Agronomy Notebook

I am in Ukraine on a training mission to assist growers here in growing better corn and soybeans. One question that keeps coming up is, “What is the right seeding rate for soybeans?” Some of them have told me that it’s 1 million seeds per hectare. I think in terms of 1 million for wheat, but a hectare is 2.47 acres, so 1 million is 405,000 seeds per acre — still too high. Take into account that they use brown bag seed, so add maybe 20% due to reduced quality seed — still too high. And oh, by the way, this brown bag seed seems to tolerate very high levels of “gleefosat” herbicide applied over the top.

I give them the same answer I do when the question comes up in Ohio — we need about 100,000 plants per acre at harvest to achieve full yield. You just calculate backwards to determine your losses to germination percent, emergence, disease, insects, crusting, excessive moisture, etc.… Continue reading

We will be discussing the proven methods you can use to boost corn yields this year. I am sure you are already using most of these ideas. I challenge you to pick at least one idea that fits your farming practices and try to improve it.

• Use minimum or no-till — especially on erodible land. It helps in conserving moisture loss reduces soil erosion and minimizes compaction.

• Set a realistic yield goal — It should be based on your soil type, organic matter and historical data. Goals based on 2012 or 2013 alone will be unrealistic. So you may want to use last five-year average as a guide.

• Study yield maps — Analyze your yield data field by field with your Seed Consultant and try to Match hybrids with soil types.

• Do soil tissue tests — These tests should be conducted at the right time and the advice of the consultant followed.… Continue reading

Compaction that occurs below the soil surface is even more important than surface crusting. It is hard to diagnose and can cause serious yield losses if not corrected. Soil compaction can occur throughout the growing season and can cause poor crop growth.

• If the soils are wet, tillage implements can cause soil compaction just below the depth of the operation.

• Large farm equipment like tractors, manure spreaders, trucks, planters and combines can cause compaction within the root- zone, especially, when the soils are wet.

• If tillage operations are always performed at the same depth, a hardpan can develop just below the depth of tillage operation. Weight of the tillage machines can cause compression of the soil particles causing compaction.

• Wet soils, especially those with higher clay content are more likely to develop a hardpan. The depth of the compacted layer can be determined by slowly digging and moving the soil with a shovel and exposing the top of the compacted layer.… Continue reading

What are the causes of soil compaction?

Soil compaction is one of the most important factors that can affect soil health and reduce crop yields. In the early 1980s, Purdue University soil scientist Gary Steinhardt and Ohio State University Ag Engineer Randall Reeder were making farmers aware of the compaction problem and its effect on yield reduction. Compaction may be caused in many ways. We need to diagnose the reasons for compaction before corrective measures can be taken. Surface compaction can occur from the impact of rain drops or in the form of crusting due to excessive rains and ponding. It may also be caused by the impact of irrigation water.

• If the soil is left bare and is exposed to hard rains or irrigation water, the impact of water breaks down the larger soil aggregates and the granular structure of the soil on the surface are degraded, causing compaction.… Continue reading

Corn growers know the satisfaction of seeing newly emerged, uniform rows of green corn plants set against the backdrop of dark, rich soils. By contrast, it can be painful to see an uneven stand from the truck window when driving past a field.

The cause of an uneven stand could be excess crop residue in the planter row.

“Corn residue will delay and outright interrupt plant establishment, and suppress the resulting plant population,” said Andy Heggenstaller, DuPont Pioneer agronomy research manager. “Corn residue is always a management issue, and high-yield production systems increase residue levels.”

Stand establishment is more of a challenge for corn than it is for soybeans, because corn is typically planted earlier, into cooler and wetter soils. Also, soybeans can accommodate reduced emergence by adding additional pods to make up for yield that could be lost from lower plant populations. That’s why hitting optimum corn plant population levels is so important.… Continue reading

Just when we thought we knew virtually everything about growing corn, scientists keep on finding new things about growing this amazing crop. Most farmers plant corn seed between 2 to 2.5 inches deep. However, new evidence suggests that we should be planting corn seed even deeper.

• Research studies conducted in Indiana recently found that it may be better to plant corn even deeper rather than shallower to get more consistent results. Generally, deep means 3 inches or more and shallower means less than 1.5 inches.

• Paul Jasa, an Extension Ag Engineer for the University of Nebraska indicated that his research with no-till planting indicated that corn should be planted at around 3 inches depth, particularly in continuous no-till planting. They got more consistent results from deeper plantings than shallower planting. In their continuous no-till trials in Nebraska, corn planted three inches deep yielded 217 bushels per acre, and corn planted 2.25 inches deep yielded 199 bushels per acre.… Continue reading

I am a strong proponent of early planting. This year early planting may not have helped but it did not hurt either. Why is earlier planting so important and how does it work?

• The easiest and least expensive way to make greater use of the free solar energy, without too much extra cost in machinery and with the currently available hybrids, is by planting early.

• It is an established fact that in most situations, early planting produces higher yields. However, the reason for higher yields is not explained. It has to do with the sunlight!

