Skip to main content


Cover crops: Are they a real fix for water quality?

The use of cover crops has been growing over the past decade or so. But, do the benefits to the landscape from using covers in a cash-crop system actually outweigh the risks of changing practices and modifying operations? Cover crops need to pay dividends to both the individual grower and the landscape as a whole. The in-field advantages are much better known and documented than the effects on water quality and how it moves through the agricultural landscape. These landscape-level effects are critical in telling the story of mod­ern agriculture and how we are able to maintain top production while making positive steps in reducing the amount of agricultural inputs to surface waters.

To be successful in this quest, cover crops should decrease total water volume, suspended solids or soil leaving the field, and total phosphorus (P) and/or nitrates (N). The first two of these need to be measured, but we can make some educated assumptions when it comes to total water volume and soil loss. Cover crops increase surface cover and keep growing roots in the soil longer than cash crops alone. These additions will absolutely over time decrease soil loss and increase infiltration. But to what extent? Similarly, it’s reason­able to assume that the extra living plant uptake should reduce loss of N and P, but again, it is important to prove the extent to which the loss is mitigated.

For agriculture to remain “busi­ness as usual,” it’s critical to prove that cover crops can reduce losses of these pollutants. We need a success story to tell, and integrating cover crops can be a big one.

Recently, the Missouri Soybean Association and Missouri Corn Growers Association began a study that put water samplers on fields that were farmed using different practices. The samplers collect wa­ter any time there’s a runoff event. They track and measure total water volume, soil loss in suspended solids, N and P. For this study, these organizations used grant funding from EPA’s Clean Water Act Section 319 program, which specifically focuses on nonpoint sources of water pollution, such as agricultural runoff and soil erosion.

The information gathered from this research provides great insight about when losses are happening and what works to reduce total losses.

First, historical practices of grassed waterways and terraces seem to be working really well in re­ducing nutrient and sediment run­off. This is great news and proves the effectiveness of these practices that we’ve used for decades. Even when changing overall manage­ment to no-till or to include cover crops, it’s important to keep these structural practices in mind. When needed, nothing does a better job at stopping soil or nutrient loss than a good grass sod waterway.

Second, cover crops seem to be doing an overall good job at continuing to reduce nutrient and soil losses, especially in the spring. The large, intense rain events that come with spring not only hamper fieldwork, but they are also major contributors of those losses. Having a cover crop in place during these events can help. This also brings to mind some of the nutrient applica­tions made that time of year. Those nutrients can be especially vulner­able to losses and show up in the runoff. Minimize this risk by not applying right before large rainfalls, or move those surface applications to other times of the year when pre­cipitation is typically less intensive.

While it’s impossible to say that cover crops can reduce nutrient losses every time, it’s reasonable to say there are clear benefits. That conclusion is based on actual water sample data along with visual observations of field-level benefits. With the floods of 2019 fresh in our minds, the number of large rain events seem to be happening more often. For reasons both on and off the farm, cover crops are something to consider in row-crop agriculture.

For information about cover crop recommendations and how your cropping system can benefit, call me at 573-876-5246, email This email address is being protected from spambots. You need JavaScript enabled to view it. or con­tact your local MFA Agronomy team member.

  • Created on .
  • Hits: 1902

Keep calm and hang on: Still time to plant

For years, growers have been told the earliest-planted crop is the best crop. Dataset after dataset have been presented by university after university to back up this informa­tion. Couple this data with the “get ’er done” attitude typical of farmers, especially in the spring, and you get a mindset focused on one thing: getting a crop in as early as possible.

There is one fatal flaw in this mindset—early is not always better.

To say early planting has no advantages is not true either. An increased likelihood of flowering during milder weather, avoidance of certain pests and the possibility of an earlier harvest are all benefits of early planting. However, all those factors combined will not outweigh the two most important criteria for raising a top crop: soil conditions at planting and seed placement.

The simple fact is corn’s yield potential can still be quite high when planted into June. We witnessed this last year. There were several exam­ples of corn planted after June 1 nearly doubling yields of corn plant­ed into subpar conditions in April and May. So much is determined by a corn plant’s early life. Cold, wet soils cause inconsistent emergence and development, which leads to competition against other corn plants and greater vulnerability to disease. Small corn plants also have a much harder time metabolizing herbicides at this point.

