Why Is Some corn yellow-green?

[Fergienewbee]

Driving by a corn field today, I noticed some plants to be a very dark green and others more yellow-green. My first thought was water, but being in the same field they should get as much each time it rains. Is it soil fertility or a fertilizer problem?

Larry in Michigan

 

[Don-Wi]

Water. Feilds can and do vary, and some spots are always just a little lower so those spots hold water and the plants get too much in those spots.

Donovan from Wisconsin

 

[Anonymous-0]

I have saw that also. Think the man that put on the nitrogen skipped some spots.

 

[Keith in NW MO]

The wetter the ground it ties up the Nitrogen so that it isnt available to the plant. It has nothing to do with the guy spreading the fetilizer.

 

[twopop]

dont know anything about the soil in mich. but the lack of iron will turn corn yellow

 

[cadet trooper]

As Keith stated usually a sign of too much rain causing denitrofication where the rain has washed away the nitrogen and also when corn was planted in too wet of conditions in clay type soil that ties up the N.

 

[dwrk]

Can be a fertilization problem but more often water. Often when it looks like "streaking" you're actually seeing the effect of tile drainage at work. I've seen a couple of years where we could see where the tiles were by the colour of the corn.

 

[kyplowboy]

If it's round sppts more than likely it is low spots in the field that hold h2o. If its streaks every 30' like some one else said, it's between the tiles. If it is small corn and real narrow streaks it could be that some plants have reached the NH3 and some have not. This will fix it's self when the yellow plant's roots get deeper.

Dave

 

[Anonymous-0]

Pretty much a synopsis of what the others said- too much water in the low areas, nitrogen leaches down, is unavailable, or the roots have not grown deep enough to reach the nitrogen that is still there. Roots are generally about as deep as the above-ground growth- we've seen a lot of that here, wetter areas of the field have slower growing plants, and as the weather gets better, the roots deepen, and the crop gets green. m We're still behind a normal year, but with warm weather, it will catch up. Just like purple corn in the spring- takes heat units to recover.

 

[Allan in NE]

Yep,

That “yellow” is a dead ringer for Nitrogen deficiency for whatever the reason.

See that a lot after a field has been leveled and the process gets down into the clay/subsoil. Also on “knob” areas where there is a high gravel content.

Will see it sometimes to a certain extent in corn following wheat too. That heavy straw/stubble has an effect of tying up the N.

Don’t know about the “too-much-water” deal. Have never had that problem. :>)

Allan

 

[Hugh MacKay]

Keith: I beg to differ with you, yet I agree most of it is drainage. There is few fields about two miles from me, and I saw the bozo with a new 8000 series Deere doing the side dressing of N. It now shows up he missed from 1 to 3 rows each pass, and those 1 to 3 rows are quite yellow. I can't quite figure how he matched with planter, as he never skipped the same number of rows each time.

I didn't see it planted, however I suspect it was an 8 row planter and he was sidedressing with a 6 row unit. Planter operator must have been quite accurate between passes. I will say this much, bozo didn't seem to be damaging many plants. He may have started off same pattern as planter, however by half way across field he's off by half.

 

[Hugh MacKay]

Allan: Here in the east where we get 36" plus annual rainfall, and I suspect you'd call this excessive moisture, we have two unique problems, yet both are nitrogen and both are drainage. I suspect MI is not a lot different from SW ON.

First is a wet year when it continues to stay wet all growing season and the moisture can tie up N, make it not available to the plants. This will usually be spotty as many of these fields don't have uniform drainage.

The second situation is wet at planting time then turns dry as season progresses. Because the water table is high at planting and shorthly thereafter, corn establishes very shallow root system. It comes in dry about end of June, water table drops, and at that time corn has it's root set, and I'll be darned if we can get it going again to follow the moisture down.

Our answer is tile under drainage, sufficient to keep that perminant water table down 36", thus we get much healthier root systems. This spring and summer have been excessively wet, not uncommon to see 6" to 12" high corn having parts of a field completely submerged in water for several days. A systematically tile drained field will get rid of that excess moisture much faster. Lighter soils will drain faster as well. Of course the down side to fast drainage is N leaches away much faster as well.

I went by a field other day heavy clay, corn was all stunted in the low areas of field. One could tell parts of this field had be submerged, maybe more than once. You could also see ruts 12" deep, from side dressing in these wet spots.

And you think of lack of moisture being the problem to deal with. We don't have the kind of problems IA suffered a few weeks back, however we also don't have a Mississippi flowing through the area. Rivers around these lakes are quite short, thus we don't have to deal with up stream neighbors water very often. What falls on the area is what we get.

 

[RayP(MI)]

Larry, I spend quite a bit of time on the road in central Michigan. This year, there was a lot of "spotty" corn. Some with stunted growth, some with yellow color, even purple! Often the corn in the same field was uneven, and different colored. I think that the rain, soil conditions, and temperature variations lead to this. Corn seems to be recovering a bit now, as we"re getting warmer weather.