Category Archives: Soil/Water Science

HOW PLANTS INTERACT WITH BENEFICIAL BACTERIA

PHYSORG. 12 January 2016.  Scientists have wondered for years how legumes such as soybeans, whose roots host nitrogen-fixing bacteria that produce essential plant nutrients out of thin air, are able to recognize these bacteria as both friendly and distinct from their own cells, and how the host plant’s specialized proteins find the bacteria and use the nutritional windfall.

Now a team of molecular biologists led by Dong Wang at the University of Massachusetts Amherst, working with the alfalfa-clover Medicago truncatula, has found how a gene in the host plant encodes a protein that recognizes the cell membrane surrounding the symbiotic bacteria, then directs other proteins to harvest the nutrients. Details appear online in the January edition of Nature Plants.

As Wang explains, plants often recruit microbes to help them satisfy their nutritional needs, offering the products of photosynthesis as a reward. A process used by most land plants depends on a symbiotic relationship with mycorrhizal fungi. These form structures known as arbuscules that help plants capture phosphorus, sulfur, nitrogen and other micronutrients from the soil. This method is akin to scavenging, Wang says, because the amount of nitrogen available in soil is quite limited.

By contrast, the less common process, found mostly in legumes, goes one giant step further: it uses bacteria called rhizobia, which live in root nodules and fix nitrogen from the air and make it into ammonia, a plant fertilizer. Symbiosis with rhizobia means legumes can make ammonia by fixing nitrogen in the air, which at 78 percent of the atmosphere, is “essentially limitless,” the biochemist adds.

Thanks to this feat, legume plants can get as much nitrogen fertilizer as they need, rather than relying on often scarce nitrogen in the soil. This is why beans are so nutritious, Wang notes. “The next time you eat your tasty tofu or edamame, you have those little bacteria, and their ‘marriage’ with legumes to thank.”

“Talk to anyone in our field, and the dream is to make it possible for our crops that can’t fix nitrogen to get that ability,” Wang suggests. “This discovery moves us one step closer. Beans are special, but what our result says is they are not that special because some of the basic infrastructure is already there in plants that use arbuscular mycorrhizal fungi instead of nitrogen-fixing bacteria, which no one understood before.”
Read more at: http://phys.org/news/2016-01-interact-beneficial-microbes-soil.html#jCp

MICROBES ADDED TO SEEDS MAY BOOST CROP PRODUCTION

Scientific American 6 January 2016. Nathan Cude pulls open the top of a white Tupperware container labeled Q8R, which holds one of the hundreds of samples of American farmland he’ll handle in a year. The dark brown soil inside looks lifeless, but the microbiologist at Novozymes smiles as he utters one of his favorite lines: A spoonful of soil contains about 50 billion microbes, representing up to 10,000 different species. The number of organisms in the container surpasses the number of people who have ever lived on Earth.

Communities of soil-dwelling bacteria and fungi are crucial to plants. They help plants take up nutrients and minerals from the dirt and can even extend root systems, providing more access to food and water. They also help plants grow, cope with stress, bolster immune responses and ward off pests and diseases.

Now scientists at agricultural companies are digging through the dirt, like prospectors panning for gold, to find the exact microbes that make specific crops grow better. Agribusiness firms Novozymes and Monsanto are leading the way by coating seeds with microbes, planting them on farms across the U.S. and harvesting the crops to see how they fared. The two companies, through their BioAg Alliance, have just concluded the world’s biggest field-test program of seeds laced with promising microbes. This past autumn they harvested a variety of crops, planted using seeds with more than 2,000 different microbial coatings, grown in some 500,000 test plots from Louisiana to Minnesota, and they have been busily analyzing the outcomes. They will announce early results today. But they gave Scientific American a peek at their operations, and their aspirations, prior to releasing any findings.

Ultimately, such microbial agricultural products could significantly reduce fertilizer and pesticide use, easing the burden farming imposes on the environment and potentially helping a farmer’s bottom line by reducing costs or increasing crop yields. The research is the beginning of an ambitious movement to replace chemistry in agriculture with microbiology.

Field trials are the key. “There is nothing that translates a greenhouse result to a field result,” says Thomas Schäfer, vice president of bio-ag research at Novozymes, and Cude’s boss. “Because the field is so complex, we have to test [seeds] in the field directly.”