Perhaps the biggest drawback of planting in wet conditions is what the planter actually does to the seed bed. Sidewall compaction was a very common issue encountered in 2019, caused by planters smearing and compacting the sides of the seed trench as it moved through wet soils. This can cause emergence issues due to poor seed-to-soil con­tact, but often the damage goes un­noticed until some type of stress is introduced. Root growth is limited, leading to mohawk or hatchet roots. Nutrient deficiencies or drought stresses are more evident in these fields much later in the growing season when planting conditions are all but forgotten. Often these issues get blamed on poor fertility or drought or other things, but it was very common for stressed fields in 2019 to show evidence of poor planting conditions. For example, when you can see trenches follow­ing the corn rows at planting, it was likely too wet, and hindered root growth is the likely result.

It’s also important to make sure seed placement is correct. Of course, much of this is aided by proper calibration and monitoring of the planter’s performance. Set­ting depth and down pressure are important as are making sure seed tube meters and all moving parts are doing their jobs in singulation.

However, among all the things we can control, speed is the most critical. Urgency bordering on im­patience becomes the enemy. Main­taining planting speed of 4.5 mph does as much for seed placement as any other practice. Sure we have “high-speed” planters, after-market “speed” tubes, and meters that can singulate at remarkable accuracy at high speeds, but singulation is a small part of seed placement. Consistent depth and placement in the seed trench are more important than singulation. Varying depth and placement cause not only geograph­ic inconsistency but also temporal inconsistency, which relates to un­even emergence and development.

The goal of planting should be to get all plants up within 12 hours of each other so they are competing on an equal playing field. The late emergers are like the runt pigs of a litter that take resources from the healthy pigs without gaining at a profitable rate themselves. High-speed planters can provide geo­graphic spacing consistencies, but even the best down-force systems struggle to compensate for row unit bounce when planting at high speeds. This causes higher inconsis­tencies in emergence.

With today’s equipment, most growers admit that they can finish their planting in less than a week. Moving from 4.5 mph to 6 mph means they can finish in roughly five and a half days instead of seven. How much yield loss is that one and a half days worth?

Though the advantages of early planting are real, they are also misleading. Yes, we want to take advantage of planting windows, but not at the cost of planting into cold or wet soils. If you drive a couple of miles per hour faster, are you accomplishing more? Maybe. But remember your goal—to raise yields. How do you achieve that goal? By giving your crop the best start from the beginning.

  • Created on .
  • Hits: 2206

'Bee'ing good stewards and applicators

The future use and availability of crop protection products, plant food and other agricultural inputs de­pend on good stewardship. Apply­ing them properly and wisely casts a positive light on agriculture and our ability to be environmentally responsible, which includes protect­ing pollinating insects such as bees, butterflies and moths. Whether you’re applying a product yourself or relying on a custom applicator, adhering to the same principles of stewardship is important.

Avoid off-target movement

The dangers of physical drift and herbicide volatility are well docu­mented when it comes to damaging a neighboring crop. However, these factors affect protection of polli­nator habitats and natural areas as well. When spraying an insecticide, there are a couple of things to keep in mind. Many habitats adjoining crop fields play an important role in maintaining the species diversity of pollinators and flowering plants. These “micro” habitats of less than an acre can contain staggering numbers of species. Keeping these habitats clear of physical drift is important for stewardship of these species. This applies to both herbi­cides and insecticides. Physical drift from insecticides can kill non-target insects such as pollinators, and drift from herbicides can kill flowering plants vital for pollinators.

Using precision equipment to make sure our field borders are spatially correct can help us avoid damaging these valuable adjoining habitats. If a waterway, buffer strip or pollinator plot is added near a crop field, be sure that boundary is edited to exclude those areas.

The time of day for an insecticide application is also an important consideration. If good control of the target pest can be achieved any time of day, making insecticide appli­cations during evening hours can miss most pollinator activity. This can greatly decrease the amount of non-target insects affected.

