Field Notes from Kip Cullers

Question: What kind of yield can we expect without rain since about mid-June?

Kip: Yield estimations are nearly impossible to make without being able to see the field. However, there are several things that you may want to consider. First off, droughty soil conditions prior to tassel can have a significant impact on pollination success within your field. Silks, which are composed mostly of water, are significantly impacted by a lack of water. This can cause the timing of silk emergence and pollen shed to be out of sync. Secondly, drought conditions can cause the most significant kernel abortion from just after pollination up through roughly early to mid-milk stage. As kernel development approaches late milk to early dough, kernel losses become less of a problem, while poor kernel fill issues become the primary concern.

Based on where you are located (Russell, Minnesota), I would assume that your drought conditions were occurring prior to tassel. You may want to go out and gently peel back the husks on some ears and determine the pollination success of the ears. Carefully pull the husks off without disturbing the silks and give the ear a gentle shake. If all of the silks fall off easily, you have had good pollination. If some of the silks are still attached to the ovules, then you have had a few issues with reduced pollination. From there, it is just a matter of receiving timely rains so that you do not lose kernels through early ear development and so that you can increase kernel depth and density as your crop approaches maturity. Good Luck!

Question: Do you use a soil applied fertilizer source with your beans and if so, what are you applying? Also how many times and at what stage are you applying foliar fertilizer to your beans?

Kip: We do not use any soil-applied fertilizer sources on soybeans other than the poultry litter we put on in the fall. This gives us all the P&K we need plus, N, also. We put on foliar applications of ammonium sulfate to supply N and S during pod development and pod fill. Generally we put on 3-4 applications of foliar N during these growth stages depending on the year (weather) and crop appearance.

Question: On your contest fields, what is your total fertilizer applied and when do you think it is best applied N-P K? We do a lot of strip-till in the fall, but because of wet weather last fall, we had some spring strip-till this year and it is probably my best looking field. I wonder why the spring strips look better than the fall?

Kip: My nitrogen program is different from what a lot of corn producers use in other states in that I do not rely on anhydrous ammonia or 32% solution as my primary N source. I supply most of my N (plus P and K) in the fall applications of poultry litter that I use. So, during the growing season, I will supplement with some ammonium sulfate through the center pivot irrigation system, but not more than 10-20 lbs N per acre in a single application. Because of the tillage we need to use to incorporate the litter, strip till is not really an option for us here.