Mn uptake.
Translocation of Fe, MN, Zn from root to shoot is reduced by more
than 80%. Once it’s chelated it doesn’t move.
Chelating means bonding. EDTA turns loose of minerals eventually,
glyphosate does not.
Liberty Link has degradation within a two-day period.
All of the degredation products of glyphosate are toxic to the plant,
even the RR resistant plant.
100% of the kill of plants with glyphosate is to open a secondary
pathway for microbial organisms.
Chelation of micronutrients -- accentuates drought stress. Three-
fourths of the gly moves to shoot, repproductive and roots.
About a fourth of the gly moves into the soil via living roots.
We don’t know of any organism that uses gly as a nutrient source.
It sits there and accumulates for several years. It’s toxic to N-
fixing microbes, Mycorrhizae, Earthworms, PGR organisms, Mycorrhizae,
Bacterial shikimate pathway.
We are starting to see glyphosate in grain, such as wheat planted
after glyphosate crops.
In Humans, we need a lot of micronutrients too.
Mandated phosmet insecticides chelated copper in cattle in England,
and there was an outbreak of BSE.
There may be some organism found to break it down, but haven’t heard
Glyphosate is an amino acid; it looked like it would biodegrade.
However, the French forced Monsanto to take “biodegradable” off the
label because they couldn’t demonstrate it.
USDA shows mineral content of conventional and GMO grain is lower
Bob Kremer, University of Missouri, analyzes gly in the soil. Lab in
Pennsylvania tests for metabolic degredation products.
The compound hangs around a long time, both in the plant and in the
In the soil, desorbed by phosphorus.
Directly toxic to N-fixers
When you put glyphosate out, you kill them.
All organisms with shikimate pathway are inhibited.
Richard Dick at Ohio State -- stimulation of fungus can immobilize up
to 150 lbs. of potassium.
If the politics win with the 15-year glyphosate review, we’ll see a
continuing degradation of our productive base. This is already
evident in the Pacific Northwest, where it’s hard to get a decent crop.
China has moved into RR cotton, they’re struggling.
We’ll have to import more food unless we reverse course on GMO/
When you’re in the hole and keep digging, it doesn’t do much good.
We should use it a lot more judiciously.
RR sugarbeets have very little resistance to rotting in the pile.
They last two weeks. But being judicious would help; you don’t need
a gallon of glyphosate on sugarbeets.
Glyphosate tolerant weeds are finding other pathways, not just the
manganese which is an enzyme inhibitor.
We have aphid invasions because the amino acid is more appealing to
aphids, stimulating the aphid population.
Alfalfa -- 20-ft. taproot. Could be translocating glyphosate into
the water table.
We’ve had a 1500-fold increase in herbicide use, primarily because of
glyphosate’s advertising as environmentally friendly.
We’ve ignored the challenge. Now we’re approaching the consequences.
I have a tremendous confidence in using the abilities to use the
knowledge the Lord has given us.
Bottom line is that glyphosate stimulates fusarium, nutrient
oxidizers, and soilborne pathogens.
Texas -- corn fails after glyphosate cotton . Shikimate test out
the top. Lots of 100% failures. Across the road, Non-gmo corn doing
great. How many insurance claims will the federal insurance program
allow on this basis?
Have 50 years of failure on biological control of crop diseases on
My only successes were in building desert soils with biological
Davies spent his whole career into trying to reduce pathogens in
soils with biological organisms.
Within six hours, you have colonization with pythium. In just six hours.
Whole groups of organisms disappear in a glyphosate environment.
Glyphosate reduces lignin content of soybeans. Also reduces amino
acid content of soybeans.
Reduces water efficiency. Takes twice as much water to produce a
pound of dry matter.
Phil Jones, 8200 paired trials, presence of RR gene imposes a yield
drag. There’s another genetic system for the plant to support. So
we have two negative impacts: soil impact plus gene impact.
How would I get rid of it? Will the RR gene transfer to unintended
crops and weeds? That was the basis for the alfalfa injunction... in
five years, all alfalfa would be RR. Brazil is looking for ways to
help farmers pull back from RR genetics in corn and beans.
Desorption of glyphosate with phosphate: Re-releases the compounds
in glyphosate and has a greater chelation effect.
Sudden Death Syndrome in soybeans is definitely related to the rise
of fusarium in RR soybeans.
Barney Gordon, Kansas. Gene present reduced yield effectivness. Took
additional manganese to offset the presence of the gene.
Jeff Neal, journalist in England... had written story about myth of
Tissue tests may show adequate Mn, Zn, but doesn’t reveal if it’s
chelated with glyposate in the plant and therefore ineffective for
Mineral reduction in RR crops:
RR treated beans 45% lower in Mn, 26% lower in Ca.