Follow the 4Rs

As a best practice for fertilizer appli­cation, MFA recommends following the 4Rs of nutrient management. Most of these practices deal directly with using current agriculture technologies to ensure nutrient applications stay out of surface and groundwater resources. Water quali­ty is something we need to contin­ually manage, but nutrient applica­tion effects can be minimized if we are good stewards.

Right Source: Use the type of fertilizer product that meets your crop needs. For example, if you are applying phosphorous on soybeans, choose a product that minimizes the amount of nitrogen applied. This ensures that extra N isn’t in the soil profile to be transported away from the field.

Right Rate: Soil testing is critical to being a good steward of nutri­ents. The better the soil data in hand, the better the recommenda­tion for product application can be. If there are high soil-test levels in a field due to past applications of livestock manure, there is little benefit to excessive amounts of fertilizer. In fact, there will likely only be negative environmental consequences to high applications in these areas. We have plenty of low-testing soils, and those are the areas where our maximum fertiliz­er investment will pay the highest dividends.

Right Time: Recent data from Missouri shows we are losing sig­nificant amounts of nutrients from our fields in the large runoff events that seem to occur every spring. This highlights the need to ensure nutrients are placed at opportune times. For nitrogen management, this means as close to plant uptake as possible and ideally in a split application format. Other nutri­ents may do better with a different strategy. Phosphorus, for example, may be best applied in the fall when runoff events aren’t as frequent. This allows maximum time for the P to bind to soil particles before the large spring precipitation events occur.

Right Place: Equipment mainte­nance is a must anytime precise ap­plications are necessary. Spreading equipment is no different. Pan and scale testing are critical to ensure the amount of product coming out of the truck is accurate in both pattern and quantity. If you own spreading equipment, be sure you are comfortable in all the calibration techniques necessary.

Overall, having more data in hand, taking a critical look at timing and using the right product in the right amounts can have a big impact on the landscape around us. Consider these factors as you move into crop year 2020. We not only farm in MFA trade territory, but we all live here, too.

  • Created on .
  • Hits: 1806

Extreme season proves modeling nitrogen pays

The 2019 growing season was certainly memorable, but it may be one that many would like to forget. Despite the stress it put on both growers and input suppliers, I feel there are many lessons to be learned in such an extreme year.

Last year, MFA used a new nitrogen-modeling tool called Nutri-Track N. It was certainly an interesting year to roll out this new technology. While we had been experimenting and demon­strating Nutri-Track N since 2016, last year was the first time we had such extreme potential for nitrogen loss. Previously, we had seen this recommendation tool help improve nitrogen use efficiency to 0.8 pound of nitrogen for every bushel of corn yield in many areas. That wasn’t possible in 2019, with excess rainfall pushing nitrogen below the root zone of the corn crop before it could be utilized.

During the past growing season, it took significantly more nitrogen to raise a bushel of corn than it did in previous years. For example, in one field where a check strip was left with no top-dress application, there was a 40-bushel per acre yield penalty. Nutri-Track N let us see the trend developing and respond appropriately, which is exactly what we hoped would happen. This recommendation system allows us to tailor nitrogen applications to the current weather pattern.

What makes the Nutri-Track N system different? It is based on years of university research that explains and models nitrogen’s life cycle in a field. It collects rainfall, tempera­ture, soil data and all the agronomic field practices we can provide, and then it estimates the amount of N that is available when the crop needs it most and models the need moving forward. Not only does it track what nitrogen is applied but also estimates what has been min­eralized from soil organic matter (OM). The more information we can feed to the program, the better the recommendation.

The best recs are achieved with the combination of grid sampling to provide OM levels and historic yield data to give us variable yield potential. By evaluating all these factors, Nutri-Track N shows the current status of the field and where it is expected to be at the end of the season—assuming typical weather patterns. The model is constantly improving by updating every night with new adjustments based on the previous day’s actual recorded weather.

