California Fruit and Vegetable

Tag: Crop Science Society of America

  • How Do Nutrients Get Into My Vegetables?

    Like all living organisms, vegetables need nutrients for their proper growth and development. But where do they get their mineral nutrients from? The answer is soil. Okay, the next question is, how do nutrients go from the soil and into the vegetables?

    The three processes responsible for nutrients from the soil reach the plant are diffusion, mass transport, and root interception. I know it seems to be complex to understand, but I promise it is not.

    Diffusion

    When the concentration of nutrients is higher in the soil than in the plant root, then the nutrients in the soil will move from a region of higher concentration (soil) to a region of lower concentration (vegetable). Potassium and phosphorus are examples of nutrients that get into the vegetables by diffusion.

    Mass transport

    Nutrients move to the roots via water. As plants transpire water, it draws water and nutrients from the soil up through the root system. Mass transport accounts for nutrient acquisition of mobile nutrients, such as nitrogen and sulfur.

    A radish plant with soil pulled aside to demonstrate the root system. Plants get their nutrients from the soil – and if the soil is deficient in nutrients, the resulting crop will be too. Credit: Carlos Bonini Pires

    Root interception

    Vegetable roots grow through the soil to meet nutrients. As the root grows through the soil it generally only comes in contact with about 1% of soil volume. Good soil structure is essential in the process of root interception. Soil compaction can significantly limit root growth and interception with nutrients throughout the soil. Some important macro and micronutrients such as calcium, magnesium, iron, manganese, and zinc are absorbed by root interception.

    Of course, some nutrients are absorbed in more than one way. For example, iron and zinc can be absorbed by three different methods. As you can see, there are a lot of variables that may impact how vegetable acquire their nutrients.

    Moving within the plant

    Once the nutrients get inside the plant, they can move upward to the leaves and developing vegetables. How? Like a human body, plants also have a vascular system. Rather than a bloodstream, they have xylem and phloem. The Xylem distributes water and dissolves nutrients upward to the plant, from the roots to the leaves. The phloem carries nutrients downward, from the leaves to the roots (photosynthesis). In simple words, the root is the mouth and xylem and phloem are the veins of a “plant body.”

    Checking soil nutrients

    Soils nutrient concentration is crucial for ensuring high nutrient content vegetables. If the soil has few nutrients, no matter how the plant tries, it will not be able to acquire the nutrients it needs for good yields and plant health.

    That is why soil testing is important, and correct fertilization might be needed. Understanding how nutrients are absorbed is vital for a placement strategy. Phosphorus and potassium are nutrients with low mobility and are absorbed by diffusion, so it is important to place them near the plant. On the other hand, nitrogen can be spread over the plants since it is mobile in the soil. This is true whether you are applying organic or mineral fertilizer.

    In agronomy, we pay attention to the nutrient 4R’s: right source, right rate, right time, and right place. This refers to choosing the right type of nutrient or fertilizer, applying at the right amount, when the plant can use it the most, and in the right location. By applying these principles to your home garden, you can increase your yields and create more nutritious produce for your next meal! — By Carlos Bonini Pires, Kansas State University

    An illustration of a soybean plant growing in nutrient-rich soil, producing nutrient-rich soybeans on the left. On the right, a soil that has fewer nutrients will result in soybeans with less nutrients. Credit: Jim Toomey

    American Society of Agronomy, Soil Science Society of America, Crop Science Society of America: Collectively, these Societies represent more than 12,000 individual members around the world. Members are researchers and professionals in the areas of growing our world’s food supply while protecting our environment. Together we work toward solutions to advance scientific knowledge in the areas of agronomy, crop science, and soil science.

  • Juicy Research Unearths New Genome Within the Tomato Family

    Hidden beneath the delicate, red skin and juicy flesh of a tomato is a wealth of nutrients and genetic makeup. With recent research on the first genome of a species in the tomatillo tribe (part of the tomato family), we now have a better idea of how this vital plant family came to be.

    Put simply, a genome is a complete set of DNA (genetic material) in a plant. The genome contains all the information needed for a plant to develop and grow. When scientists assemble genetic sequences to build an entire genome– a lot like completing a puzzle – this helps them predict things like how a plant will grow (straight or crooked) and what the fruit might look like (thin or thick skinned.) This information is important for understanding how different varieties come to be and is key for breeding better crops.

    “The tomato family is simply the most fascinating family. It consists of plants that are major crops, invasive weeds, important medicines, beautiful bedding plants, and many wild species that are crop relatives,” says Stacey Smith, a professor at the University of Colorado-Boulder.

    This research was published in The Plant Genome Journal, a publication of the Crop Science Society of America.

    A closer look at the flower and fruit of an Iochroma cyaneum shrub grown in southern Ecuador. Like its relative, the tomatillo, this shrub’s fruit has an enlarged husk growing around it. Researchers recently were able to create a full genetic sequence for the plant, called the genome.

