Irrigated Soybeans............

[eddiedry]

Subtle differences, the left side from the bonnet to the well at the opposite end just got a drink, the right side is still thirsty.

[glowplug]

Nitrogen (N) Deficiency

Soybeans go through a period when their leaves are a light-green
color before the nodules supply adequate nitrogen (N) and a
dark-green color returns. If proper nodulation, sufficient nutrients,
and moisture are present, soybeans can recover from this yellow
phase fairly rapidly as the season progresses (Figure 1).
Nitrogen deficiency can be identified as a yellowing or chlorosis of
the lower leaves in the canopy as N is remobilized to the new
growth. The two sources of N available to the plant are the soil
and N fixation. The first choice for a N source is the soil. This
process requires less energy compared with N fixation. The
nitrogen taken from the soil can account for up to 50% of the total
nitrogen needed for growth.

-----------Some time back, we were having a discussion on the "other" list speculating as to how Cullers and others were making those record soybean yields. My opinion was that yields are being limited by the amount of N the plant could fix and supply itself with. Cullers has never totally revealed his "secret sauce" in his irrigation. I still believe he's supplementing N along with the sugar - Headline content stuff. Methinks the soil isn't simply feeding enough N at the time where beans are putting on yield.

Go ahead and tell me where I'm FOS cause I got a thick hide. Or not........
Glowplug

[Dave-ECIA]

I've suspected the same thing. Some studies a while back didn't show much of an increase in yield for N supplemented soys, but they were putting it on pre-plant.

Always wonder how they would fare if it was applied at R1 or so. Make them fat and happy when the pod size determination happened.

I'm noticing on my own beans that they were setting 2 bean pods during the heat/dry period when the lower pods were setting. We got a rain when the middle nodes were setting pods and I'm finding 3's and a few 4's. The tops are just starting to set pods and I'll know in a week what happened there.

Without the rain, I have no doubt in my mind they would have continued to set 2's.

[glowplug]

We've always been told that pre-plant N made beans lazy welfare recipients because they wouldn't make as many N fixing root nodules because the N is there without working for it.

Adding N when the plants really need more N than they can fix themselves to build yield would seem to be logical. Won't be a year here for top bean yields. Some of mine are standing in water right now.

Glowplug

[kwestfarms]

Beans in my area of Cent. Wis. ( Clark Co. ) look excellent at this point in time. Good color , height , and Lots of nodules on plants I have checked. Still a long way to go before combines roll. John