Micronutrients
A dose of microbes can let plants better withstand drought conditions by growing more leaves and roots and using less water, research shows.

 

March 31, 2016, Canada – WinField has expanded its Canadian product portfolio with the recent registration of Ascend SL plant growth regulator by the Canadian Food Inspection Agency.

Ascend SL is a soluble liquid plant growth regulator that contains a combination of cytokinin, gibberellic acid and indolebutyric acid that can fuel early plant germination and emergence.

 Research shows that Ascend SL plant growth regulator can increase yield potential when applied in-furrow for corn at planting, according to a company press release. Three years of field trial data from almost 200 locations showed that when combined with zinc 10% and a starter fertilizer (10-34-0), Ascend SL generated an average corn yield response of 4.8 bushels per acre more than in starter fertilizer applications without Ascend SL in trials across the United States.

In addition, Ascend SL plant growth regulator can be applied in combination with other seed treatments to help wheat crops with early season vigor, so they can withstand yield-limiting stresses throughout the growing season.

 

Crops require a number of nutrients in very small amounts called micronutrients. The most common micronutrients include boron (B), chlorine (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo) and zinc (Zn). There are at least five other elements that are needed by specific crops (that we won’t discuss in this article).

The term micronutrient refers to the relatively small quantity of a nutrient that is required for plant growth. It does not mean that these nutrients are less important to plants than other nutrients.

Table 1 below shows the total amounts of micronutrients taken up from the soil by high yielding wheat, barley and canola. Plant growth and development may be retarded if any one of these elements is lacking in the soil. Fortunately, we do not have widespread micronutrient deficiencies in Western Canada.

Sources of micronutrients in soils
Inorganic forms of micronutrients occur naturally in soil minerals. As minerals break down over time, micronutrients are gradually released in forms available to plants. Two sources of readily available micronutrients are nutrients that are adsorbed onto soil colloids (very small soil particles) and nutrients that are in the form of salts dissolved in the soil solution.

Organic matter is often an important source of most of the micronutrients. As soil organic matter decomposes, plant available micronutrients are slowly released into soil.

Soil sampling and testing
Soil testing can be helpful as an initial screening to determine if any of your fields are potentially low or marginal in a micronutrient. Have representative 0 to 6 and 6 to 12 inch depth soil samples analyzed for micronutrients. Most soil testing labs in Western Canada determine metal micronutrients Cu, Fe, Mn and Zn, using the diethylene triamine pentaacetic acid (DTPA) method. Boron is extracted using hot water and chloride is determined using water.

The general range levels used for determining when to add micronutrients to improve crop production are shown in Table 2, below. When a soil sample tests low in a micronutrient, a potential micronutrient deficiency may occur. A crop grown in field with a low micronutrient level in the 0 to 6 inch depth may not respond to a micronutrient fertilizer if adequate levels of the micronutrient occur in the 6 to 12 inch depth.

It is important for farmers and agronomists to recognize soil testing for micronutrients is not an exact science. The DTPA method for determining metal micronutrients works reasonably well for copper and zinc. The challenge is having reliable field research to determine the critical levels at which crops will economically respond to micronutrient fertilizers in the various soil and agro-ecological regions of Western Canada. Good research information is available for copper, limited information for zinc and very limited information is available for iron and manganese. Up to now, crop response to micronutrients across the Prairies has been minimal, making it difficult to accurately determine the critical soil test levels at which micronutrient responses may occur.

There isn’t a suitable soil test for molybdenum. The present soil tests used for boron and chloride are not very effective to predict crop response to these nutrients. For example, in a study in southern Alberta, about one-third of soils tested < 0.5 ppm for boron, which is often considered deficient. However, research trials conducted with winter wheat, spring wheat, barley, canola, pea, bean and corn at a number of sites over four years showed no positive responses to boron. From this and other work it is very clear the boron test and the critical levels used to recommend boron are not very reliable.

Soil factors affect micronutrient availability
Physical and chemical characteristics of soil can influence the availability and uptake of micronutrients:

  • Soils with < 2 per cent organic matter may have lower micronutrient availability; for example Gray soils.
  • Medium and fine textured loam, clay loam and clay soils are less likely to be low in plant available micronutrients.
  • Coarse textured sandy soils are more likely to be low in micronutrients.
  • Soils that have very high levels of organic matter > 30 per cent to a depth of 30 cm often have low micronutrient availability, particularly copper.
  • Soil temperature and moisture affect micronutrient availability. Cool, wet soils reduce the availability, rate and amount of micronutrients that may be taken up by crops. Cool soil temperatures can induce micronutrient deficiencies.
  • As soil pH increases up to 8.0 or higher, the availability of metal micronutrients may decrease.

Boron
Boron deficiencies have been suspected in canola and alfalfa grown on sandy-textured Gray soils. Research to specifically document crop response to added boron is limited. Normally, I would not recommend boron on an entire field based only on a low B soil test, due to the limitations of the test. If soil test B is < 0.5 ppm, I would suggest trying carefully laid out field scale test strips with sensitive crops like canola or alfalfa to determine if a soil B deficiency actually exists.