In practice last year, this tech­nology worked as we had hoped. In mid-May, the MFA Precision Agronomy team started to send out alerts to our staff, warning that fields with unprotected fall nitrogen applications were at extreme risk of running short of this essential plant nutrient. By late May, we began to see more fields—even some that had received spring applications— that would benefit from topping off the nitrogen mid-season. The windows were tight to get that N applied, but it paid dividends when the combines rolled this past fall. In my estimation, nitrogen manage­ment was second only to stand es­tablishment in terms of importance to overall yields in 2019.

So, what did we learn from last year?

  • While we’ve always understood that using split applications with a planned top-dress application could improve nitrogen use efficiency, this past season, the system paid big yield dividends as well.
  • The later we can wait to make our overall total nitrogen invest­ment, the better off we are. The more information we have about our growing season, the better N rate decisions we can make.
  • Protecting your nitrogen with proven stabilizers pays. Any­thing we can do to maintain nitrogen in the ammonium form in the soil for a longer period is critical, not only to protect your investment but also keeping that nitrate out of surface waters.
  • There is no single right rate or application method for all of our nitrogen needs. It is a system with many variables. However, with the right tools we can con­tinue to improve efficiency and yields as we gain experience and knowledge.

I’m excited to see the results from those producers who used Nutri-Track N last year. While no two years are the same, I feel confi­dent that we are managing nitrogen better today and will continue to improve into the future.

  • Created on .
  • Hits: 3182

Gone to seed

Thanks to the sinister survival skills of weeds, seeds from as far back as 30, 40 or 50 years ago can be hanging out in the soil profile waiting for the right conditions to grow.

When weeds succeed, they are actively building a seed bank in your soil. One mature Palmer amaranth plant in a soybean field can add thousands of seeds to the soil. Other weeds aren’t as prolific, but each weed that goes to seed carries out its biological imperative to survive by depositing seed for the next generation.

In some ways, the weed seed bank in each field is a memory—not just from escapes but from cultural practices and field use history. Farmers of a certain age remember a different weed profile from the days of 30-inch rows or deeper tillage. The same can be said for major chang­es in herbicide chemistry.

Multiple factors dictate how long a weed seed will remain viable in the soil. Seed coat type is an obvious factor. Seeds with dura­ble coverings tend to stay viable longer wherever they land in the soil profile. But even long-lasting weed seeds are susceptible to microbial decay, being eaten by insects or birds, and germinating in fatal conditions.

Several years ago, Steven Fenni­more, a weed scientist at the Universi­ty of California, Davis, did a meta-study on weed seed banks. The data Fenni­more collected showed that most weed seed banks have multiple species but that a few dominant ones make up 70% to 90% of viable seed in the soil. A sec­ond group of seeds, those not adapted to survive in the current cropping system, make up 10% to 20%, with the balance being newly introduced weed species and seed from previous crops. These percentages make sense in terms of what we call “weed shifts,” as dominant weed species change with tillage or herbicide practices.

Those figures assume there has been no significant physical movement of weed seed, of course. Growers who had land inundated with floodwaters in 2019 might experience a weed shift as flooded land returns to production.

“When soil moves, we can see more emergence of weeds like cockleburs, a seed that can remain viable in the soil for 30 to 40 years,” said Dr. Jason Weirich, vice president of sales and agronomy for MFA Incorpo­rated. “Where we see soil deposits from riverbanks or scouring of topsoil, we are going to see weeds in some fields that we haven’t seen in a while. That’s the nature of seeds that can remain dormant in the seed bank.”

The good news is that the seed banks are affected by efficient weed control. Iowa State weed scientist Bob Hartzler has done work to show that consistently clean fields reduce the number of weed seeds in the soil, making control easier to maintain. The same research offers a significant caveat: It only takes one management disaster to rebuild weed seed bank deposits.

Whether talking to research weed scientists or agronomy advisors, they all insist the best defense against future weeds is control.

“First and foremost, we’re thinking about yield this season,” said Weirich. “And right now, the overlapping-residual method is proving itself effective. A full rate of a pre-emerge herbicide applied at planting followed 20 to 30 days with a post-emerge application of another residual is effective weed control, and effective weed control is going to keep weed seed out of the bank.”

  • Created on .
  • Hits: 931