# Manganese deficiency



## FarmerCline (Oct 12, 2011)

I have been seeing some yellowing on the leaves in some of my crops. I first noticed it on the oats back in the spring. I suspected it may be a manganese deficiency from the symptoms but wasn't fully sure. Now the same yellowing showed up on the pearl millet I planted in the same field as the oats as well as a few fields of soybeans. I sent off tissue samples last week and they did come back as manganese deficiency. The agronomist I talked to said that manganese deficiency was a sign of too high ph. I told him that I had been liming my soils to build them up to 6.5-7. He said that was higher than recommend and didn't suggest over 6.2 for soybeans. I told him that I was also growing alfalfa and needed the ph to be higher than that. He was unsure what to suggest as he wasn't familiar with alfalfa as there is pretty much no one else growing it around here. It was recommended that I spray a foliar manganese on the crops now that are showing a deficiency but that won't do anything for future crops. What could I do to build the manganese in my soils but keep the ph where I need it? Could I use dry manganese blended with the NPK blend I usually use?


----------



## Thorim (Jan 19, 2015)

Saw this don't know if it will help your situation.

http://www.ncagr.gov/agronomi/MNSSSNC.htm


----------



## FarmerCline (Oct 12, 2011)

Thorim said:


> Saw this don't know if it will help your situation.
> 
> http://www.ncagr.gov/agronomi/MNSSSNC.htm


 I hadnt seen that article but have read one that was similar but not as much info. Much of the info on that is similar to what the agronomist said about the ph. I'm not in a coastal plain soil however like the article says is normally where manganese deficiencies are found. The problem I see is it says that for a broadcast application to help that the soil ph needs to be lowered and I need to keep my ph higher than 6.2 since I also grow alfalfa. NC doesn't have much of any info on alfalfa fertility since so little of it is grown in the state. I guess I could always try a broadcast application to see if it will improve the manganese availability to the crop.

I should also add that I noticed today I think I'm starting to see some places of manganese deficiency in alfalfa as well. Won't know for sure until I send off another tissue sample.

I was just curious if anyone else had trouble with manganese deficiency where they keep the ph up to 6.5-7 for alfalfa in the rotation.


----------



## Vol (Jul 5, 2009)

My soils have stayed around 6.8 for as long as I can remember.....I do have yellowing at times but it is because of Sulphur deficiencies....which is easily remedied with adding S to my fertilizer. I would be very curious to know if others in your county have Manganese problems? I would pull some soil samples and have them macro/micro tested and specifically for Manganese and Sulphur.

Manganese deficiency seems a little odd in the foothills of the mountains.....very uncommon.

Regards, Mike


----------



## BWfarms (Aug 3, 2015)

Don't jump too quickly!!!

It can be a few things. Could be phosphorus binding that is choking the soils ability to utilize iron (or could be an actual iron deficiency). Remedy this by not putting out as much phosphorous next year. Could be nitrogen washed out or water logged plants because we've had a lot of rain. Here's a chart that will confuse you even more.

http://www.nutrite.com/ressources_sheets/Nutrient%20Deficiency%20Symptoms.pdf

Just soil sample the actual spot around the plants roots.


----------



## FarmerCline (Oct 12, 2011)

Here is the results of the tissue test I sent on the pearl millet. It came back as a manganese deficiency. I haven't sent off a sample of the alfalfa yet. Doubt it is sulphur though since I spread 25 pounds a few months ago. http://www.ncagr.gov/agronomi/PALS/Reports/viewReportDetails.aspx?Param=1068475$$1$$2$$0$$P000284

I haven't heard of anyone else in the immediate area that has had a manganese deficiency but they don't lime there soil to keep the ph above 6.5 like I do. Im going to ask the county extension agent if he has heard of anyone else that has seen manganese deficiency.


----------



## Hugh (Sep 23, 2013)

I would keep liming to raise the pH, and foliar spray manganese, which will then be supplied to the soybeans regardless of the soil pH.


----------



## Hugh (Sep 23, 2013)

P.S.

"On-farm research at Rutgers University in New Jersey illustrates the differences between broadcast and foliar applied Mn on alfalfa. Broadcast soil applications of 20 lb. Mn/ac from manganese sulfate, applied once in the spring at the start of new growth, and was compared with foliar treatments of 0.5 lb of Mn/ac applied foliarly before each harvest when the plants were about 6" tall. Compared to the untreated control plots, the soil application of 20 lb Mn/ac increased the season's yield by 0.2 T/ac, while the foliar treatments increased the yield 0.4 T/ac. While these may not seem like dramatic increases for the foliar treatments, remember that the foliar program required significantly less Mn.

The researchers noted that foliar applications may be made more cost-effective by combining one or more sprays with a pesticide application. They also suggested that a combined program may be even more cost effective. For example, a spring soil application of 10 lb Mn/ac, made with other fertilizer, followed by several foliar applications during the remainder of the year may be best in some situations. It should always be noted that you should check the compatibility of all products when combining them in spray solutions.

Having worked with high soil pH situations for many years, we have found that it often requires more than the 0.5 lb Mn/ac in foliar applications to satisfy the crops needs. Various sources suggest foliar Mn application rates from 0.5 to around 2 lb Mn/ac. The low end of this range may be ineffective in some situations, while the high end could cause tissue damage. If a high rate is planned, try an application on a small area to see if leaf damage occurs.

*As you can see, we do not recommend broadcast applications of Mn.* However, as we have seen, high rates of broadcast Mn can have positive results. It should be understood that the high rates of broadcast Mn rarely increase the soil Mn levels or availability. Therefore, the crop will nearly always require those high rates annually over the life of the stand. Given this situation, it seems more reasonable to depend on foliar Mn applied during each alfalfa regrowth period." From Spectrum Analytic.

Notice the above: "high rates of broadcast Mn rarely increase the soil Mn levels or availability." I'm betting this would apply to soybeans as well, so I say spray Mn. Good luck!


----------

