Monday, June 25, 2012

The drought's effect on soybeans will become a concern soon here and across the United States.  If you have a good stand, the big impact will be at pod fill if we don't get timely rain.  Most fields around here have decent stands but some are lacking and there is no moisture to sprout double crop soybeans.  Those acres are minimal in Ohio this year and not too important unless you are the one depending on that income.

"Soybean is susceptible to yield loss from water deficit, drought stress, at two key developmental stages, germination and reproduction-seed development. Soybean must imbibe about 50 percent of its weight in water to germinate and begin to develop the radicle and hypocotyl, the primary root and shoot tissues. Seed planted into dry soil, or not placed into the soil, will be unable to imbibe water at all until adequate precipitation has occurred. Soybean can respond to water deficit as early as two days after germination. Water deficit at this time results in poor hypocotyl elongation, while root elongation may be unaffected.

Drought stress at later vegetative stages of development has similar results: shoot growth is decreased or stopped, but roots can continue to grow. This evolutionary response in soybean allows the plant to search for additional soil water while having an overall low water use rate. Assuming adequate rainfall occurs again, soybean have the ability to reinitiate shoot growth, and shoot growth rate may be greater than that observed prior to the onset of drought stress. This is called compensatory growth.

Short-term, moderate drought stress during vegetative growth stages generally does not impact soybean yield. Conversely, longer-term severe drought stress can cause irreversible plant cell death causing low growth yield.

Soybean yield is most sensitive to water deficits during reproduction. Soil water deficits during reproductive growth phase results in increased flower abortion, reduced pod number, reduced seed per pod, and small seed. Nitrogen fixation is a key biochemical pathway for soybean yield and nitrogen fixation can be severely limited or completely halted by even moderate drought stress. Once nitrogen fixation has been stopped, substantial precipitation and soil water accumulation is required to reinitiate the process. Compensatory reproductive growth rarely will occur in soybean under moderate drought stress at reproductive growth phases.

Management practices that leave low amounts of residue on the soil surface or cause compaction can reduce soil water infiltration rate. Excessive or poorly timed tillage can cause soil compaction and increase water runoff from high intensity storm events. Reduced compaction and increased water infiltration rate can increase soil water content, nitrogen fixation, and soybean yield, particularly during growing seasons with less than adequate precipitation."

Nitrogen fixation seems to be limited at this time.  Soybeans are too yellow to suit me this year.  They probably needed some supplemental nitrogen at planting time to get them going good.  We saw one black green soybean field northeast of Paris, Illinois Saturday and I would assume the farmer knifed on anhydrous, got rained out and planted soybeans later.  Everything else from Maryland to Illinois have been less green, most are accetably green but many are too yellow.

Mother Nature once again has the upper hand on soybean yields.  It will take water after flowering to make an acceptable yield.

The picture shows what my beans looked like two years ago. It never rained much after the picture that year and they made a tremendous yield but we don't have anything that looks like that this year.

Ed

13 comments:

  1. This is really interesting, You are a very skilled blogger.
    I have joined your rss feed and look forward to seeking more of
    your great post. Also, I have shared your website in my
    social networks!

    Here is my website :: diets that work fast for women
    Also see my web page - safe diets

    ReplyDelete
  2. Unquestionably believe that which you said. Your favorite reason seemed to be on the internet the easiest thing to be aware of.
    I say to you, I definitely get annoyed while people think
    about worries that they just don't know about. You managed to hit the nail upon the top and also defined out the whole thing without having side-effects , people can take a signal. Will probably be back to get more. Thanks

    my blog post: NFL Jerseys Cheap

    ReplyDelete
  3. I have read so many content concerning the blogger lovers except this post is in
    fact a fastidious post, keep it up.

    my web blog Louis Vuitton Handbags Outlet

    ReplyDelete
  4. I need to to thank you for this fantastic read!

    ! I absolutely enjoyed every bit of it. I've got you bookmarked to look at new things you post…

    My site :: Abercrombie Et Fitch

    ReplyDelete
  5. You've made some really good points there. I checked on the web to find out more about the issue and found most people will go along with your views on this site.

    Feel free to visit my blog post; Oakley Holbrook

    ReplyDelete
  6. I pay a visit every day some web sites and websites to read articles or reviews,
    however this blog provides feature based writing.

    My blog :: Louis Vuitton Pas Cher :: smu-fr.org ::

    ReplyDelete
  7. I always spent my half an hour to read this website's posts every day along with a cup of coffee.

    Feel free to surf to my web site :: Nike Blazers Shoes

    ReplyDelete
  8. Thanks for every other informative blog.
    The place else may I am getting that type of info
    written in such a perfect means? I've a mission that I am just now operating on, and I've been on the look out for such info.


    Here is my blog post :: Nike Air Max

    ReplyDelete
  9. What a data of un-ambiguity and preserveness of valuable experience regarding unexpected emotions.


    Feel free to visit my page - Nike Trainers

    ReplyDelete
  10. Hey would you mind sharing which blog platform you're using? I'm going to start my own blog in the near future but I'm having a tough time selecting between BlogEngine/Wordpress/B2evolution and Drupal. The reason I ask is because your layout seems different then most blogs and I'm looking for something unique.
    P.S Sorry for being off-topic but I had to
    ask!

    My site Louis Vuitton Handbags

    ReplyDelete
  11. Please let me know if you're looking for a article writer for your weblog. You have some really good posts and I think I would be a good asset. If you ever want to take some of the load off, I'd love to
    write some articles for your blog in exchange for
    a link back to mine. Please send me an email if interested.
    Thanks!

    Here is my web-site :: Air Jordan Pas Cher ()

    ReplyDelete
  12. Great information. Lucky me I recently found your site by
    accident (stumbleupon). I have saved it for later!

    Here is my web page; Mulberry Outlet UK

    ReplyDelete
  13. This site was... how do you say it? Relevant!! Finally I have found
    something which helped me. Thank you!

    My blog post :: Find Out More

    ReplyDelete