Sep 19, 2014
Home| Tools| Events| Blogs| Discussions| Sign UpLogin

CornCollegeBanner home

January 2014 Archive for Ask an Agronomist

RSS By: Farm Journal Agronomists, Farm Journal

Have your agronomic questions answered by a Farm Journal agronomist. E-mail us directly at, and we’ll respond on this blog to provide an interactive dialogue.

Are soybean seed inoculants something I should consider?

Jan 30, 2014

Question: What’s your experience with inoculant use in soybeans?  I’ve never used one and am considering it this year.

Answer:  We have done a lot of work with soybean seed inoculants here in Michigan, and I’m in favor of using one. What we’re seeing with inoculant-treated beans is that we get more nodules sooner than what we have with untreated beans.  Why is this important?  Because nodules make nitrogen, and soybeans use a lot of nitrogen.  Typically, nodules start forming right after emergence, but they don’t start working for the plant until around V3, when the first three trifoliolate leaves are fully developed.  When you have an inoculant out there, we have seen those nodules start working a little bit sooner.  If it’s cool and wet and we need nitrogen in that plant, we’ve seen an inoculant help in that situation quite a bit. We think the inoculants are pretty economical for the return on investment they provide.  Some of the newer products stay on the seed for a long time, as much as 120 days, and maybe even longer for the newer ones.  I would encourage you to do your homework on these products.  While this isn’t always true, you tend to get what you pay for, and there is quite a range in these products that are available today.

Bean Booster

Inoculants can lead to a more robust soybean root structure, better nitrogen fixation and more yield potential. About 50% of soybean seed in the U.S. is treated with a commercial inoculant, and that’s trending up.

What’s the difference between site of action and mode of action for weed control?

Jan 21, 2014

Question: What’s the difference between site of action for weed control and mode of action? I know figuring this out can help me address weed resistance.

Answer: This is a good question, and one I’m getting more often. Mode of action (MOA) tells us what effect the herbicide will have on the plant. Site of action (SOA) tells us what pathways the herbicide will use to inflict that damage. The goal in preventing weed resistance is to regularly change what pathways are being attacked within the plant by choosing herbicides with different SOAs. By choosing different SOAs, the mutated or resistant plants can be killed before they reproduce, stopping resistance from spreading. It is important to note that choosing products with different active ingredients is not enough; you must make sure that your rotation of products contains varying SOAs. One other consideration, in an attempt to change up the MOA or SOA, applicators and farmers are going to be using products that have not been all that common in the past decade. Be careful, in the process of using different products, that you don’t increase drift problems or carryover issues in the field, and follow all label recommendations. 

Weed Warriors: Location, Location

Farmers who wrestle with tough-to-control weeds know all too well the importance of rotating herbicide chemistries, or using multiple modes of action. Multiple herbicide sites of action is also important to understand.


Using Cut Rates for Herbicide Application

Many farmers will be in the field hoping to control winter annual weeds this week. Use caution before turning to a cut-rate herbicide application.


Herbicides By the Numbers

Simplify the chore of herbicide rotation by using the numbers that are located on most herbicide labels.

Where can I get a soils map?

Jan 07, 2014


Question: I have been reading your series about making zone maps. It says to start with a soils map. Where can I get a good soils map?

Answer: You may be able to get a hard copy of your county soil survey from your local NRCS office. I’d also encourage you to visit the NRCS soil survey site:

Management Zones Keep Soil Fertility In Check Map your fields by soil type and track pH, phosphorus and more, Farm Journal associate field agronomist Missy Bauer tells Corn College TV Season 3.

Four Ways to Improve Soil Health These tips will keep your fields producing at their highest potential.

Farm by the Foot Start with a soil survey and go out with GPS and confirm its accuracy.


Log In or Sign Up to comment


Hot Links & Cool Tools


facebook twitter youtube View More>>
The Home Page of Agriculture
© 2014 Farm Journal, Inc. All Rights Reserved|Web site design and development by|Site Map|Privacy Policy|Terms & Conditions