Application of borate or borax fertilizers can be broadcast for alfalfa, and either broadcast and incorporated or banded for canola. Boron containing fertilizers should not come into contact with the seed at planting. Soil application rates should not exceed 1.5 lb/ac on soils with a pH less than 6.5 to avoid boron toxicity problems. Foliar applications should not exceed 0.3 lb/ac to avoid toxicity problems. For all types of applications, extreme care must be taken to avoid toxicity problems.

Chlorine
The soil test for chlorine is very unreliable. Therefore, I normally would not recommend chloride on an entire field based only on a low Cl soil test.

Generally, crop requirements for chlorine are satisfied by the chlorine in the soil and received in rainfall. Rainwater on the Prairies typically contains 0.5 to 1 mg/l of Cl, which is more than sufficient to meet crop requirements. Chloride is also added to soil in potash fertilizer (KCl).

North Dakota research has shown that chloride added at rates higher than required to meet nutritional needs is associated with suppression of root and leaf diseases in some cereal crops. However, western Canadian research is very limited to demonstrate this benefit in Western Canada.

Copper
Research has clearly shown cereal crops will respond to added copper when soils tests are low. Wheat and barley grown on Black or Gray soils may benefit with copper application when the soil test for Cu is < 0.5 ppm. Wheat and barley response to copper on Brown and Dark Brown soils is uncommon and copper should only be applied to these soils when soil test Cu is < 0.3 ppm.

Cereal crops grown on soils with greater than 30 per cent organic matter to a depth of 30 cm often respond to copper fertilization, when soil test levels are < 2.5 ppm.

Generally, copper deficient mineral soils tend to be either sandy or light loam soils with levels of organic matter in the range of six to 10 per cent. Copper deficient soils are sometimes associated with soils with high levels of soil phosphorus or which have received heavy applications of manure.

Broadcast and incorporated rates of 3 to 8 lb/ac of copper in the form of copper sulphate or copper oxide are recommended for deficient mineral soils. On organic soils, broadcast and incorporated rates of 10 to 15 lb/ac are necessary. Soil application rates should be effective for five to 10 years. Chelated forms of copper are also effective in the year of application but the residual effects in Prairie soils is not well known.

The benefit of copper foliar application to cereal crops grown on mineral or organic soils is not as consistent but can be used when deficiency symptoms appear. Foliar applications are required annually and are most effective at the late tillering stage. If the deficiency is severe, two applications at mid-tillering and boot stage may be necessary. Foliar application rates of between 0.2 to 0.3 lb/ac are recommended.

Iron
Iron deficiencies have rarely been observed in field crops in Western Canada. Soybean is a relatively new crop to the Prairies and is particularly sensitive to low soil iron levels.

An iron soil test below 3.0 ppm is considered very low and at 3.0 to 5.0 ppm is considered low. These critical levels need western Canadian field research to be verified. Deficiency symptoms with soybean most commonly occur in cool, wet spring conditions. However, research in the U.S. has found the DTPA test is not well correlated to iron fertilizer response. U.S. research generally has found a foliar application of 0.15 lb/ac is recommended versus a soil application for soybean. Note that in the spring as the season warms up, soil iron tends to become more available to the crop and may grow out of the deficiency.

Manganese
Manganese deficiencies may occur on organic soils and high pH mineral soils. Deficiencies are rare but can potentially occur during cool, wet conditions in spring. Oats are more susceptible to a manganese deficiency than other cereal crops. Organic soils with a high pH are more likely to respond to manganese fertilizer.

Only limited information is available on manganese fertilization. As a rule, broadcast applications are less effective. For cereals, a seed placed treatment of manganese sulphate may be more effective. Foliar application can also be used if deficiency symptoms develop during the growing season.

Zinc
Zinc deficiencies tend to occur on soils that are calcareous, have a high pH, are sandy in texture and/or have relatively high soil phosphorus levels. Deficiencies tend to occur in spring when conditions are cool and wet. In southern Alberta, irrigated field beans have responded to applications of zinc particularly on sandy soils. Zinc deficiencies have been suspected in some irrigated cornfields in southern Alberta, but research trials have not confirmed this. Response to added zinc may occur on eroded or machine leveled soils or soils that have had large amounts of added phosphate fertilizer.

For soils that test low in zinc where a sensitive crop such as beans, corn or wheat is grown, a band application of 2 to 5 lb/ac of zinc sulphate or 0.5 to 1.0 lb/ac of a chelated zinc is suggested. When zinc deficiencies are suspected early in the growing season, a foliar application of 0.5 lb/ac of zinc sulphate can be used. On eroded soils, a 5 lb/ac broadcast incorporated application of zinc sulphate can be tried.

It is important to keep the need for micronutrient fertilizers in perspective. Many farmers have applied micronutrients in the hope of increasing crop yields even though there is little evidence to suggest a deficiency exists.

Farmers with fields testing very low or low in a micronutrient are encouraged to apply the nutrients in carefully laid out, replicated test strips. These strip treatments must be carefully marked out for comparison to adjacent control strips. Visual comparisons and yield measurements should be made to confirm if a yield benefit actually occurred.

There is no doubt soil micronutrient levels will gradually decline as cropping continues. As soils continue to be cropped, micronutrient deficiencies may become more common as available levels of some elements are depleted. Fortunately, most Prairie soils are currently well supplied with micronutrients. Soils and crops in Western Canada that require micronutrient fertilizers are the exception, not the rule. Care must be taken to keep the need for micronutrient fertilizers in perspective and not to promote them beyond their true significance.

