Vol. 1, No. 6 May 24, 2017
Don’t Compound Your Problems with Compaction
With the recent rains and soggy soils that we have been having this last week, compaction should be on everyone’s mind. The ever increasing size of tractors and equipment, compaction can become a problem that will limit a client’s yield potential. How big of a problem will be determined by what kind of soil compaction is causing the problem.
There are two types of compaction farmers must be aware of, topsoil compaction and subsoil compaction. Topsoil soil compaction is due to ground contact pressure only, whereas subsoil compaction is directly related to axle load.
Ground contact pressure is the pressure that is exerted by a tire or track on the soil surface, expressed in pounds per square inch (psi). Reducing contact pressures will cause less topsoil compaction. In completely flexible tires, surface contact pressure is similar to tire pressure. With most farm tires, surface contact pressure is about 1 to 2 psi higher than tire pressure due to stiffness in the tire. The best way to determine contact pressure is to calculate the load in pounds per wheel and divide it by the area of the tire that touches the soil (in square inches). This will give you the average contact pressure under that tire in psi. Research shows yields can be reduced by as much as 10% due to soil compaction in the top soil. This compaction can be easily remedied with tillage and the natural freeze and thaw cycle.
Axle load is the total load supported by one axle, usually expressed in tons or pounds. Farm equipment with high axle loads will cause deep compaction. Deep subsoil compaction can only partially be alleviated with subsoilers, and at considerable cost. Freezing/thawing and drying/wetting cycles have been shown not to improve soil compaction at this depth. Research shows yields can be reduced by up to 15% with this type of compaction and will last up to 12 years. This type of compaction should be avoided at all cost.
Soils that are near or at their water holding capacity will act like a hydraulic ram and will drastically increase the chances of both surface and subsoil compaction.
In conclusion, compaction no matter how slight can cause a yield reduction and should be avoided. Keeping loads in the field as light as possible and driving on travel lanes will help in the majority of cases. Driving on saturated soils can lead to long term damage and yield reduction. Clients should be encouraged to stay off and not to “mud” in crops. Once roots have been restricted, the client has restricted water and nutrient uptake into the plant.
Take Away Bullets:
Make sure clients have the proper tire pressure
Help clients calculate axle load
Try to encourage axle loads under 7 tons
Most important, stay off of saturated soils!
Vol. 1, No. 5 May 17, 2017
Is Corn Emergence Corkscrewed this Year?
The most important pass a farmer can make in his field is the planting pass. With the ExactEmerge planters we can achieve 99% singulation, which also provides much-needed uniform spacing at emergence.
Successful emergence only starts with the planting pass, there are many factors that have to occur. Seedling emergence happens as a result of elongation of the mesocotyl that pushes the tip or spike toward the soil surface. If everything goes correctly, the appearance of the spike at the surface of the soil will coincide with emergence of the first true leaf. If the mesocotyl’s elongation gets stopped or impeded, it may start growing into a corkscrew configuration. This could lead to a complete failure to emerge or the leaves could start emerging underground.
Cold soils or wide fluctuations in soil temperatures throughout the day during the emergence process can contribute in developing a corkscrewed mesocotyl. In the last week we have had air temperatures moving as low as 30 degree Fahrenheit during the early morning and as high as 70 degrees Fahrenheit in the late afternoon.
A hard or crusted surface soil layer can restrict the mesocotyl from emerging properly. This can be caused by several different factors. An excessive amount of rain can cause soil crusting at the surface. Wet soil conditions at planting can cause severe sidewall compaction plus press wheel compaction over the furrow.
Herbicides, acetochlor especially, can affect the mesocotyl root development if the seedling’s growth conditions are slowed due to weather or soil conditions. However when herbicide injury is suspected to be the culprit, cool soils and dense soil crusting are often also contributing factors, so is difficult to pin the blame completely on the herbicide injury.