A growing need
The world’s population is predicted to reach nine billion by 2050. With more mouths to feed, agricultural yields will have to nearly double. Climate change isn’t helping: droughts, floods, rising salinity and soil erosion are creating harsher growing conditions. Many pests and pathogens are developing resistance to pesticides. Chemical fertilizers only partly address the problem, and some studies show they contaminate groundwater, possibly contributing to human illnesses, and amplify harmful algae blooms in rivers and oceans. Scientists are hoping microbes can provide a viable alternative.

That solution could also alter the economics of big ag companies. Today the market for agricultural biologicals, such as natural pest controls, plant extracts and beneficial insects, is about $2.9 billion a year [updated Jan. 7, 2016]—a mere fraction of the $240 billion brought in by traditional fertilizers and pesticides, according to the alliance. Monsanto thinks the microbial market could grow substantially. Microbials have faster development cycles and fewer regulatory hurdles than other agricultural products, which can take 10 to 14 years to move from idea to market. And if widespread use lessens dependence on fertilizers and pesticides, that could ease public wariness of industrial farming.

The notion of bio-agriculture isn’t new. In 1888 the Dutch microbiologist Martinus Beijerinck discovered that the roots of leguminous plants were inhabited by a bacterium called rhizobium, which could take nitrogen from the air and convert it into a form the plants could use. Farmers and gardeners have been sprinkling packets of powdered rhizobiaon their peas and beans ever since. One by one, other microbes have been transformed into products, like biofungicides and biopesticides. But it wasn’t until recently that new DNA-sequencing tools allowed researchers to see the vast, complex microbiome, known as the rhizosphere, living in, on and around plant roots. A 2012 report written by the American Academy of Microbiology, titled How Microbes Can Help Feed the World, argued that tapping into this resource could generate products that “increase the productivity of any crop, in any environment, in an economically viable and ecologically responsible manner.”

The tricky part is figuring out which of the billions of members of the rhizosphere to go after first. Novozymes sends out teams of researchers to collect soil samples from private farms, which they bring back to the company’s labs in Research Triangle Park, N.C., where scientists like Cude process them. Although each sample might contain billions to trillions of microorganisms, only about 1 percent of will grow in the lab. Those that do often materialize in petri dishes in a dazzling array of shapes and colors: thin streaks of indigo blue, droplets of mustard yellow, a fuzzy asterisk of charcoal gray, a giant glob of blood red. Each microbe’s genome is sequenced (decoded) and checked against a database of known pathogens; any matches are discarded whereas the rest move on to the next phase.

The researchers test the remaining contenders to see if they could be used as one of two things: inoculants, which help plants take up nutrients, or bio-control products that help protect against disease and pests. One test checks if the microbes help plant roots better absorb nutrients such as nitrogen or break down inorganic soil phosphates so plants can use them. Another test assesses whether the finalists could offer protection against plant diseases or pests. For example, parasitic nematodes cause more than $120 billion in damage to plants worldwide. Jennifer Petitte, a zoologist at Novozymes, shows me a dish writhing with these tiny worms, which are barely visible to the naked eye. She adds promising batches of microbes to the dishes to determine if any can paralyze or kill the nasty pests.

Vials containing the best microbial candidates travel down the street to another Novozymes laboratory, where they are grown in large flasks filled with various formulations of rich broth, ranging from pale yellow to amber to almost black. Bill Throndset, a microbial physiologist at Novozymes, tells me the flasks’ exact contents are a trade secret, “like the recipe for Coca-Cola.” None of the microorganisms are genetically modified or engineered; instead, they are derived and cultured from soil samples. After each batch is cultured in its favorite media, it is cryopreserved and stockpiled, much the same way eggs or sperm are stored in banks. They’ll need to be alive and healthy when spring arrives and they are applied to seeds, so when the seeds germinate they can become part of the rhizosphere as soon as the plant takes root. “We essentially only have one experiment a year, so we have to get it right,” Throndset says.

Shortly before the growing season, the microbes are shipped a Monsanto facility in Saint Louis, where they are sprayed on seeds in big stainless steel bowls, like giant popcorn holders. In 2014 Monsanto planted seeds coated with hundreds of different microbial strains on around 170,000 plots, ranging from three by three to three by 10 feet in size. In 2015 the company greatly expanded the trial to more than 2,000 types of microbes on some 500,000 plots. Beside each test plot, the company planted a control plot with no microbe-laden seeds, creating a checkerboard effect across portions of the U.S. South and Midwest.