TCWmidmarch micronutrient

 

With a wide variety of products for crop nutrition, seed and protection, farmers have more supplement and micronutrient choices than ever. Photo by John Dietz.

Cautious optimism is likely a good way to approach the new products section for any local ag retail outlet, according to veteran agronomist Norm Flore.

Flore has been involved with agriculture, fertilizers and research in Western Canada for 35 years. Currently, he provides agronomic services in retail outlets for Crop Production Services (CPS) in southern Alberta. CPS has a wide range of products for crop nutrition, seed and protection. The shelves are more packed than ever.

“There is a barrage of products that farmers are faced with right now, and they have a wide range of claims associated with them,” Flore says. “Our customers, often in conjunction with an agronomic advisor, have to sort through that, especially new products. There’s always been a lot of products out there, but the rate for new introductions seems to be increasing or spiking.”

He’s right. Before April 26, 2013, the federal Fertilizers Act Regulations contained quality and efficacy requirements for fertilizer and supplement products. The Canadian Food Inspection Agency (CFIA) enforced these regulations by conducting pre-market efficacy assessments, verification of performance or benefit claims and monitored for product quality in the market. It also required regionally based efficacy data.

It reviewed all labels being planned – and took up to three years doing it – to protect customers. If a label claimed a product could improve yield, the agronomist and all customers knew the label claim had hard scientific data.

Those CFIA practices were discontinued as of April 26, 2013. The CFIA process for registration takes the same amount of time today, but the scope is narrower.

In principle, according to the CFIA, this new flexibility supports innovation, reduces burden and expedites delivery to market for safe fertilizers and supplements.

Theresa White, a Monsanto Canada regulatory officer in Ottawa, offers this insight: “The registration-approved stamp means that the product has been assessed by CFIA for safety for human health and the environment and is safe when used according to the approved label information. 

“The CFIA also reviews product labels to verify that requisite information, such as guaranteed analysis, directions for use, company/manufacturer contact information, appropriate units of measurement, and mandatory cautionary statements, correctly appear and are clearly legible on the label.”

Each product registration is valid for three years, after which is must be re-registered. The categories and registration numbers on the CFIA website (www.inspection.gc.ca) can be summarized into four categories: farm fertilizer (50), fertilizer-pesticide (30), micronutrient (335) or supplement (392).

Recently, the number of registered supplements has been increasing: in April 2013 the number sat at 291; in September 2015 it increased to 366 with another jump to 392 in October 2015.

Registered micronutrients change, too. Twelve micronutrient registrations were issued in the first 10 months of 2015. The companies with most total registrations, as of October 2015, included: Nutri Ag Ltd. (31), Terralink Horticulture (31), Cameron Chemicals (21) and Winfield Solutions (19).

The big registration activity recently has been on the other side – registrations for supplements, that is. As of October 2015, the posted list shows 216 active supplement registrations predating 2014 and going back many years. However, 53 new registrations were issued in 2014. Another 74 were issued in the first 10 months of this year.

Buyer beware
For Flore, the issue comes down to data. If a new product has lots of local data, he probably will try it and encourage customers to try it. If it doesn’t have that, it’s time to be cautious.

“To go through the registration process now, you don’t have to show product efficacy at all. In a lot of cases, it’s simply claims being made for a product. There’s a lack of good hard scientific research to demonstrate the effectiveness of some products,” the senior agronomist says.

For new products, he tries to keep an open mind. He looks for the science behind the label claim, but allows for customer influence. If a grower is interested in something new, Flore eagerly coaches the grower to test the product in the local environment.  He believes newcomers to the market should have a fair trial.

“Yes, I tend to be skeptical on many of the products that are introduced especially if there are no claims on the label or a lack of performance results in the local area,” he says. “Still, I encourage customers to give it a try. I like being in the field with growers. I say, let’s try it in this environment where it has the best chance of working. I’ll monitor it. I’ll even do some crop yield and quality assessments to get a handle on whether a product is working.”

Product introduction time is a good time to ask if some product is available at no cost – select suppliers offer some product at no cost in exchange for some data on its performance.

A fair trial, Flore suggests, can be in proportion to a farmer’s confidence in the likely benefit from a new product. For example, he suggests, if there’s a 20 per cent chance of a benefit, try it on up to 20 per cent of a field or a crop.

“Talk to the reputable local agronomist and the input supplier to learn what they’ve seen and what they’ve heard, in the area, about the product or the type of product. We don’t have all the answers, so I encourage quality on-farm testing,” he says.

Or, after consulting a bit, perhaps buy the smallest jug or package available. In most cases, one container is enough to get a feel for the product performance.

“Work with an agronomist to help you select the right product, right field, the right crop, the right timing, the right application method to do things as well as possible. Then, use GPS technology and do 20 or 40 acres. You know exactly where it’s at and you can assess the yield,” he says.

“We can’t wait now for third-party research to cover off all these different products, it’s just not happening. There’s very little independent third-party research left out there, so it goes back to growers to do their own testing.”   

BioAg Alliance activity growing
Novozymes and Monsanto lead the registrant activity for micronutrients and inoculants. They account for 108 of the nearly 400 registered products in the CFIA list of supplements as of October 2015.