In conclusion, the planter pass is the most important field pass the farmer can make. It can also be blamed for a few seedling issues that are out of the planter’s control. If you are questioned about a “crappy” corn stand, it’s not always an equipment issue. There can be other factors at play and maybe digging a few seedlings up will uncover the real problem.
Take Away Bullets:
Planters are not always to blame for poor emergence
Check air temperature 2 weeks after planting
Look for hard or crusted surface soil
Ask if and what herbicides have been applied
Most important, dig up the seed!
Vol. 1, No. 4 May 10, 2017
To Replant, or Not to Replant: That is the Question
Should I replant my soybean crop and risk a late planting date or live with my emerged soybean population and risk a reduced yield? This question is brought to my attention every spring. Reduction in emerged soybean population can be a result of inaccurate planter adjustment, planting too fast, soil crusting, soil moisture extremes, pesticide drift, insects, or disease pathogens.
The first and most important step is to accurately determine the emerged soybean population. The person scouting the field should wait several days after emergence to make sure all the viable soybean seeds have emerged. Pick multiple sample areas at random across the entire field. There should be enough sample areas to give a good representation of the whole field. There are two common methods for estimating plant populations: counting plants in a row and using the hula hoop method. No matter which method you use, be sure to count only live plants. If specific field locations are a concern, separately determine the stand in those areas.
Once you know the living soybean population, you can make an educated decision to replant. Most tables show less than a 10% reduction in yield down to a population of 60,000 plants/ac. University data indicates that there is no yield advantage to filling in a stand of 66,000 or greater plants per acre. That’s because the second planting yield potential is lower due to the later planting date and competition from the original planting. The second planting can further damage the original thin stand by up taking nutrients and water. A soybean plant that will not yield grain becomes a weed that the farmer can’t kill.
If a client decides to keep the lower population, there are a few more management options that needs to be considered. Weeds, the client needs to be aware of the chance of higher weed pressure due to a greater percentage of the ground not being covered by soybeans. An additional spray pass of herbicide will be needed, since the soybean canopy will take longer to close. Foliar fertilizer, adding a foliar fertilizer to the additional herbicide pass will help jump start the vegetative growth of the soybeans and decrease the time to canopy.
In conclusion, when faced with a less-than-desirable soybean stand farmers have a very big decision to make. We can reduce the stress our clients feel by providing reliable information so the client can make an educated decision in a timely manner.
Take Away Bullets:
Accurately determine the emerged population.
Decide if the field needs to be replanted.
Make the proper management decisions to insure maximum yield.
AgDNA can be a very good source to make an educated decision.
Vol. 1, No. 3 May 03, 2017
Nitrogen, It’s What’s for Dinner
There has been a long debate on timing of nitrogen application. Purdue has shared a 3 year study from the Penny Purdue Farm around Wanatah, IN. The results are surprising to some not familiar with preplant nitrogen application. Dr. James Camberato applied the corn crops total nitrogen needs before planting and compared the yield to a split application of 40 units preplant and the remainder at side dress (V4). The results were statistically no different to a slight advantage for the total preplant application. Dr. Camberato suggest two reasons for his results. First, nitrogen is taken up into the plant thru mass flow and usually in the spring there is plenty of soil water to bring the nitrogen into the plant, whereas, late side dress can coincide with dry weather. Secondly, when nitrogen is applied during preplant the crop will have nitrogen available as soon as the seed hits the ground.
John Deere and Greenmark will always recommend to comply with the 4R principles of right fertilizer source, right rate, right time, and right place. Dr. Camberato’s study is just one of many that is worth looking into and replicating.
How many units of nitrogen should I apply? This question is asked every season. The answer is not as straight forward as it sounds. As an agronomist, I look at a soil test to see what kind of soil or more specifically how much cation exchange capacity (CEC) and organic matter does the soil have on that particular farm ground. In general, the higher the CEC the more potential for higher yields. Likewise, a high organic matter soil such as muck or black sand, will not need as much commercial nitrogen added to the soil as a low organic matter soil.
