Corn Seeding Rates

Choosing the proper population on corn will help you maximize yields and protect your bottom line. Our old recommendation was to plant a maximum of 30,000 seeds/acre on better soils. We will increase that recommendation to about 33,000 seeds/acre for better soils. But, as our own data shows, picking the ideal seeding rate can be a bit of challenge. Available water has a huge impact on the ideal seeding rate.

In 2008, a year that was very dry, the ideal population for corn was less than 20,000 seeds/acre, well below our current recommendations. Our yields barely reached 120 bu/acre and we felt really stupid about growing corn. In 2009, a year with timely rains, the ideal population for corn was at least 45,000 seeds/acre, well above our recommendations. Our yields rose above 300 bu/acre and we felt really smart. However, the only major difference between the two years was the amount and timeliness of rain. In both years, we used the same four hybrids, the same soil type and the same fertility. (If I told you that we got 300 bu/acre of corn with 160 lbs N/acre, no one would believe me. So, I'm not going to say it.) When you "average" the two years together, yield was maximized at about 35,000 seeds/acre. Both of these years were extremes and we rarely advise farmers to make decisions based on the extremes.

Even more evidence about the influence of water on seeding rate comes from a study we conducted in 2007 at the Woodford County Farm. The rainfed corn reached a maximum yield at about 30,000 seeds/acre where the irrigated corn reached maximum yields above 40,000 seeds/acre (Figure 2). The irrigated corn received water at rates that were probably too high for most traditional sprinkler irrigation units to deliver. Five years of research on a Maury silt loam suggests that maximum yields are reached at about 30,000 to 33,000 seeds/acre (data not shown).

So, if water is not limiting, then much higher seeding rates may be suitable. However, most years in Kentucky, water is our limiting yield factor. Our soils are relatively shallow and can hold just a few inches of water at a time. Almost every year, we go through a period of two to three weeks with no water and high temperatures during seed fill. It is this period that probably does more to limit yields than most other factors each year.

As we see more and more center pivots come into Kentucky, I think we need to do some more investigation in this area. Again, the center pivots will not irrigate as well as our small-plot system. But, these center pivots can help farmers avoid extremely dry weather. If farmers have an interest in running some strips as high as 40,000 seeds/acre, I would be interested in talking with them.

For the vast majority of acres without irrigation, a maximum seeding rate of 33,000 seeds/acre on better soils does a good job of avoiding the extremes.

Figure 1. Yield response of four hybrids on a Loradale silt loam soil, Lexington, KY.

Figure 2. Seeding rate study on a Maury silt loam, Woodford County, KY, 2007.

Keeping up with Argentina

If you have an interest in some of the things I am seeing in Argentina, you can take a look at a separate blog, Argentina Update. This blog is a rough draft of my notes. I will include as many images as since they tell a better story. I will keep notes on the crop progress, agronomics, farm management, and groups and organizations that help producers.

Crops from Way Down South

The full season soybeans are in pod stage and the corn is about 1/2 milkline. Yield potentials are excellent as long as it doesn't rain too much over the next month.

This probably seems like an odd report in the middle of winter, but it is exactly what we are seeing down south. . . in Argentina. A group of farmers from the Kentucky Soybean Board and UK extension faculty visited with farmers, agribusiness representatives, university scientists and students for about one week. During that week, we met some wonderful people. Some even apologized to us for not being able to speak English well... and we're in their country.

We also saw a tremendous crop. However, that crop has a little way to go. Last year, this region of Argentina had its worst drought in 100 years. This year, the crop may ultimately suffer from too much rain. Farmers here are nervous about getting their crops harvested, since rains typically increase over the next month. Some things are universal since farmers back in the States do the same when they see a good crop in the field.

We visited some of the more productive soils in Argentina, including northern Buenos Aires Province, south Santa Fe Province and southeast Cordoba Province. One of the farmers we visited said that typical annual rainfall is about 45 inches, but over the last two months his farm in this region received nearly 38 inches! Other regions of Argentina are in a drought this year.

While my colleagues are heading home, I'll be here a few more months. I plan to give some brief reports during my stay... including how the crop looks.

