JenREES 9-13-20

Will miss catching up with people at Husker Harvest Days this week! Virtual field day at:

Grateful for the rain! It provided a break, the end of irrigation, and will help with settling dust and hopefully reducing fire risk. Here’s wishing you a safe harvest as it resumes! May see some soybean shatter. Was hearing reports of soybean moisture ranging from 9-11% over Labor Day weekend on 2.0-2.5 maturity beans. Saw non-irrigated soybean fields in Nuckolls/Webster county area that died with the leaves still attached. The previous week’s heat with the lack of moisture for so long was just too much.

One area on-farm research study is a soybean maturity study. This is the third year for this study and after harvest we’ll have 9 site-years worth of data. The objective is to determine yield and economic impacts from planting 2.0-2.5 maturity beans vs. 3.0-3.5 maturity beans in April to early May. Planting a range of maturity groups can aid in spreading out harvest; we’ve found about 1 day delay for every 0.1 in maturity group. Planting a variety of maturity groups can spread risk regarding timing that heat and moisture (or lack of) are received (especially for non-irrigated beans). There’s also increased interest in earlier maturing varieties for seeding a cover crop for erosion and/or weed control or increased biomass for grazing. Our data thus far has found genetics to be the bigger yield factor as there’s high yielding genetics regardless of 2.0 to 3.5 maturing varieties.

The soybean yield equation is more complicated than determining yield for corn with final yield harder to predict. This is what it looks like followed by an example with numbers that Dr. Jim Specht shared:

[Plants/Acre X Nodes/Plant X Pods/Node X Seeds/Pod] / [Seeds/Pound X Pounds/Bushel] = Bushels/Acre

120,000    x      21    x     2      x     2.4       /     [  2500      X      60   ]    =    81

Plants per acre is often less instrumental for yield as it’s inversely related to total number of seeds per plant (high population=less seeds/plant, low pop=more). We had more soybeans planted early in the area this year than I’ve ever before experienced. Early planting allows for increased nodes per plant. This year many remarked on plants being loaded with flowers; this could be partly due to the abundant sunshine. On average, Dr. Specht assumes 2 pods/node; there’s some nodes loaded with pods this year and we need to watch how they finish filling. A soybean pod contains, on average, 2.4 seeds, primarily because the 1-seed, 2-seed, 3-seed, and 4-seed pods produced by indeterminate soybean plants tend to occur in respective proportions of 10%, 40%, 50%, and ~0.1%. These proportions can vary somewhat among varieties.

As we think about the soybean yield equation, seed size (seed mass) is the component most impacted by lack of August rain or ending soybean irrigation too soon. This ranges from small (3750) to large (2250) seed/pound with most varieties today averaging about 2500 seed/pound. Last week’s rains will most likely help group three soybeans with seed size and reducing additional seed abortion.

Soybean Quality Study: The Nebraska Soybean Board and some researchers from UNL are asking farmers to help with a soybean quality study. I have sample jars in my office and all that’s required from you is to take 3 samples from a non-irrigated field and 3 samples from an irrigated field (not field corners). They will share results with the growers who participate. Please contact me at or 402-440-4739 if you’re interested in participating!

Overseeding Lawns can still occur as late-August through mid-September is the best time to seed bluegrass and fescue. Fescue really shouldn’t be seeded any later than this but bluegrass can be into later September if needed. It’s really important to get good seed to soil contact by preparing the seedbed. The following publications from Nebraska Extension provide step-by-step instructions: Improving Turf in Fall and Establishing Lawns from Seed. Buy blue tag certified seed from a reputable dealer.

Explore Beekeeping free webinar will be held on September 24th from 6-8 PM. The speaker will address how she uses bees on her family farms in conjunction with pollinator cover crops and fruit trees. This program will be offered in English and Spanish. Participants can register online at

About jenreesources

I'm the Crops and Water Extension Educator for York and Seward counties in Nebraska with a focus in irrigated crop production and plant pathology.

Posted on September 14, 2020, in JenREES Columns and tagged , , , . Bookmark the permalink. Leave a comment.

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