In conclusion, while split applying nitrogen will have the least amount of loss, there seems to be no yield difference between preplant nitrogen application and sidedress application in recent studies. Late nitrogen application with the use of Y-drops have shown some promise of yield increase, especially in years of heavy rain pressure due to the movement of nitrate (NO31-) out of the root zone. The use of a nitrate inhibitor in any nitrogen application will greatly decrease the chances of nitrogen loss due to leaching or denitrification. The lower the organic matter that a soil has, the more commercial nitrogen will need to be added to achieve your full potential yield.
Vol. 1, No. 2 April 26, 2017
Micronutrients Not Fancy but Essential
As the title suggests micronutrient applications are not the most widely talked about in the agriculture industry. They are not applied or sold by the ton, you may not even know your crop is deficient. The term we in the industry like to bat around is “Hidden Hunger”. Which means you may be raising a 190bu/ac corn crop, but if you position certain micronutrients in the root zone you may increase your yield to 210bu/ac. The two micronutrients that have the greatest effect on corn production are zinc and sulfur.
Sulfur deficiency is becoming more prevalent. We have been seeing a documented reduction in sulfur dioxide in the atmosphere for the last 30 years. This is mainly due to power plants and automobiles removing sulfur from their exhaust. Corn grains contain .5 pounds of sulfur for every 10bu of grains. With the trend line corn yield ever increasing, we are taking more sulfur out of the root zone than what is being replaced naturally. Your corn crop will pick up sulfur as Sulfate which has a double negative charge (SO42−) making sulfate very mobile in the soil, a kin to nitrate (NO31-). Since sulfate can be leached out of the root zone very quickly, the application must be timely and be correctly placed. This is why putting sulfur in with your 2x2 or popup starter can not only help with sulfur deficiency, it will also reduce the pH in the root zone allowing more micronutrient to become more available.
Zinc, the granddaddy of all micronutrients, is deficient in a corn cropping system more than any other micronutrient. Zinc is an important component in the production of multiple enzymes that are responsible for metabolic reactions in the corn plant, such as photosynthesis and DNA transcription. Most zinc in the soil is unavailable to the corn crop. Plants can only take zinc up that is dissolved in the soil solution, absorbed to the surface clay particles, or absorbed by and chelated with organic molecules in the soil organic matter. Cool wet conditions may result in less zinc in an available form. More and more farmers are planting into cool wet soils, placing a concentrated band of high quality zinc in with your starter will solve early zinc deficiency in your corn crop.
John Deere can provide a very efficient way of delivering these nutrients through our planters. Most studies show placing P, K, and micros in the seed furrow and nitrogen in a 2x2 application will be the biggest return on the investment.
Vol.1, No.1 April 19, 2017
As winter losses its icy grip, spring is fast approaching and the burndown season will be here if not already started on some of our sandier fields. The warm wet weather earlier in the spring have the winter annual weeds such as chick weed and purple dead nettle, taking over fields in a glorious fashion this year. This season of burndown will be the first time dicamba will be available to be sprayed late in the spring season in front of dicamba-resistant soybeans. As everyone has probably heard by now, there are federal labels for the use of 3 dicamba products, on dicamba-resistant (Xtend) soybeans. These products are Xtendimax (Monsanto), FeXapan (DuPont), and Engenia (BASF). These products are not a magic wand but a tool that have a whole list of regulations tied to its on-farm application. The main issue with a dicamba application is off target spray. This can derive from drift, volatilization, and tank contamination. Many clients still operate older sprayers. These sprayer may not contain an efficient process to apply the mandated 110ft buffer strips around the field or they may contain “blind spots” that can harbor dicamba and contaminate spray solutions. We should look at these inefficiencies as opportunities that can showcase the newest technology in sprayers. As the old saying goes, “Take your lemons and make lemonade”.