Dan Skow, veterinarian with International Ag Labs in Fairmont, MN,
says they’re adding more manganese to dairy rations because of the
deficiency in soy protein.
Vet: Brazilian corn tests in 2005 were much lower in fusarium molds;
if Brazil has lower mold counts than the U.S. over time, where should
the Japanese buy?
Soil organisms kill the weed, not the glyphosate itself. That’s what
happens when you shut down the shikimate pathway. In effect,
glyphosate is our 24th worst disease.
Diseases increased by Glyphosate.
Many of those which were controlled in the past are coming back.
And many of the wilts and other fungi are losing host specificity,
and are impacting more crop species as well as becoming more virilent.
Wait 8 days before spraying manganese to remediate the lack of
manganese. What’s happening is that glyphosate is being released
and ties up applied manganese.
Manganese carbonate as a treatment to remediate manganese tied up.
When you have an iron defificency in the soil, you have a manganese
(My side note: In high iron soils of the southeast, maybe there’s
abundant Mn and little yield drag. .. perhaps that’s involved in high
yield response to SoySoap in the Southeast while we see muted
Tree trunk is a highly absorptive area for glyphosate
Here's another good one from ISU also a two parter ! After reading this I thing I have a good idea what Kip is up to , LOL Hope I can get the other part . Ken
Iowa State University Weed Science 1 [url]www.weeds.iastate.edu/mgmt/2010/glymn.pdf[/url]
IOWA STATE UNIVERSITY Weed Science
University Extension Department of Agronomy
Glyphosate-Manganese Interactions in Roundup Ready Soybean
Shortly after the introduction of Roundup Ready (RR) soybean questions arose whether these varieties and/or glyphosate applications to them alter manganese (Mn) relations compared to conventional soybean varieties. It is well documented that certain cations, including Mn, can reduce the performance of glyphosate when the cations are present in water used as a carrier. The complexes formed between glyphosate and metal cations are not absorbed as efficiently as free glyphosate alone, resulting in reduced weed control. The primary role of AMS used with glyphosate applications is to minimize formation of the cation-glyphosate complexes. This article will review research that has investigated the interactions between RR soybean and Mn relations, rather than what happens in the spray tank. Although the focus of this article is Mn, glyphosate would interact similarly with other cations (e.g. calcium, iron, magnesium).
Mn efficiency of soybeans with Roundup Ready trait
Some of the first reports of Mn-related problems with RR soybean were reported by researchers at Purdue University in 2001 (Dodds et al. 2001). They found that growth of a RR variety grown on a Mn-limiting soil was inhibited more severely by Mn deficiency than a conventional variety. On a non-limiting soil there was little difference in growth of the two varieties. The research was repeated in 2002 using additional varieties, and some, but not all, RR varieties were found to be more sensitive to Mn-deficieny than conventional varieties (Dodds et al. 2002). Gordon (2007), at Kansas State University, reported that under a high-yield environment a RR variety was responsive to Mn fertilization whereas a conventional variety was not. Based on this research, it could be concluded that RR varieties are less efficient at Mn absorption/utilization than conventional varieties. However, due to the limited varieties evaluated in the studies, it is just as likely that the difference in response to Mn between the RR and conventional varieties was due to some other difference among the varieties rather than the RR trait. The 2002 Purdue study included several RR varieties and found that not all RR varieties were responsive to Mn, suggesting that the Mn response is not directly linked to the RR trait. Research in California found no evidence that the RR trait affected Mn relations (Rosolem et al. 2009). Research in Brazil found 1 out of 3 RR varieties had lower Mn concentrations in new leaves than the non-RR parental line, but the other two varieties were not affected (Zobiole et al. 2010).
Interactions of glyphosate and Mn within soybean
A second issue with glyphosate and Mn is related to interactions between the two molecules in the plant, rather than the characteristics of RR varieties. An injury response often seen following glyphosate application to RR soybean is chlorosis in newly emerged leaves. The symptoms are similar to those attributable to Mn deficiency, so it has been implied that glyphosate may interfere with Mn relations within the plant. Glyphosate is poorly metabolized by plants and accumulates in growing points, and can accumulate at concentrations capable of forming complexes with Mn or other metal cations. Zobiole et al. (2010) reported that glyphosate applications decreased Mn and other nutrient concentrations in RR varieties. They also reported significant reductions in shoot and root biomass due to the glyphosate applications, something that is normally not observed. However, the majority of research has not identified differences in Mn absorption, accumulation and availability between glyphosate-treated and non-treated RR soybean (Bott et al. 2008; Rosolem et al. 2009; Nelson 2009). Rosolem et al. (2009) stated that glyphosate injury symptoms in RR soybean have been misinterpreted as Mn deficiency. Ebelhar and Hart (2006) in Illinois were unable to prevent chlorosis associated with glyphosate by supplementing soybean with additional Mn, nor prevent yield loss associated with high
Iowa State University Weed Science 2 [url]www.weeds.iastate.edu/mgmt/2010/glymn.pdf[/url]
glyphosate rates (2X-4X) with supplemental Mn. While the chlorosis that appears following glyphosate application mimics Mn deficiency, the symptom has been attributed to accumulation of AMPA in new leaves (Reddy et al. 2004). AMPA is a degradation product of glyphosate.