More bushels per acre
In October and November 2015 researchers harvested the crops and began crunching the numbers to determine which if any microbes made a difference. Many of the 2,000 coatings turned out to have no effect. But the top five increased corn yields by an average of four to five bushels per acre and soy yields by an average of 1.5 bushels per acre. The early results “look great,” says Jeff Dangl, a scientist at the University of North Carolina at Chapel Hill who studies the plant microbiome and is not involved with the experiments. “However, typically field trials have to run for seven years before anybody believes them. So the jury is still out. After we see several years’ worth of data, then we will have a more complete picture of which microbes are doing what.”

Nevertheless, the alliance says it plans to launch one of the five microbes as a product in 2017—an inoculant based on fungus found in cornfield soil. Novozymes’ Schäfer admits that even with all of the laboratory testing, he and his colleagues are still making educated guesses when choosing which microbes to send into the field. He hopes after multiple rounds of field testing, with top performers returning year after year, that patterns will emerge to help them predict which strains of microbes will benefit specific crops. The alliance will again field-test thousands of strains in 2016.

Unleashing microorganisms into new environments—particularly when the end product is destined for our kitchen tables—can raise concerns, some more valid than others. For example, Dangl says it is possible that messing with the microbial milieu might affect the taste of a particular crop, much like the composition of soil is known to influence the flavor of wine. There is also a risk that seed coatings, like many agents applied to a field, could slough off one crop and contaminate another. Some proponents don’t see a downside to sharing these “plant probiotics,” however, saying they would at best be beneficial to other crops and at worst have no effect.

Gwyn Beattie, a professor of biology at Iowa State University in Ames and one of the contributors to the American Academy of Microbiology report, has been following Novozymes’ efforts for years. She thinks the biggest concern is not necessarily that newly introduced microbes will grow and spread to other crops but rather that they won’t stick around long enough to do their job in the first place. “My analogy is if you throw one person [at a time] into New York City, the vast majority of people you throw in there do not change New York City. Every now and then there is one that will change the world, but it is not very likely to happen,” Beattie says. “It is like that in a microbial community. Introducing organisms rarely has an impact at all, and that’s actually the biggest frustration.” As a result, she argues, there will always be a need for chemical pesticides and fertilizers, but perhaps in smaller amounts as microbes are added to the mix.

The transient nature of the microbiome is one of the reasons Novozymes and Monsanto are currently field-testing microbes coated on seeds, rather than using other applications like sprays or root soaks. Hitting plants when they are germinating and sprouting, even if the effects are fleeting, could put them on track to be healthier as they grow. Although Schäfer would love to find a single blockbuster microbe, his scientists are also beginning to realize that bigger benefits may come from sets of microbes working together. With thousands of species in one gram of soil, the possible combinations are endless. Right now they are testing the species one by one, and they will wait until they have strong enough data on the singletons before testing combos.

Despite the challenges, Schäfer maintains microbes are poised to make a lasting impact on modern agriculture. Existing microbial products such as Novozymes’ Met52, a fungus that limits vine weevils, are already used on millions of acres; if seed coatings take off, that number could jump. The two firms think bio-ag products will be used on up to 500 million acres, or 50 percent of U.S. farmland, by 2025. “Companies like Monsanto, Bayer, Syngenta and BASF are working on microbes because they believe [the technology] has the potential to reduce chemistry and allow us to live more sustainably,” Schäfer says.

THE ROLE OF GYPSUM IN AGRICULTURE

While farmers have used gypsum (calcium sulfate dihydrate) for centuries, it has received renewed attention in recent years. This resurgence is due in large part to ongoing research and practical insights from leading experts that highlight the many benefits of gypsum.

Major Benefits Of Gypsum

1. Source of calcium and sulfur for plant nutrition. Plants are becoming more deficient for sulfur and the soil is not supplying enough it. Gypsum is an excellent source of sulfur for plant nutrition and improving crop yield. Meanwhile, calcium is essential for most nutrients to be absorbed by plants roots. Without adequate calcium, uptake mechanisms would fail. Calcium helps stimulate root growth.

2. Improves acid soils and treats aluminum toxicity. One of gypsum’s main advantages is its ability to reduce aluminum toxicity, which often accompanies soil acidity, particularly in subsoils. Gypsum can improve some acid soils even beyond what lime can do for them, which makes it possible to have deeper rooting with resulting benefits to the crops. Surface-applied gypsum leaches down to to the subsoil and results in increased root growth.

3. Improves soil structure. Flocculation, or aggregation, is needed to give favorable soil structure for root growth and air and water movement. Clay dispersion and collapse of structure at the soil-air interface is a major contributor to crust formation. Gypsum has been used for many years to improve aggregation and inhibit or overcome dispersion in sodic soils.

