Fertilization and protection may increase health and yields in sunflower cropsWritten by Natasha Wheeler
South Dakota farmers Brian and Darren Hefty believe that properly feeding a sunflower crop, as well as protecting it from weeds, insects and diseases, will improve yields dramatically.
“Much like soybeans, sunflowers are very misunderstood when it comes to fertility,” remarks Darren.
Comparing two farms nearly 100 miles apart, he acknowledges the differences in growing conditions yet remarks on the significant crop improvements in a fertilized field.
“The first farm had a very specific fertility program for sunflowers. The stalks were big and mostly disease free. They stood very well until harvest and had big heads on the sunflowers,” Darren describes.
In the second field, the farmer’s philosophy is that sunflowers are a scavenger crop, and his plants had thinner stalks, lower quality stands and more disease.
“When we looked at a plant tissue analysis, we saw a lot of deficiencies. It was amazing to me what a difference there was in fertility from one farm to the next and what a difference that made in production,” he states.
The field with a special fertility program yielded nearly twice the crop as the unfertilized field.
Brian notes that there are three key nutrients to think about when growing sunflowers.
“If we’ve had lodging problems in any crop, it’s probably a potassium issue. It could also be manganese or copper. Those nutrients are all important if we’re looking at sunflowers,” he says.
Protecting the crop
Various diseases may also occur in sunflower crops, and Darren notes that many successful farmers use fungicides, with at least one application, if not two, per year.
“We’re protecting against white mold, powdery mildew and other diseases that can be very problematic in sunflowers,” he explains.
Insects can also pose a threat to sunflower crops, and there are a number of critical stages where bug pressure can become a problem, according to Darren.
“It’s important that we are out scouting on a timely basis. The best sunflower producers in the country are out at least weekly, looking in their fields with sweep nets, identifying which bugs are out there and spraying with appropriate products,” he states.
Brian adds, “The good news is, the appropriate products are very inexpensive. If we have a seed that’s protected from bugs and we spray foliar once or twice for bugs, we’re generally in pretty good shape, and we haven’t even invested $10 an acre.”
When it comes to preventing weeds, Brian and Darren highly recommend using pre-emergence strategies.
“We have two options. We have yellow, and we have PPO. We want to make sure we are using them both,” Brian remarks. “The problem is, sunflowers don’t give us very good crop canopy later on, and we don’t have any good foliar options for weeds.”
The combination of herbicides helps to deter small-seeded broadleaves that cause weed problems in sunflower crops, and they can be followed with a post-emergence grass killer later in the season.
“It’s fairly inexpensive if we need rescue options for grass, but we don’t have any good rescue options for broadleaves,” he says.
Brian also suggests giving management changes a few years to yield results as the potential benefits for the crop increase after a few seasons of providing protection and fertilization.
“There are many things we can do if we want to improve tonnage on our farms,” he remarks.
Using soil samples to determine nutrient levels can inform field input decisionsWritten by Natasha Wheeler
Generally, soils in Wyoming feature a lack of development, an expected find in dry environments. There is often poor drainage, but because low precipitation levels correlate with lower incidences of leaching, soils are often relatively fertile, with the exception of nitrogen.
“High calcium carbonate contents tend to flocculate soil particles and create good structure and drainage, but it tends to tie up a lot of phosphorous,” explains Jay Norton, University of Wyoming Extension soil fertility specialist.
Low levels of organic matter are also common in Wyoming soils, which is natural for the arid environment.
“We can’t say that’s a problem, but repeated irrigation and tillage tend to drive it even lower, and we lose the benefits of organic matter, which hold soil particles together, creating good soil structure, increased water holding capacity and nutrient cycling,” he describes.
One benefit of low organic matter in the soil is increased nutrient access for growing plants, although Norton notes that increased organic matter can improve overall soil health.
Using various soil tests, nutrient levels can be estimated in growing areas to help determine which fertilizers have the most beneficial impact.
“If we have an area we want to sample, how many cores do we take to put in our bucket?” Norton asks.
One core sample usually won’t account for high levels of variability in a field, but taking hundreds of samples requires a lot of time and money.
“Fifteen to 20 soil samples from one area is where we really start to see the benefit, although it depends on the variability of the field,” he comments.
Those 15 to 20 samples are combined in a composite sample to send off to the lab.
A number of different methods can be used to decide where soil for each composite sample comes from.
“The traditional method is by soil map and topography. We use these soil survey maps to delineate and divide the area into fields that have been managed differently, had different crops, different soil nutrient management practices, old feedlots or other things we know will affect changes,” describes Norton.