 

The two companies formed BioAg Alliance in February 2014 with a mandate to provide sustainable bioagricultural solutions. Many of the “me-too” new registrations for Monsanto reflect its new access to Novozymes technology.

The companies say the BioAg Alliance is meant to bring the capabilities of Novozymes in microbial discovery, development and production together with Monsanto capabilities in microbial discovery, advanced biology, field-testing and commercialization. The stated goal of the alliance is to help farmers meet the challenge of producing more with less in a sustainable way.

Monsanto BioAg is the commercial division of the BioAg Alliance. This year, Novozymes BioAg gained 13 registrations for QuickRoots in either wettable powder or a dry formulation, for soybeans, small grains, corn, canola, alfalfa or pulse crops.

Meanwhile, Monsanto BioAg broadened its product portfolio by registering 11 of the 13 QuickRoots products with Monsanto labels.

“To fully understand what this means, they are primarily Monsanto asking for the registration based on existing Novozymes BioAg product registration,” says Jon Treloar, a technical agronomist with Monsanto BioAg.  

Treloar says the BioAg alliance is data-driven. Monsanto BioAg is responsible for field-testing in Canada. It proves the efficacy of each claim by doing costly, time-consuming testing.

“This year, we had 150 small plot trials at 150 locations across Canada, and we had close to 200 field scale trials through the BioAdvantage Trials program.”

However, he adds, supplying the data to prove a label claim is voluntary. The CFIA efficacy requirement has been removed for nearly three years.

 

 

When we think of applying fertilizer, the nutrients that come to mind initially are the major nutrients nitrogen (N), phosphorus (P), potassium (K) and sulphur (S). However, there are 10 other mineral elements or nutrients needed by plants – most are micronutrients. In most agricultural soils, widespread shortages of micronutrients are uncommon, but when one or two of them are in short supply, crop growth can be severely restricted and crop yields depressed.

In the Northern Great Plains (NGP), it was only a couple of decades ago that micronutrient deficiency began to be considered a significant occurrence. Now, most areas readily accept that micronutrient deficiencies can occur. There are a number of reasons why this has happened. First, farm soils have been cropped longer, with most fields having a crop production history of over 100 years. Secondly, as higher yielding varieties and hybrids have been developed, crop yields and nutrient removal through harvest have continued to increase. Third, agronomic science has continued to improve soil and plant analysis techniques to better detect low availability of micronutrients. Lastly, education of field agronomists and crop advisers has increased the awareness and ability to look for, and diagnose, possible micronutrient deficiencies.

A micronutrient deficiency will not occur over a whole field, but will be present in irregularly shaped areas within a field. Patches are often severely affected, and these graduate into moderately affected areas, and finally transition into areas that do not exhibit or have any micronutrient deficiency. This is the result of natural spatial variability in soil characteristics that affect micronutrient availability. These characteristics include soil pH, texture, organic matter, cation exchange capacity, electrical conductivity and soil drainage.

Just because there are some areas of micronutrient deficiency doesn’t necessarily mean a whole field should receive a micronutrient application. For example, while field scouting with a farmer for the presence and severity of an insect pest so he could make a decision whether to apply an insecticide or not, he asked me to look at an area of canola that had poor growth. I was able to recognize boron (B) deficiency symptoms and took both soil and plant samples from the poor growth area, as well as from an adjacent area with better crop growth. The analyses confirmed my visual diagnosis of B deficiency, but I’ll admit his response at first was a bit disappointing. He said “I realize you did a great job, but it’s only five acres and there is no sense getting too excited for such a small portion of the field.” His response made sense after some thought, as the benefit of correcting the deficiency on such a small area didn’t justify the time and cost.

The patchiness of micronutrient deficient areas in a field and the difficulty of assessing the true extent of a micronutrient deficiency are challenging. I suggest we approach the challenge in much the same way crop advisers approach pest infestation assessments. First, confirm the suspected problem and assess the extent
of the field that is affected. Next, make an estimate of what the economic cost will be if nothing is done to correct the problem. Lastly, compare the cost of treating the problem with the value of the expected yield increase if treated with an in-crop foliar micronutrient. If there is sufficient net return from applying a micronutrient to the crop, go ahead with the application.

One last word of advice: even if an in-crop micronutrient application isn’t justified using this assessment procedure, it is useful to conduct further soil sampling on the field after harvest to more accurately assess the extent of a micronutrient deficiency. Further investigation may show more of the field may be moderately deficient, and a blanket application of a soil-applied micronutrient containing fertilizer may be a useful decision for longer-term crop production on the field.  

 


Dr. Thomas L. Jensen is Director, Northern Great Plains International Plant Nutrition Institute (IPNI). Reprinted with permission from IPNI Plant Nutrition Today, Fall 2014, No. 2.

 

A response to applied zinc rarely happens on Prairie soils. Zinc (Zn) deficiencies tend to occur on calcareous, high pH soils that have been machine leveled, are sandy in texture or have relatively high soil phosphorus (P) levels.

In Saskatchewan and Alberta, some of the earliest fields developed for irrigation were land levelled for flood irrigation, creating the potential for Zn deficiencies. While rare, Zn deficiency has been observed in irrigated alfalfa fields during stand establishment near Outlook, Sask.