Soluble calcium enhances soil aggregation and porosity to improve water infiltration (see below). It’s important to manage the calcium status of the soil. It’s every bit as important as managing NPK.

In soils having unfavorable calcium-magnesium ratios, gypsum can create a more favorable ratio. Addition of soluble calcium can overcome the dispersion effects of magnesium or sodium ions and help promote flocculation and structure development in dispersed soils.

4. Improves water infiltration. Gypsum also improves the ability of soil to drain and not become waterlogged due to a combination of high sodium, swelling clay and excess water. When we apply gypsum to soil it allows water to move into the soil and allow the crop to grow well.

Increased water-use efficiency of crops is extremely important during a drought. The key to helping crops survive a drought is to capture all the water you can when it does rain. Better soil structure allows all the positive benefits of soil-water relations to occur and gypsum helps to create and support good soil structure properties.

5. Helps reduce runoff and erosion. Agriculture is considered to be one of the major contributors to water quality, with phosphorus runoff the biggest concern. Gypsum helps to keep phosphorus and other nutrients from leaving farm fields. Gypsum should be considered as a Best Management Practice for reducing soluble P losses.

Using gypsum as a soil amendment is the most economical way to cut the non-point run-off pollution of phosphorus.

PUBLICATION OFFERS PHOSPHORUS APPLICATION TIPS

Purdue University. 12 November. A Purdue Extension publication offers farmers tips on phosphorus applications by focusing on four simple principles.

The publication, Tips for Environmentally Friendly Phosphorus Applications, is intended to help farmers better understand how and when to apply phosphorus fertilizers to their fields in a way that isn’t damaging to the environment.

“The fast and simple approach, such as broadcast P fertilizer application, is not the best approach environmentally,” says co-author Tony Vyn. “The dissolved P in all P fertilizers is water soluble and can become an environmental hazard under certain weather conditions following application to the soil surface with no incorporation.”

The tips correspond to the “4R Principles,” which are specific to Corn Belt cropping systems of differing tillage and crop rotations:

  • Right rate: Apply the correct rate of P fertilizers; test your soil, and only apply fertilizer where it’s needed.
  • Right source: Understand the amount of phosphorus that is in the fertilizer and account for the other nutrients it contains.
  • Right time: Applying P fertilizer at the wrong time can be detrimental to water quality, so avoid applying it just before a heavy rain is expected and consider split applications and immediate incorporation to reduce risks.
  • Right placement: Placement choices, such as broadcasting and shallow or deep banding, can affect the environment more than crop yield; tillage practices also can affect placement options.

The publication is available free for download at Purdue Extension’s The Education Store. Search for product number AY-386-W.

HOW TO USE AG GYPSUM AND LIME TO IMPROVE SOIL

Hay & Forage Grower.  21 September 2015.  Fall is an ideal time to apply soil amendments that enhance soil chemistry and improve soil physical characteristics. Agricultural soils with ideal pH levels and good soil structure – with well-aggregated soil particles and plenty of pore spaces for air and water movement — are important for crops to thrive.

Ag lime and gypsum are two common soil amendments that impact soil quality but sometimes there is confusion about their purposes and when to use one or the other amendment.

Ag lime is an acid-soluble material, often calcium carbonate or magnesium carbonate, applied to cropland to raise the pH of acidic soils. Acid soils, or soils with excess active hydrogen (H+), can curb a growing plant’s ability to reach its potential by limiting nutrient availability and biological activity. Scientists recommend soil pH of 6.2 to 6.8 as ideal for most crops.

Gypsum is calcium sulfate dihydrate. It is not acid soluble and is not recommended for altering soil pH. Gypsum is used to add sulfur and improve soil particle aggregation. The sulfate in gypsum binds with excess magnesium (an element which causes poor soil structure) in the soil to form Epsom salts that easily move down through the soil profile. The magnesium is then replaced by calcium to improve soil structure and produce better results for water holding capacity, root development and soil quality.*

“We use lime where we have very low calcium and low pH,” says Cory Schurman, national sales manager with GYSPOIL brand gypsum. “We use calcium sulfate (gypsum) where we have more neutral pH but where we have higher magnesium levels and lower calcium levels.”

Schurman adds that some growers use gypsum the year before they apply lime in order to lower magnesium levels and improve the efficiency of liming. “They work well together and tend to complement each other,” says Schurman.

Gypsum Boosts Soil Nutrition

AgriNews. Demand for gypsum, a tool that farmers use to make soils healthy and manageable, is on the rise across the state and country.  Farmers and gypsum distributors met in Indianapolis recently to learn about Gypsum.

