Air December 6 - 12, 2006
Potential Cold Injury to wheat
This is Ag Outlook 2006 on 1420 KJCK, I'm Chuck Otte, Geary County, K-State Research and Extension Ag & Natural Resources Agent. Well we certainly got a taste of winter temperatures recently, and even though winter isn't officially here yet, we were reminded of what to expect. So now the question has to be, did those cold temperatures hurt the wheat. We had slightly above normal temperatures for November so a lot of wheat hadn't really had a chance to go dormant and get hardened off. It went there in a hurry around December 1st! We wouldn't be having this conversation had we gotten even a little bit of the snow that they were talking about. We got none of the white stuff and so no insulation. On top of that, a lot of the wheat went in late and was small, it was also growing in dry soils. Dry soils get cold deeper and faster because there isn't the soil moisture there to buffer the rapid temperature change. On top of the cold weather we had some wind. Wind can cause a lot of problems through dehydration of plant tissues. Now that I've given you all that bad news, let me give you a little good news. Even small wheat plants have some pretty good winter hardiness in the fall. Wheat with two or more leaves can generally handle temperatures in the 0 to 5 degree range. Maximum hardiness is going to occur with somewhat larger wheat and usually from mid-December to early February. Most of the low temperatures around here were in that 10 to 12 degree range. Had we gone down to zero or below zero, we could have had some real problems. We will have some scattered damage from these cold temperatures, but for the most part, I think we escaped it this time! This has been Ag Outlook 2006 on the Talk of JC, 1420 KJCK, I'm Chuck Otte.
Topdressing Wheat Decisions
This is Ag Outlook 2006 on 1420 KJCK, I'm Chuck Otte, Geary County, K-State Research and Extension Ag & Natural Resources Agent. Okay, all your wheat is planted, and hopefully up by now. And sometime in the next ten weeks you are probably going to topdress your wheat. Soil temperatures are certainly cool enough now that we wouldn't expect to lose much to denitrification or even ammoniation loss. While some folks like to wait until late winter or early spring, just prior to jointing, this practice may be in question as head development may already be too far along to make much of an impact just prior to jointing. As long as the ground isn't frozen, and you don't need to apply a herbicide that would require you to wait until late January or February, the sooner you can get the wheat topdressed now, the better. Of course, the next question is, how much nitrogen do we need to apply. Well, the most economic answer is going to come from doing a good profile nitrogen test so that we know what is out there. Some soil test studies this fall have shown an average of 85 pounds of profile nitrogen in wheat fields. BUT the range was 8 pounds to over 200 pounds. So you can gamble and hope that you have the average or above and go light on the nitrogen, but what happens if your field was more on the 8 or 10 pound range? Think about this, wheat needs 2.4 pounds of nitrogen for over bushel of yield. 60 bushel wheat needs 144 pounds of nitrogen. Some will come from organic matter breakdown, roughly 10 pounds per percent. Some might come from manure applications or a previous legume crop and the rest will come from residue N or fertilizer. Even if you have thin stands or small stands this fall, do not back off on the fertilization. It's a risk, you just can't take! This has been Ag Outlook 2006 on the Talk of JC, 1420 KJCK, I'm Chuck Otte.
Fertilizing brome and fescue
This is Ag Outlook 2006 on 1420 KJCK, I'm Chuck Otte, Geary County, K-State Research and Extension Ag & Natural Resources Agent. Just as we have talked about this being the time to start fertilizing wheat, the same can be said for fertilizing bromegrass or fescue. And while I may talk about bromegrass in the rest of this program, you can treat fescue the same way. A soil test about 30 days prior to fertilization can tell us a lot about your forages fertilizer needs, but I can tell you right now that most brome fields are NOT getting the nutrients they need. In addition to nitrogen, we also need annual applications of phosphorus and probably some sulfur also. In older fields we may also start to see a need for some potassium, believe it or not. In recent years, rainfall has been unpredictable and it quite honestly has been a challenge to justify the fertilizer that we have been applying. But if you just assume that it's going to be dry and you don't apply adequate fertilization, then regardless of what happens with rainfall, you will become a self fulfilling prophecy of poor brome yields. If you are only cutting the bromegrass for hay, then about 100 pounds of nitrogen will probably be adequate. If you are trying to graze it some also, then an extra 20 to 40 pounds may be justified but this needs to be applied in a separate application. Phosphorus rates need to be based on soil test, but if you don't want to pay for that soil test, plan to apply 30 or 40 pounds. Then also throw in ten pounds of sulfur. Several of our commonly used fertilizers used to have quite a bit of sulfur as a contaminant, but no longer and we are starting to see nice responses to sulfur. As for timing, you can probably go on with that anytime, but most definitely by January or early February. This has been Ag Outlook 2006 on the Talk of JC, 1420 KJCK, I'm Chuck Otte.
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