“I thought Zn response would be a piece of cake on those land-levelled fields but I haven’t been able to prove that you can get a Zn response on those fields, except for a couple cases on newly established alfalfa stands,” says Gary Kruger, provincial irrigation agrologist with Saskatchewan Agriculture at Outlook, Sask.

Fields that were land levelled redistributed topsoil so that water could uniformly flow over the field. Kruger says this alteration could result in the soil being unable to supply sufficient zinc for crop growth. Crops such as beans, corn, flax, soybeans, alfalfa, barley, potatoes and wheat are more sensitive to a low supply of zinc from the soil and, as such, may benefit from zinc application.

Deficiency symptoms usually show up first in dry bean and lentil, and these crops may be responsive to added Zn. Very high rates of P may also induce Zn deficiency in flax.

Kruger first noticed a zinc response at a Miry Creek Irrigation District demonstration site at Cabri, Sask. in 2011, which was established to evaluate the nutrient requirements of a new alfalfa field to provide improved yield, stand longevity and competition with weeds (dandelion). The field had a poor history of production since it was developed in the 1970s. The clay soil had been in annual cereals for several years, and the field was divided into six strips testing the following fertilizer treatments: P alone, potassium (K) alone, P-K-Zn together, P-K together and control treatments. The project was sponsored by the Irrigation Crop
Diversification Corporation (ICDC).

The field was seeded to Stealth alfalfa on June 12, 2011, with a cover crop of Morgan oats sown at 35 lb/ac. The Stealth alfalfa was sown by splitting the seed in half and double seeding the field at 45 degrees to the direction the cover crop was sown. The alfalfa had excellent emergence and establishment in 2011.

A 0- to 6-inch soil sample was analyzed prior to fall fertilization 2010. A critical level of 3.0 ppm in coarse soils and 1.5 ppm in medium to fine soils has been established for dry bean production under irrigation in southern Alberta. This field tested at 1 ppm, rated as low by Midwest Laboratories. Fertilizer recommendations based on a target yield of 3 ton alfalfa/ac from this analysis was 40 lb P205, 9 lb sulphur (S), 1.8 lb Zn, 2.3 lb manganese (Mn) and 20 lb elemental S/ac. Phosphorus was applied to the field at about double the recommended rate suggested by the November 2010 soil analysis. (See Table 1.)

Kruger notes that phosphorus fertilization reduces Zn uptake in the alfalfa. Tissue testing at the early bud stage during the year of establishment showed that the Zn levels in the P alone and P-K treatments were lowered to marginal levels in the alfalfa tissue. He observed that during the year of establishment, the
alfalfa treatment that had the P-K-Zn fertilizer had a darker green colour. In addition, this treatment had a higher yield in the first cut compared to the other treatments, but that advantage disappeared in the second cut and the second year of harvests.

“The difference at the first cut may have been that the alfalfa roots weren’t exploring enough of the soil to obtain enough zinc for growth, but after it grew more later in the year and in the next year, the larger root system increased the plants’ ability to find zinc in the soil, so we didn’t see an advantage after the first cut,” says Kruger. (See Table 2.)

Kruger also observed a Zn deficiency in a research project initiated in 2013 and led by Sarah Sommerfeld, regional forage specialist with Saskatchewan Agriculture at Outlook. The project was set up to look at P, K and S fertilizer needs of a new alfalfa stand. During the year of establishment in 2013, a Zn deficiency was noticed.

“When they went to put down the fertilizer treatments in October 2013, they found symptoms consistent with Zn deficiencies, and a plant tissue analysis confirmed the deficiency,” says Kruger.

With the detection of the deficiency, a Zn treatment was added to the study. This project will carry on in 2014 with yield and forage quality analysis.

While these two examples provide an indication of the potential for Zn deficiencies, Kruger cautions that more research is needed to confirm if Zn deficiencies are more widespread than thought.

“One of the issues I see with southwest irrigation projects is the longevity and productivity of the alfalfa stands. My gut feeling is zinc may help alfalfa stands remain productive longer. I have also seen that protein content in alfalfa isn’t always up to snuff, and maybe zinc could help deal with that as well,” says Kruger.

Another factor that may be at play is that the land-levelled fields can have K deficiencies. Kruger says he has seen very good responses to K fertilizer on alfalfa. Because K stimulates root growth and root exploration of the soil, K fertilizer can help a plant overcome other nutrient deficiencies in fields with irregular fertility due to land leveling.

Until more is known about fertilizing alfalfa, Kruger recommends farmers balance their fertility program based on soil test recommendations. He says that if a field was land levelled, a Zn deficiency is likely for sensitive crops and may benefit from a Zn fertilizer application. Zn is easily blended or impregnated on fertilizer, which can be broadcast or banded.

“Zinc applied to soils attaches to soil particles and is agronomically effective for many years. I speculate that a three lb/ac application is enough to correct the problem perhaps for a farming career,” says Kruger. 

 

zinc nutrient

 

Field research on starter fertilizers for corn in Ontario continues to show that potassium deserves more respect as a crop nutrient.

May 25, 2012, Lexington, KY - Solving the problem of greenhouse gas emissions from agricultural soil and developing more nutritious food for young children were the two winning topics in this year’s Alltech Young Scientist Program, announced today at Alltech’s 28th Annual International Symposium. There was unprecedented interest in the competition this year, with close to 8,000 participants, representing the future generation of animal health scientists.