“Essentially, gypsum is calcium sulfate, it has the ability to change the chemistry in the soil in such a way so that compacted clay soils become softer and mellower.”

Gypsum allows water and air to move through soil, making it aerated and moist. Farmers who use gypsum tend to notice that their implements move easier.

Rodney Rulon, a corn and soybean farmer in Arcadia, applies gypsum in the fall and sometimes in early spring, depending on the weather.

“I’ve been using gypsum for 10 years,” he said. “We were fairly early adopters, but there were certainly other people we learned from.

“We’re working on two things — one is soil structure: To improve the soil and water infiltration, to help get water down through the roots. Secondly, it’s our sulfur source for soil nutrition.”

Rulon said that he has seen soil quality improvement since adding gypsum to his fields.

“Gypsum has been used in parts of the world for centuries,” Chamberlain said. “Only recently have we had new supplies of gypsum in U.S. agriculture. As a result, there’s a growing demand for gypsum. A lot of farmers are using gypsum now.

“We did a survey and report on farmers that have used it long term versus short term. Gypsum users are seeing benefits that increase over time, including yield, changes in their need for nutrient applications and better water infiltration.”

[Farmers interested in gypsum should first get a soil test and then talk to us at Fertile Soil Solutions]

 

FEED THE SOIL FIRST

Mississippi State University.  January 2015.  Sometimes we need to go back to square one and run the checklist to make sure we have not forgotten something. This is true in any kind of activity but it is especially critical for the production of crops. I hesitate to say it but farmers whether large or small are sometimes the worst procrastinators when it comes to getting the land ready for the next crop.

One of the most important things I have learned about soil, not only from professors but from successful farmers and gardeners, is that you never stop improving the soil. This is necessary if you want your crops to grow well and produce the kind of yields and quality that you can be proud of and that also can pay good dividends at the marketplace. You don’t just go out one day and decide to plant a crop if you expect to be successful.

It takes planning and preparation to make it all work right. I know that some people make it look so easy that you think anyone can do it, but these people who have the proverbial “green thumb” also have several other attributes, not the least of which are a bright minds and willingness to apply their knowledge, and patience to begin ahead of time and see the work through to the end without getting distracted by things that don’t matter.

It also helps to be the kind of person who enjoys working with the land and accepting the challenge to take the gifts we have come together to produce good results. I know that I have said several times before that there is no more beautiful sight than a field of dew-covered corn glistening in the sun rises on a June morning. If things like that don’t strike you as special you may need to let someone else grow your crops or your garden.

This time of year there are lots of decisions to be made as we prepare for another crop. Farmers who grow big acres of crops like corn, cotton, and soybeans have to start thinking about their rotation plans, what kind of weed control strategy to employ, which varieties to plant, and this year they have another issue in the form of a new farm bill that requires that some pretty complicated questions be answered, but the one thing that should be standard procedure for them is that the soil must be fed so that their crops can produce well. And really, the other decisions don’t really matter much if this work is not done correctly.

Soil test recommendations must be followed as well as possible regardless of whether you are planting a thousand acres of cotton or a thousand square feet of vegetables. The principles are the same. You are about to depend upon the soil to feed you so you need to feed it first.  It comes down to knowing how, as I once heard a wise old farmer say “It’s not just knowing what to do, it’s doing what you know.”

These days we hear a lot of people talking about being prepared for unexpected events. These people refer to themselves as “preppers”. The original preppers were farmers and gardeners who developed the skills to make the land produce their food. If you have not learned these skills it’s time you did.

 

Soil Testing Is Critical

Maintaining a healthy balanced soil requires consistent effort and advanced planning. This is the best way to determine how much nutrition is available to feed your crops from planting to harvest. Let us help you create a custom fertility program that pushes your yield to the max while helping you maintain a healthy, balanced soil.

Organic Growers: There Are Organic Gypsum Products Available

EcoGEM. Can gypsum be applied on organic farms?

Commercial farmers, organic farmers, home owners, turf managers and others can benefit from application of gypsum (calcium sulfate) in remediating salinity and sodium issues and improving soil structure. However they can’t all use the same sources or gypsum.

Mined gypsum can be OMRI® listed (Organic Materials Review Institute®), which OMRI is a national nonprofit organization that determines which input products can be used in organic crop production. Many natural gypsum suppliers have gotten this certification. OMRI listed products can be used in certified organic operations under the USDA National Organic Program. Continue reading Organic Growers: There Are Organic Gypsum Products Available

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