Interactions of glyphosate with Mn in the soil
It has been speculated that glyphosate may interact with Mn relations by reducing availability of Mn in the soil via chelation. It has also been suggested that glyphosate could reduce the availability of soluble Mn by affecting the activity of microorganisms that control the oxidation-reduction status of soil. Glyphosate may enter the soil profile either by direct contact during spraying or through exudation from roots of treated plants. Glyphosate released into the soil has been shown to affect growth of microorganisms in the vicinity of the roots and in the zone of application (Kremer et al. 2005), but there are no published data documenting reduced soil availability of Mn or other nutrients. While it is possible that glyphosate could temporarily tie up essential elements, it would not specifically target Mn, or any other micronutrient, but rather would interact with the most prevalent cations in the vicinity of the roots. In Iowa soils, the majority of glyphosate would likely interact with the highly abundant Ca and Mg rather than Mn, and also organic matter. Furthermore, levels of Mn in Iowa soils probably are sufficient because there have been no reports of Mn crop deficiency symptoms in Iowa. Crop Mn deficiency symptoms occur in some regions, and this is where interactions between glyphosate and Mn nutrition have been reported.
So the question is whether RR soybean varieties require different Mn management practices than conventional varieties and if this is really a problem under Iowa conditions. Glyphosate is known to form complexes with Mn and other metal cations that may reduce both the availability of the cation and glyphosate activity. However, most interactions between RR soybean and Mn have been observed in areas with soils known to be deficient in Mn. Although there has been research indicating RR soybean may respond differently to Mn than conventional varieties, the majority of research does not support this observation. The best recommendation remains to manage RR soybean similar to conventional varieties in terms of fertility management.
Prepared by: Bob Hartzler
February 24, 2010
Bott, S., T. Tesfamariam, H. Candan, I. Cakmak, V. Römheld, and G. Neumann. 2008. Glyphosate-induced impairment of plant growth and micronutrient status in glyphosate-resistant soybean (Glycine max L.). Plant Soil 312:185-194.
Dodds, D.M., Huber, D.M. and M.V. Hickman. 2002. Micronutrient levels in normal and glyphosate-resistant soybean varieties. Proc. North Central Weed Sci. Soc. 57:107.
Dodds, D.M., M.V. Hickman, and D.M. Huber. 2001. Comparison of micronutrient uptake by glyphosate resistant and non-resistant soybeans. Proc. North Central Weed Sci. Soc. 56:96.
Ebelhar, S.A. and C.D. Hart. 2006. Soil, pH and manganese effects on yield of Roundup Ready soybeans. Ill. Fert. Conf. 2006:54-65.
Gordon, B. 2007. Manganese nutrition of glyphosate-resistant and conventional soybeans. Better Crops 91(4):12-13.
Kremer, R.J., N.E. Means and S. Kim. 2005. Glyphosate affects soybean root exudation and rhizosphere micro-organisms. Inter. J. Environ. Anal. Chem. 85: 1165-1174.
Nelson, N. 2009. Manganese response of conventional and glyphosate-resistant soybean in Kansas. Insights: Inter. Plant Nutr. Inst. South. Centr. Great Plains Reg. July: 3.
Reddy, K.N., A.M. Rimando, and S.O. Duke. 2004. Aminomethyl-phosphonic acid, a metabolite of glyphosate causes injury in glyphosate treated, glyphosate resistant soybean. J. Agric. Food Chem. 52:5139-5143.
Rosolem, C. A., G.J.M. Gabriel, I.P. Lisboa and S.M. Zoca. 2009. Manganese uptake and distribution in soybeans as affected by glyphosate. Proc. Inter. Plant Nutr. Colloq. XVI. [url]http://www.escholarship.org/uc/item/3f53794z?query=Mn[/url] soybean
Zobiole, L.H.S., R.S. de Oliveira Jr., D.M. Huber, J. Constantin, C. de Castro, F.A. de Oliveira, and A. D. Oliveira Jr. 2010. Plant Soil 328:57-69.
Acknowledgements: This article was reviewed by Mike Owen, John Sawyer and Antonio Mallarino.