• We know that the longest day of the year in northern hemisphere is June 21st. During the two months period, from May 21 to July 21, we get more sunlight than any other duration of this length in the year. We can capture the greatest amount of sunlight if we plant early enough to have a full canopy by May 21.… Continue reading

Many things can affect test weight. Some of the important factors that can influence test weight are listed below:

• Genetics of the hybrid plays an important role in test weight of the grain. Planting hybrids with genetic potential for higher test weight will generally yield grain with higher test weight if the kernels are fully mature.

• Early planting helps hybrid maturity and leads to higher test weight. Our studies for several years indicated that corn planted before May 10 had 1 to 1.5 pounds higher test weight than late May or June plantings.

• Lower grain moisture will have higher test weight since the kernel dry matter is heavier than water. Test weight is a volume-weight relationship. Drier grain shrinks and has higher test weight because we can pack more kernels into a “bushel basket.”

• Higher temperatures after the physiologic maturity or black layer tend to increase the test weight if kernels are mature.… Continue reading

It seems that fields with weed problems are more of the exception rather than the rule this growing season. Herbicide resistant weeds are also a growing problem.

To address the issue, some farmers are stepping up their weed control efforts to try and stay ahead of the problem.

“I think we have some weed issues, with marestail being No. 1,” said Doug Longfellow, who farms in Darke County. “Even though we had really good control early, I am looking across 15 acres of beans right now and I can see a couple dozen marestail plants that escaped. It looked good through summer until the soybeans started dying and these marestail started to emerge. We still have work to do, even though I thought we had a good program. I think the solution is going to be part cover crop and part a double application of 2,4-D in the fall and the spring.… Continue reading

I know that most Ohio growers are already in the field busy with harvest. However, I thought it would be appropriate to remind growers of the importance of monitoring harvest losses throughout the harvest season, not just the first few days. We know that losing some grain during harvest is inevitable but measuring that loss behind the combine can pay big dividends to those who make adjustments during harvest. The combine owner’s manual is the best place to start in making sure that you don’t leave grain in the field above the normal and acceptable loss.

Every bushel of soybeans or corn left behind by the combine represents a loss in profits. While harvest losses cannot be completely eliminated, timely combine adjustments can reduce losses to 1 or 2 bushels per acre.

Measuring soybean harvest loss

To determine soybean harvest losses, count the number of beans on the ground in a 10 square foot area.… Continue reading

As harvest continues around Ohio is it no secret that many growers are seeing strong numbers on the yield monitors, with many of the readings pushing the 200-bushel mark.

That is, of course, great news for farmers around the state, but it does bring some things to think about for Bill Mullen, Director of Agronomic Services for Seed Consultants.

“One of my big concerns with these big yields is the trash that will be left on the field,” Mullen said. “This leaves a very good supply of nutrients, but we’ve got to break it down from the stalks.”

As many visitors noticed at Farm Science Review, there is new technology out there that may help with this issue and many options to choose from, including some non-conventional .… Continue reading

Soybean producers can easily get an idea of the yield potential of their crops with a Purdue Extension soybean specialist’s calculation method.

Soybean yield potential is built on many factors, including the genetics selected, management decisions during the season and the weather. Yield components of soybeans are pods, seed size and number of seeds per pod.

“Individual plant production varies, and every field will vary based on pests, soils, fertility and other factors,” said Shaun Casteel. “But I’ve simplified the process of estimating soybean yields so that producers can scout multiple areas quickly while maintaining representative estimates.”

Casteel’s system is based on estimated yield in one ten-thousandth of an acre. The basic formula involves multiplying the number of pods by the number of seeds per pod, then dividing that result by the seed size factor. That calculation will show the estimated bushels per acre.

To calculate, producers first need to count the number of pods in one ten-thousandth of an acre, an area determined by a 21-inch length of a row of plants and how far apart the rows were planted.… Continue reading

Across Ohio, the corn crop in general is set up for high yields based largely on ample amounts of precipitation and moderate temperatures during most of the 2013 growing season. Lately, rainfall has been at a premium with some areas receiving adequate moisture and others needing a good shower to finish the crop. The questions that remain are, will my corn crop mature and what should I be looking for prior to harvest? This update attempts to address both of those questions.

Overall GDU (heat) accumulation during 2013 is currently below normal across most of Ohio. As a result, corn grain fill, drydown and harvest maturity are delayed. Prevailing weather conditions between now and harvest will dictate how fast field drying will occur versus harvesting at higher moisture and using artificial drying methods for the corn crop. The rule of thumb, based on research conducted at Ohio State University, is that field drying rates of standing corn range from half to three-quarters of a point of moisture per day up until mid-October, and decline to a quarter to half a point until early November.… Continue reading

After lot of rain in April and May and a late start in planting, I was hoping that this growing season might turn out to be alright, but it has turned hot and dry. I guess we can’t count our chickens until the Fat Lady, Mother Nature, has sung her final tune! What are the effects of stress during the grain-fill period?

• After pollination we need 50-60 days, depending on the relative maturity of the hybrid, for the grain-filled period. This is when the plants’ primary focus is to fully develop the kernels.