For each segregated area, 15 to 20 samples are taken for the composite test.
This method may or may not be accurate, depending on the area, as it assumes that the chosen areas have more variability than the variability seen within each area alone. Long-term management or natural geological features may affect the site and, therefore, the results of the testing.
Grids and zones
“Grid sampling is the other extreme. We lay a grid out on the whole field, and those 15 to 20 samples come from either each intersection of the grid or from within each grid cell,” he explains.
This particular method can be very expensive, so many producers use zone sampling, which combines ideas from both a traditional method and the grid system.
“Zone sampling tries to take advantage of all the tools we have available now. First, we develop zones on real information that we have, then we look at the yields and soil fertility to adapt the zones,” he continues.
Once results come back from the lab, the goal is to adjust inputs to match the needs of the crops, so despite the method, producers should try to gather soil that provides a representative overview of the area.
Reviewing the difference between nutrients in the soil and those actually available to the plants also impacts how fertilizers are used in the field.
To illustrate an example, Norton explains, “Our soil tests often come out high or very high for potassium, but we’ll still use potassium starter fertilizer because of our geology. Early in the season when it’s cold, the plants are very small, and they haven’t exploited the root zone. Starter fertilizer near the seed can give them a little bump, and the plants will actually respond, even if there is adequate potassium in the soil.”
Norton also reminds producers that soil science can be complicated, and nutrient levels can change throughout the season.
“Nitrogen is very dynamic,” he mentions. “Plant-available nitrogen is like a wildcard.”
One method Norton suggests is applying half of a recommended fertilizer prescription pre-planting to evaluate how the plants respond as they start to come up. Once they begin to grow, the second half of the fertilizer can be adjusted accordingly before application.
Plant tissue tests, soil sampling, remote sensing and stock irrigation tests can all be used to help determine the nutrient levels in a field and how plants respond to those nutrients.
“It’s difficult to know exactly how we should sample. It mainly depends on how much money we have,” he says.
Jay Norton spoke in Worland on Feb. 19 at WESTI Ag Days.
Products enhance soil activities, growthWritten by Saige Albert
“I believe that agriculture is the backbone of our country, and I’m a huge proponent of sustainable agriculture,” says Jackson.
Biologically based products
As a result, Jackson developed three biological products they now manufacture and distribute. The products are Bio-Stimulant, Harvest Energy and Fulvic Electrolyte.
Bio-Stimulant, a product that utilizes enzymes produced by soil microorganisms, promotes the growth of aerobic, or oxygen producing, species.
“We don’t have any live microorganisms in the product,” Jackson notes. “Instead, we have a series of fermentation processes that the product goes through, and we harvest the enzymes from the microorganisms.”
The soil microbes used are those aerobic, or oxygen producing, organisms, which Jackson notes is important. Oxygen in the soil is vital to encouraging the growth of new soil microbes and discouraging weed growth.
“Harvest Energy is a source of carbon,” explains Jackson. “There are a number of simple carbohydrates, like sugars, in the product. The other one-quarter of the product is electrolytes.”
Their third product, Fulvic Electrolyte, is a made from fossilized peat and is leeched using water, rather than a strong acid or strong base like many fulvic soil amendments.
“We wanted to use just water, so we use fossilized peat moss,” she says. “It is a mined material that is ground very fine. Then, we leach out the fulvic.”
Fulvic Electrolyte has iron, calcium and sulfur, along with trace amounts of manganese, zinc and tetra-cobalt.
“In situations where there might be a lot of crop residue, the fulvic helps to accelerate decomposition,” Jackson notes. “It also helps if the soil is exceptionally compacted or if it has a thick layer of thatch that has built up.”
ECS looks at soil quality to determine what customers need to improve their production and increase the efficiency of soil amendments.
“We help people learn to get the most benefit out of our products and any other soil amendments and fertilizers, including which ones are compatible and best suited for the soil,” explains Jackson.
By pulling soil samples at between four and six inches, she notes that they sample the nutrients most readily available to plants. The samples are sent to an independent laboratory, Midwest Labs, in Omaha, Neb. for testing.
“Based on the results we get back, we help customers consider the best options for nitrogen, potassium and phosphorus if they need it,” she adds. “If a soil sample indicates they don’t need any phosphorus or potassium, we encourage them to not put more on.”
Organisms in soil
“You get the most efficient use of products if you understand how they interact and what part the organisms in the soil play,” explains Jackson. “Soil microorganisms are a huge part of production, and without their involvement, production of anything would be less efficient and less healthy.”