Grain Storage and Drying Calculators

A lot of the grain harvested this fall was wet. Immediate sale of this grain resulted in dockage at the elevator. On-farm storage and artificial drying of the grain also has costs. Now that farmers have most of their grain out of the field, they can pay closer attention to how much on-farm storage is costing compared with the expected dockages at the elevators.

An excellent website on Grain Storage was has several calculators to help producers estimate the costs of drying grain, grain shrinkage, grain bin capacity, and related topics. Dr. Sam McNeill, Extension Agricultural Engineer, was the author of most of these calculators.

A related website for Proper Grain Storage and Handling includes additional relevant topics.

Over the last few years, commodity marketing has been incredibly challenging for producers, largely due to a major increase in price volatility. This increase in price volatility signals a changing marketplace and has affected how many producers feel about using the futures’ market to manage price risk. One factor that has changed is the addition of new futures’ market participants. The purpose of this article is to define and describe one of these new participants – the commodity index trader. Commodity index traders take long positions (i.e., they buy futures) and purchase an index, or a basket of different commodities. Commodity index traders are more important today than ever, as they represent traditional stock market investors who are now diversifying their portfolio in the commodity market. Currently commodity index traders represent about 22% of open interest for corn and 24% of open interest for soybeans, which means they have a significant impact on market direction.

Commodity index traders view the return to commodities as negatively correlated with stock market and bond returns, and positively correlated with inflation. Therefore, the investment portfolio is viewed as being better balanced if it includes exposure to commodities in addition to stocks and bonds. The commodity index trader enters the futures market for exposure to commodities for the long-term. Positions are rolled from one contract month to the next, using a predetermined methodology. As a result, their actions are not based on reacting to fundamental supply and demand signals, but rather are a function of this predetermined method.

A commodity index trader can be classified as being either commercial (i.e., a hedger) or noncommercial (i.e., a speculator). A commercial commodity index trader manages hedges of cash transactions – private transactions that are not traded on an exchange. A non-commercial commodity index trader represents pension funds, endowment funds, and other institutional investors. A non-commercial commodity index fund is both passively managed and unleveraged.

Figure 1 shows the percent of open interest (i.e., the number of futures and options contracts that have not been settled) held by commodity index funds for corn. Commodity index traders, as a percent of open interest, ranged from almost 30% in April 2006, to just fewer than 15% in December 2008. For the last week of October 2009, commodity index traders represented almost 25% of open interest. Figure 2 illustrates the percent of open interest held by commodity index traders of soybeans; interest ranged from 30% in July 2006, to just less than 20% in October 2008.




During the commodity price run up in spring/summer of 2008 the percentage of open interest did not increase relative to other positions. In fact for corn, the percent of open interest by commodity index traders decreased overall during 2008. For soybeans a slight overall increase in percent of open interest occurred during 2008. Understanding their purpose and how they work will help the producer in making better hedging decisions in the future. (Cory Walters, cgwalters@uky.edu)

Soybean Reports Now Available

The Kentucky Soybean Performance Test is available online.

The report is linked to the Grain Crops Extension home page and the University of Kentucky Variety Testing website.

The soybean varieties are divided by maturity and compared in one of four studies:
1) relative maturities 2.7-3.0
2) relative maturities 4.0-4.5
3) relative maturities 4.6-4.9
4) Maturity Group V

Table 5 reports the all location average and is the recommended table for making variety selections.

Printed reports likely will be available at your county extension office in three to four weeks.

Corn Hybrid Performance Report

The 2009 Kentucky Corn Hybrid Performance Report is now available online. You can access the publication at the Variety Testing Website or at the Grain Crops Extension home page site.

There were six locations for the tests this year with early (112 days or less), medium (113 to 117 days) and late (118 days or more) maturity tests. In addition to those tests, white corn hybrids and hybrids for ethanol production were evaluated in separate tests.

 A hybrid that performs well across multiple envrionments has the best chance of performing well next year on your farm. Use the data from the tables with yields averaged across locations. Compare the data from this test with data from local tests and select hybrids that have done well in both.

If you have questions about hybrids in the test, please contact your county extension agent.