• If there is severe heat or moisture stress during the grain-fill period, the plants start to cannibalize their leaves and stalks to fulfill the growing needs of their progeny.

• Plants, like animals, don’t want to produce runts. So, if there is stress during the grain-fill period, the plants start to abort the youngest kernels causing tip die-back so the remaining kernels can fully develop.… Continue reading

Are we going to have wet corn this year? I am afraid so, unless you were able to plant early. We are facing the following scenarios this year for corn yields and maturity:

• Rains in April and May delayed corn planting in most of the Corn Belt.

• Weather has been cooler than normal and we are at least 12 to 15 days behind normal and about 20 days behind last year, if corn was planted by May 15. Corn planted in late May and early June has just finished pollinating.

• After pollination, It takes 45 to 50 days to reach maturity.

• When planted late, corn hybrids require fewer growing degree days to reach maturity than earlier planted corn if the temperatures are near normal in July and August.

• The yields are generally higher when it is cooler because the plants have a longer grain-fill period. The plants just live longer in cooler weather and yield more but that delays reaching physiological maturity or 32% kernel moisture (black layer).… Continue reading

We have talked about corn leaf diseases and foliar fungicides in this space recently but we need to watch out for insects also. Some of the important insects that might “bug” us are discussed below:

• Corn rootworm beetles larvae attack the roots during June and early July and the adult beetles clip the silks and may interfere in the pollination process during July and early August. Watch out for these insects if you are growing GMO corn where the trait has failed or the non-GMO corn if you have not used insecticide.

• Japanese beetles have copper and green color and eat the green silks as well as leaf tissue. Adult may be found during July and August.

• European corn borer larvae are dirty white to tan with dark spots and a dark brown to black head. Young larvae feed on the leaves. Before tasseling the larvae feed deep inside the leaf whorl and produce shot holes.… Continue reading

Ohio corn growers have a pretty good looking corn crop to date. Growth and development has been fast and furious as the corn has had all the heat and moisture for excellent growth. Many areas of Ohio have had 17 to 19 inches of rainfall since April 1 and we have accumulated near 1,700 Growing Degree Days since May 1. Most of the corn crop was planted the first 10 days of May. Bottom line is, we are ahead of normal for heat unit accumulation and rainfall. Due to the excellent condition of corn, many of these acres have had a fungicide application to protect the genetic

potential of the corn crop.

Although it has been very hot and humid, pollination has progressed at a normal pace and kernel set looks good. Here are some facts about corn pollination that has taken place in your fields.

Pollination and fertilization of the embryos is one of the most important stages of corn crop development.… Continue reading

Corn needs a lot of tender loving care throughout the growing season and to raise a successful crop, it needs special attention during the following critical stages:

• At seedling emergence, young plants face many hurdles such as nutrient deficiencies, seedling diseases like Pythium and Stewart’s bacterial blight, slugs and insects like black cutworms. Adequate stand establishment is crucial for a good crop.

• At V3-V4 stage, make sure that weeds are in control. Apply post-emergence herbicides, if necessary. Even small weeds can affect yield.

• At V6-V8 stage, be sure to side-dress with nitrogen before the plants are too tall, if you are going to apply additional nitrogen. Check for deficiency of nutrients like sulfur, magnesium, zinc and other micronutrients.

• Pollination is the next most critical stage. Make sure that insects like Japanese beetles, western corn rootworm beetles are not clipping the silks. Use insecticides if needed to control these pests.… Continue reading

The fast growth stage of most of the corn is kicking in. This is the time when you can almost watch the corn plants grow. It is now starting to grow rapidly from puny little seedlings to the juvenile stage and become adults. Corn plants are ready to hit the grand growth stage.

At V7 stage, the corn plant is already deciding how many rows of kernels it can put on. Row numbers are always in pairs and primarily controlled by the hybrid genetics but environmental factors such as population, water and nutrient availability, heat and drought can influence it. Depending on the conditions, a couple of rows may be added or subtracted from the genetic potential of the hybrid.

• During V8-V9, potential ear shoots start to develop at every above ground node except the upper six to eight nodes. Only the upper one or two ear shoots eventually form the ears.… Continue reading

As the soybeans respond to the warmer temperatures and sunshine around the state, it is time to assess the stands to make sure they are setting things up for success this fall.

‘Most of the soybeans in Ohio are emerged and growing very fast. Now is the time for growers to access the quality and plant populations of their fields,” said Jeff Rectenwald, Asgrow DEKALB agronomist. “This weekend there has been some hail and growers will be in fields checking plant populations.”

Ohio State University and other university research from throughout the Midwest research found that base soybean populations as low as 100,000 can still produce solid yields. To get a stand count, Rectenwald suggests making a hula hoop out of three-eighths inch EVA tubing connected with a brass nipple connector. The hoop diameter should be 28.26 inches to help calculate 1/10,000^th of an acre. The hoop should be thrown out in the field and the plants inside it should be counted and multiplied by 10,000.… Continue reading