Five regional winners representing Asia, Latin America and North America came to Lexington, Ky. to present their research before a panel of international judges for the graduate grand prize of $10,000 and the undergraduate grand prize of $5,000.

This year’s graduate winner was Qian Wang from China, who is currently a PhD student at the University of California, Davis. Wang’s research work at UC Davis focused on preventing greenhouse gas emissions (nitrous oxide) from agricultural soil. She won with her paper titled “Effects of Inorganic Versus Organic Copper on Denitrification and Nitrous Oxide Reductase Activity in Soil.”

Gisele Greghi, from the Universidade Federal de Lavras, Brazil, was the winner of the undergraduate competition. Greghi’s research work focused on how to feed animals to reap health benefits in children. She won with her paper titled “Organic Selenium Combined with Vitamin E and Sunflower Oil in the Diet of Lactating Dairy Cows: Beneficial Effects of this Nutritional Approach for Animal Production and Human Health.”

“This year’s competition brought five outstanding students from around the globe to Lexington to compete. It was an exciting competition and the research papers presented all have the potential to result in significant improvements in animal and human health and welfare,” said Dr. Inge Russell, director of the Alltech Young Scientist Program and professor at Heriot-Watt University, Scotland.

“This year’s winners demonstrated yet again the importance of investing in education and the phenomenal innovation and originality that results from doing so,” said Suniti Mujumdar, Alltech’s manager of education initiatives. “It is more important now than ever before to recognize and harness the power of these young minds because it is here that solutions for the future will flourish.”

To participate in this program, students wrote a scientific paper that focused on an aspect of animal health and feed technology. The first phase of the program included a competition within each competing country, followed by a zone competition. The winners of each zone moved on to a regional phase and the regional winners competed in the global phase.

The Alltech Young Scientist Program is currently taking applicants for its 2013 competition. To enter, visit the website at www.alltechyoungscientist.com.

The Alltech 28th Annual International Symposium is hosting nearly 3,000 delegates from 72 countries in Lexington, Kentucky, May 20-23, 2012. Keep up with the latest happenings through live broadcasts on the Alltech Ag Network and blogs posts at www.alltech.com/blog. Join in the conversation on Twitter using the hash tag #agfuture. Photos, interviews and videos are available for download at www.alltech.com/press.

About Alltech

Founded by Dr. Pearse Lyons, Alltech is a global animal health and nutrition company with 32 years’ experience in developing natural products that are scientifically proven to enhance animal health and performance. With 2800 employees in 128 countries, the company has developed a strong regional presence in Europe, North America, Latin America, the Middle-East, Africa and Asia.  For further information, visit www.alltech.com. For media assets, visit www.alltech.com/press.

Soil testing is an important tool for developing fertilizer recommendations. However, soil testing has become more complicated as cropping systems and rotations have changed, and the use of legume crops and manure has increased. The best strategy is a combination of proper testing and recommendation tools along with grower knowledge, experience and the “best guess of soil moisture during the growing season.”

“Any type of soil testing should be regarded as providing an estimate of nutrient reserves,” says Dr. Don Flaten, professor, Department of Soil Science, University of Manitoba. “The nitrate N soil test has been developed over the last 50 years in particular to give prairie farmers a good estimate of immediately available N in the soil. It usually works reasonably well, but there are exceptions. One example of where the soil test may be unreliable is in the humid areas such as parts of British Columbia and most of central and eastern Canada, where there is a high risk of loss between the time nitrate N is measured and the crop takes up N.”

The nitrate N test provides information on what is immediately available in the soil, but does not have the capacity to predict gains or losses of N between the time those reserves are measured and the time the crop may be taking up N. “For example, large amounts of cereal residues can depress nitrate N reserves whereas large amounts of legume residues can increase nitrate N reserves,” explains Flaten. “There is also the risk of under-predicting the soil supply of N, particularly where manure has been applied, or legume residue, as these organic sources will release N during the growing season.”

Dr. Ross McKenzie, research scientist – agronomy with Alberta Agriculture and Rural Development in Lethbridge, notes that the soil nitrate N test worked very well, even up to the 1990s, and provided good relationships between soil test nitrate and crop response. However, recently this has become more of a challenge and is a result of more farmers switching from conventional tillage to direct seeding systems. This change in cropping practices has changed some of the nutrient cycling in the soils, and therefore, the correlation of the soil test nitrate N with crop response isn’t as good.

In a research project from 2006 to 2010, McKenzie compared 16 irrigated sites with 11 different crops at each site to develop new fertilizer response curves. “From soil sampling prior to seeding and at the end of the growing season, and check strip comparisons, the results showed that on average 80 lbs/acre of N were released during the growing season under irrigation,” says McKenzie. “Therefore we need to develop a way to measure not only the nitrate N, but how much the organic matter can potentially mineralize during the growing season.”

McKenzie still strongly encourages growers to soil test and use that information along with fertilizer recommendation tools and response curves to determine an economic fertilizer application rate. “These tools at least help growers get into the right ballpark and although they may put on a bit more fertilizer than is needed, the application rate is still based on logic,” says McKenzie. “We have initiated a new five-year study that will be conducted at nine dryland direct-seeded sites across Alberta to correlate soil nitrate to crop yield increase for wheat, barley and canola. Soil moisture is closely measured and will be included in crop response information. We will also be looking at N fertilizer types, application times and placement for each crop, and hope to develop improved N fertilizer response information as a result of the study.”