Jackson says ECS emphasizes accentuating and working with soil organisms, particularly the aerobic species. The presence of aerobic microorganisms in soils promotes earthworm activity and the presence of arthropods increases, all of which help plant growth.
“It’s all geared toward the health of the soil. Healthy soil produces healthy crops, and healthy crops feed healthy animals and healthy humans,” says Jackson.
“Our bio-stimulants are all listed by the Organic Materials Review Institute (OMRI) as allowed for use in organic food production,” she adds. “We have a number of producers who are organic, but most are still using some commercial fertilizers, herbicides or pesticides.”
Producers who use the products have said they use less fertilizer and chemicals because of the improvements seen in fields.
“They can tell there are fewer weeds and less challenges from insects,” she explains. “Insects and weeds have a job in nature – they tell you where there might be excesses or deficiency in nutrients. Oftentimes that is indicative of an oxygen deficiency, and that’s where our products help a lot.
Currently, ECS has customers in Arizona, Colorado, Florida, Kansas, Nevada, New Mexico, New York, Oklahoma, Oregon, Utah, Washington, Wyoming and several Canadian provinces.
“I’m not anti-chemicals, but I like to see producers be as efficient as possible, whether that be with herbicides, pesticides and commercial fertilizers or with our products,” says Jackson, noting that her products can help producers get the most from their crops.
Crop consultant stresses balance in application of inputs for crop productionWritten by Natasha Wheeler
Deadwood, S.D. – “The biggest problem we have in agriculture is that we have 51 weeks to forget our mistakes,” remarked independent crop consultant Bryan Lutter at the Wyoming and South Dakota Joint Farmer and Rancher Conference in Deadwood, S.D. on Jan, 23.
Lutter has learned to trust his calendar more than his eyes when it comes to input application for his fields, because once signs are visible, it may already be too late to be effective.
“Personally, I have a stringent rule where I write down the number of days after planting and follow that very strongly. For example, on most of my crops, I apply product 21 days after planting. I don’t trust my eyes because it’s been 51 weeks since the last time I was looking at this particular situation,” he explained.
When Lutter works with clients to determine what inputs should be applied to a field, he stresses balance.
“I see people invest heavily in a certain part of their crop, and they neglect another part of their crop. If they satisfy the needs of a crop in one area but not in another area, it’s really hard on the pocketbook,” he stated.
Nitrogen levels are very important when evaluating the balance of nutrients in a field, and Lutter has spent a lot of time studying the nitrogen cycle. He is especially interested in mineralization, immobilization and denitrification.
“Immobilization and mineralization are opposites of each other. Those two things contribute to building organic matter, decomposing organic matter and tying up or releasing nitrogen,” he noted.
Lutter encouraged producers to spend some time learning about the terms, to better understand how they apply to crop management.
“Denitrification is a term that I want people to understand because it’s very common for people to believe they have leeching problems. We have very little leeching relative to the level of denitrification in America,” he said.
Denitrificaiton occurs when nitrogen is lost to gaseous forms such as nitric oxide or dinitrogen gas and occurs when the soil is saturated.
“It’s a real thing, and it’s one of the many aspects of the nitrogen cycle to learn,” he remarked.
One tool producers can use when they’re thinking about nitrogen application was created by North Dakota State University (NDSU) and can be found at ndsu.edu. Extension Soil Specialist Dave Franzen developed a number of calculators to evaluate the cost of nitrogen inputs to help producers with their management decisions.
“They have one for wheat and one for corn, as well. They haven’t finished the one for sunflowers, but it’s coming out soon,” Lutter noted.
Reminding producers that balancing inputs is important, he highlighted the difference between high- and low-input systems. Adding large amounts of fertilizer may not necessarily produce higher yields without also investing other protective measures such as pesticides or herbicides and visa versa.
“We don’t have to treat our crops like an ‘80s rock band treated its hair, spraying it all the time, but it’s okay if we do,” he stated. “I often have high-input and low-input fields on the same operation.”
One suggestion for producers is a weekly crop tissue sample from every acre, throughout the growing season.
“Not only do I believe that we should do a plant tissue test on every acre, every week, I also think we should use an incredible piece of lab equipment –our eyes,” Lutter remarked. “It’s a big deal to be able to visually see nutrient problems.”
For example, when he is assessing a field, Lutter looks not only for areas where crops are seemingly in poor condition, he also looks for weeds and places that look extra green.
“If we have little islands of green in a sea of yellow, it doesn’t matter if it’s the weeds or the crop, we probably have a fertility problem. I really try to look for that, even in little, tiny weeds, because it tells me if we lost some nitrogen,” he stated.