Dr. Rigas Karamanos, manager, agronomic solutions, for Viterra in Calgary also recommends that soil testing be viewed as a guideline, not an absolute science. “Weather is the great equalizer, and there are no perfect models for predicting the weather during the growing season. There are additional tools that can be used with soil testing such as recommendation engines for fertilizer applications; however, you still have to make gross assumptions about what soil moisture will be like over the course of the growing season.”

In many parts of Western Canada, the 2011 growing season was a challenge, and in some parts of southeastern Saskatchewan and southwestern Manitoba fall soil tests are showing huge levels of N. “In early November 2011, some samples were showing soil N levels of 200 lbs/acre in the soil,” says Karamanos. “Those high levels are real; however, most fertilizer recommendation tools have a maximum level where they quit recommending, so common sense has to take over. In this situation, a grower probably wouldn’t put on the usual 100 lbs or even 50 lbs, but 25 lbs/acre might be a good idea to get the crop growing. The caution is the conditions that generated that high level of N can reverse themselves and there can be a lot of
immobilization.”

Karamanos is finalizing a soil moisture conversion chart to help determine how much yield is stored in the soil. He has also developed a Virtual Soil Test that can assist with decisions. “Consider your crop rotations and the impact on soil N levels,” says Karamanos. “For example, previous research shows that legume stubble can contribute at least 40 lbs/acre of N, so soil test legume stubble in early spring, or as late as possible in the fall. With canola, hybrid canola varieties have a higher yield potential and tend to use higher levels of nutrients and water from the soil than open-pollinate varieties, depleting resources for the following crop.”

Researchers and industry recommend that, when making fertilizer management decisions, you start with a soil test; it’s still the best tool. Use all of the information and tools that you can, assess your risk, and, incorporating your experience and knowledge about your cropping system, make the best decisions you can. Experts also suggest you follow the driving principle of fertilizer management, the 4 Rs: right product, right time, right place and right rate.

Jan. 27, 2012, Dorchester, ON - he Canadian Food Inspection Agency (CFIA) has approved a new, liquid formulation, nutrient seed treatment for use on wheat, oats, barley and corn. Awaken ST is manufactured by Loveland Products and available from UAP Canada Inc., as part of its Nutritionals portfolio of products. Awaken ST is a patented, seed-applied nutrient, with a micronutrient package including 5% zinc plus boron, copper, iron, manganese and molybdenum.

“Awaken ST puts nutrients where a germinating plant needs them – on the seed,” says Eric Gregory, product manager with UAP Canada Inc., based in Oak Bluff, Manitoba. “It’s a unique, nutrient-based product that helps develop a larger, more extensive root system, quicker emergence, greater plant biomass and improved plant health and vigour. All of this supports the goals of progressive growers in pursuit of maximum yield and return on their crop inputs investment.”

Unlike other registered seed-applied nutrients, Awaken ST comes in an easy flowing liquid formulation that can be applied using traditional seed treating equipment. According to Loveland Canada general manager, Jeff Crampton, “Awaken ST can be applied on its own, blended or applied sequentially with traditional chemical-based fungicide or insecticide seed treatments.”

Research on Awaken ST from North Dakota State University has demonstrated a significant increase in plant emergence and an 8 percent-plus yield increase when compared to untreated seed.1

About UAP Canada

Founded in 1978, United Agri Products (UAP) is the largest distributor of agricultural and non-crop inputs in Canada and the United States and is an emerging developer of their own proprietary innovative new technologies. UAP is helping growers meet the challenges of higher crop yields and healthier production practices by offering a comprehensive line of proven crop protection products, including plant nutrients, herbicides, fungicides, insecticides and specialty products. These products are available to Canadian growers through national and regional dealers. UAP Canada is headquartered in Dorchester, Ontario, with regional offices in Oak Bluff, Manitoba and Langley, British Columbia and reps in every corner of the country.

About Loveland Products

Loveland Products offers a complete line of high performance inputs including seed treatments, plant nutrition, fertilizer, adjuvant and crop protection products. The company works to bring new and unique chemistries to the marketplace to provide innovative solutions to agricultural and professional non-crop (including turf and ornamental, pest control operations, forestry and vegetation management) industries.

Urea is the dominant source of granular nitrogen fertilizer used on the prairies. Unfortunately, for growers who want to apply their N requirements in or near the seedrow, this product can have an adverse effect on seed germination and crop establishment at higher rates of application. The risk of germination damage from urea placed in close proximity to the seed also varies significantly with crop type and soil conditions.

Know the seedbed utilization factor (SBU) for your seeder.

Original guidelines quite restrictive
The original guidelines establishing ‘safe’ limits for seedrow applied urea were developed for relatively narrow double-disc openers that placed the seed and fertilizer close together. Under these conditions, researchers suggest the amount of urea-based nitrogen that could be placed in the seedrow for cereal crops be limited to a maximum of 20 to 25lb/ac of N. However, as growers adopted seed openers that could place seed and fertilizer in wider bands, it has become obvious that these original seedrow N guidelines were too restrictive.

Table 1. SBU ranges associated with some typical prairie seed openers.
Opener style
Percentage SBU
Knives
5 to 10
Disc
7 to 10
Hoe
12 to 15
Spoons
15 to 30
Small sweeps
25 to 40
Large sweeps
40 to 60
Discers
50 to 70
Note: Values shown are only estimates. Actual SBU values that are determined under field operating conditions should be used for estimating 'safe' rates of seedrow N applications.

Increased seedbed utilization
Researchers working at Westco Fertilizers determined that the rate of urea N that could be safely placed in the seedrow was directly proportional to the percentage of the total available seedbed utilized (SBU) for placement of seed and fertilizer. In other words, for a given soil, the wider the seedrows and the narrower the spacing between seedrows, the greater the amount of urea N that would be tolerated with the seed. Refer to the table listing the various types of openers and their estimated ranges of potential seedbed utilization (see Table 1).

Calculating your SBU
The percent SBU typical of your seeding equipment can be easily calculated if you can determine the effective width of seed and fertilizer spread that is achieved by your opener during field operation. For example, an opener could spread seed and fertilizer over a width of 3.5 inches with a space between the seed openers of nine inches. The SBU for this opener can be determined by multiplying the seed spread by 100 (i.e. 3.5in x 100 = 350) and then dividing that value by the seed opener spacing (i.e. 350 divided by 9in = 39 percent).

Similarly, for an opener that has an effective spread width of two inches and a row spacing of 10 inches, the SBU is 20 percent. Keep in mind that the degree of seed spreading can be influenced by soil conditions as well as the speed of seeding.

Table 2. Maximum allowable seed-placed urea N (lb/ac) for cereals as influenced by SBU and seedbed soil textural category under ideal seedbed moisture conditions.
-
Light texture
Medium texture
Heavy texture
Percentage SBU
Sandy loam-light loam
Loam-clay loam
Clay-heavy clay
10
15 to 20
25 to 30
27 to 32
20
22 to 27
30 to 35
34 to 39
30
30 to 35
37 to 42
42 to 47
40
35 to 40
45 to 50
49 to 54
50
40 to 45
52 to 57
57 to 62
60
45 to 50
59 to 64
65 to 70
70
50 to 60
68 to 73
72 to 77
Adapted from Westco Seedrow Nitrogen Guidelines. J.T. Harapiak and N.A. Flore. December 1993.
Note: These guidelines do not apply to hulless barley.

Establish soil texture to determine ‘safe’ upper limit
To use this table of guidelines you must know the correct soil textural grouping for your land. Many growers still confuse soil colour with texture. In fact, colour has nothing to do with texture. You can have a dark or a light coloured soil in any of the three textural groupings included in the table. Basically, texture is a reflection of the clay content of your soil. The 'Light Texture' category is not a reflection of soil colour, but rather of a low clay content and a higher sand content. The higher the clay content, the more N can be tolerated in the seedrow (see Table 2).

Guidelines apply to favourable seeding conditions
Soil conditions within a field can vary quite considerably. These guidelines were developed assuming that the crop is being seeded under the following favorable conditions:

  • excellent seedbed moisture,
  • soil is free of lime (i.e. eroded knolls),
  • soil is free of excessive salts (i.e. saline/alkali patches),
  • seeding depth is not excessive,
  • seed is of good quality,
  • minimal field variability in texture and organic matter content.

‘Safe’ rate significantly influenced by field variability
Keep in mind that if the field being seeded is not fairly uniform with respect to topography as well as soil chemical and physical factors, then it is the poorest part of the field that is generally most vulnerable to seed germination damage. Therefore, from a seed safety point of view, unless you are prepared to vary the rate of seedrow applied N within a field, it will in effect be the poorest or most vulnerable part of the field that will establish the practical upper ‘safe’ limit for the field.

The ‘safe rate’ will depend on the conditions at any location in the field.

Reduce rates by 50 percent if seedbed moisture is less than ideal
The guidelines contained in the table only apply to seedbeds with ideal moisture conditions. If the seedbed moisture is less than ideal, the ‘safe’ upper limit for application of urea N with the seed must be decreased by 50 percent (i.e. cut in half) in order to avoid the risk of incurring significant stand damage and delayed crop maturity.

Caution warranted with more sensitive crops
Oilseed crops such as canola and flax are generally much more sensitive to damage from seedrow applied nitrogen. Under ideal seedbed moisture conditions, the ‘safe’ rate for these two crops, is probably in the range of 10 to 20lb/ac lower than the rates indicated in the table for cereal crops. Other more sensitive crops include canary seed, mustard and hulless barley.

Growers have exceeded guidelines after experimentation
I must admit that these published guidelines are in fact deliberately cautious because of the many unknowns that exist in making a recommendation from a distance. Some growers working soils with a lesser degree of field variability have in fact been experimenting, with some success, by exceeding these guidelines under favourable seedbed moisture conditions. However, such a step should only be considered with caution and only after some experimentation in a small, representative part of a field. Check the crop carefully for signs of seed damage, delayed emergence, loss of plant stand, excessive tillering and delayed maturity in the strips with higher rates of seed applied N. -30-

John Harapiak has approximately 40 years of western Canadian based fertilizer related experience. He will continue to contribute stories to Top Crop Manager. He can be contacted by e-mail at: This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

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