If nitrogen deficiencies appear to be a problem, deep soil tests can help producers determine what further steps need to be taken, as low nitrogen levels in the soil can become very costly.
“I don’t think farmers are capable of avoiding wrecks. We’re going to have wrecks. I’m going to scout wrecks this year, but I don’t like taking them to harvest,” Lutter continued.
Whether soil nutrient problems are due to management issues or natural causes, taking out the whole crop and replanting could be more beneficial in the long run.
“It’s not worth fighting it. Sometimes we just have to whack it and start over,” he remarked. “The replant fields are almost always the highest yielding fields, for whatever reason. When we have a problem in a field, we want to find it early, not beat ourselves up, kill it and start over or fallow the field. There’s nothing wrong with that in some areas.”
Taking a wrecked crop to harvest invites more problems, according to Lutter, who says that it’s better to admit to the wreck and learn from mistakes.
Although the neighbors may be applying different inputs at different times, he reiterated that management should be an appropriate balance for a given field.
“At the end of the year, we can look back and decide what strategies worked best,” he said.
UW soil fertility specialist gives economic advice on fertility programs for cropland
“With fertilizer economics, you have to answer whether you can afford to fertilize, or afford not to fertilize,” says UW Soil Fertility Specialist Jay Norton.
“A lot of money is wasted on over-fertilizing, and there are some basic concepts producers should consider before investing in an expensive fertilizer program,” he continues.
Norton lists soil tests as a first step to make in deciding on a fertilizer program.
“Soil test results should be where every farmer starts, and the basis of economic decisions in regard to fertilizer. Many fertilizer companies will do the test for you, and then apply what you need. But, there’s an inherit conflict of interest in that. They may have the best of intentions, but its safer to send a sample to an independent lab, where there is no value attached to the sample for that lab,” explains Norton.
The law of the most limiting factor is another area Norton suggests producers look at prior to entering their fields.
“The most limiting factor will always control the yield. It can be nitrogen, phosphorus and potassium (NPK) fertilizers, soil nutrients, water or any number of other things, and yield won’t improve until you address that limiting factor. If it’s not NPK, regardless of how much fertilizer you apply, you won’t see improvement,” notes Norton.
“Fixing one problem often reveals another, and soil and climate factors can also have a large influence. Many times the worst soils don’t need fertilizers because that’s not their limiting factor,” continues Norton. “Sometimes it’s NPK, but sometimes it’s not, and it’s important to consider all potential limiting factors.”
He continues, saying that reaching an economic optimum rate of fertilizer application is also important.
“In soils with low nutrient levels, where you get a big response, this economic optimum rate is pretty narrow and you need to get the soil nutrient levels up so that soil is producing near maximum yield. Even if fertilizer is expensive that year, you’ll get a good response for it, and chances are you will see more economic benefit from applying.
“In soils with a higher residual nutrient supply, you get less response from applying fertilizer, or less bang for your buck. So, economic optimum depends more on the prices of crops and prices of fertilizer, and results in a wider range that will be economically optimal.
“If you’re spending part of your fertilizer budget on one nutrient you know is deficient, you want to spent most of those dollars on the areas of the farm where you will get the most response. Spend most on those areas that are less responsive, and some on the areas that are more responsive,” explains Norton.
He also suggests adding some of each nutrient (NPK) in short supply to make use of positive interactions
“If you’re allocating funds between two or more nutrients, keep in mind that nutrients interact, and you should spend some money on each nutrient your soil tests suggests is in short supply. In Wyoming soils, P and K are typically limiting, and they interact with each other,” says Norton.
He adds that his work and literature says N is N, and P is P, and that each nutrient should be purchased at the cheapest price per unit, then applied appropriately.
“There are quite a few slow-release, polymer-coated urease inhibitors, or liquid slow release forms of N, on the market now. I’m asked if those are worth it, and our work on N products suggests that it’s not worth it, and to stick with whatever is cheapest, and apply it correctly,” continues Norton.
For those producers who would like to see the impacts that variables in fertilizer costs and applications can have, Norton recommends visiting landresources.montana.edu/soilfertility.
“You can change the cost of fertilizer, play with the residual soil N, and look at impacts of different crop prices. Montana State has done a good job on the website,” he explains.
“The take-home is to use test results to cut back any nutrient that’s in excess, and save money that way, and to apply fertilizer where it will generate the most return, and to use nutrients in combination to make use of positive interactions,” concludes Norton.