    Smith led the work on the sequencing the genome of Iochroma cyaneum, a wild shrub in the tomatillo tribe of the tomato family. Iochroma displays striking blue flowers but isn’t widely grown. Scientists like Smith can learn how important plant families evolved by collecting many genomes from different sub-species.

    “Unlike most plants in the family with sequenced genomes, it is not a crop species. It’s also the only member of its entire tribe with genome assembled to the level of chromosomes,” says Smith. These unique traits make the new genome even more valuable to understand how the broader family evolved.

    After sequencing the Iochroma genome and assembling the sequences into chromosomes like a puzzle, Smith’s research team compared it to other members of the family. The broader tomato family has almost 3,000 species. Some of these species, like belladonna, are poisonous to humans. Forty species have been domesticated, which include potatoes, eggplants, and hot peppers, in addition to tomatoes. All of these plants belong to the family are also called “nightshades.” In the puzzle example, this means that they all have a similar set of puzzle pieces, up to a point. From there, their puzzle pieces are different.

    The genome told researchers that Iochroma was part of the family known as the “berry clade.” This subgroup forms “berries” which are juicy fruits with many seeds, like tomatoes and hot peppers. But the scientists were surprised to find that the family relationships within this clade were far from clear. The genetic evidence was uncertain about which species were most closely related. Biologists call this kind of disagreement “discordance.”

    “This kind of disagreement often arises when lineages reproduce quickly within different species,” says Smith.  “That may be what happened tens of millions of years ago when fleshy-fruited berries from this family burst onto the scene. As a result of this discordance, we can’t make definitive statements about which species are more closely related.”

    A wild Iochroma cynaeum growing in southern Ecuador. South America is home to many diverse members of the tomato family, which also includes potatoes and chili peppers. Researchers can learn how important plant families evolved by collecting genomes from different sub-species. This information can inform future breeding efforts.

    Still, the new genome gives a new look into the evolution of the family. One clue is how the genes have moved around. As species evolve, genes can move from one chromosome to another. Plants adjust efficiently to these changes. But Iochroma offered up a surprise. Its genome shuffling didn’t closely resemble any other sequenced genome, meaning the shrub has had its own unique evolutionary path.

    “With the addition of the lochroma genome, we are working towards understanding how genes have been shuffled around during the evolutionary history of the berry clade,” says Smith. “We have only scratched the surface in terms of understanding how this diversity evolved.”

    While the new research won’t produce a tastier tomato or tangier tomatillo right away, Smith says the family already offers a lot of flavors to the bold gardener. And, perhaps, an appreciation for the diversity offered by evolution.

    “I would encourage anyone who is curious about nightshades to get to know some of the lesser-known crops — try out golden berries, ground cherries, pepinos, wonderberries, or naranjillas!” says Smith. “There are even species that can be eaten as greens. Many of these will happily grow in northern climates and bring a lot more flavor than any tomato you can find on the grocery store shelf.”

    Funding for this research was supported in part by NSF-DEB 1355518.

    American Society of Agronomy, Soil Science Society of America, Crop Science Society of America: Collectively, these Societies represent more than 12,000 individual members around the world. Members are researchers and professionals in the areas of growing our world’s food supply while protecting our environment. Together we work toward solutions to advance scientific knowledge in the areas of agronomy, crop science, and soil science.

  • Getting to the Root of How to Grow Cowpea in Difficult, Dry Conditions

    Cowpea is an important crop in many parts of the world, especially sub-Saharan Africa. It is resilient and can grow in areas with little rainfall and low-quality soils. But as hardy as it is, cowpea yields can decrease by drought and low levels of soil phosphorus.

    A high-resolution root hair image taken from a cowpea seedling root sample. The image was taken after 14 days of growth on germination papers. Root hairs play important roles in cowpea tolerance to drought and poor soils. Credit: Saba Mohammed

    In a recent study, researchers determined cowpea root characteristics that could help the plants grow better in drier, low-phosphorus soils.

    “Developing cowpea varieties that can produce optimally under stressful conditions is vital,” says Saba Mohammed, lead author of the study at Ahmadu Bello University in Zaria, Nigeria. “These resilient cowpea varieties can help make more people food and nutrition secure.”

    The study was published in Crop Science, a publication of the Crop Science Society of America.

    Cowpeas are a key source of calories for millions of people across the world. They are rich in protein and other nutrients. Cowpea plants also have a variety of other uses. They can serve as animal fodder and green manure.

    Microbes in cowpea root nodules can increase soil fertility. These microbes make atmospheric nitrogen available to plants in the soil – a process called nitrogen fixation. Nitrogen fixation can be beneficial for farmers who cannot afford nitrogen-based fertilizers.

    Most cowpeas production is in semi-arid regions. Harsh environmental conditions and poor soils often hamper yields. “Our work established that certain root characteristics increased the yield of cowpea plants under drought or low soil phosphorus conditions,” says Mohammed.

    These root features include longer primary roots and higher numbers of lateral roots emerging from primary roots. Root hairs also play important roles in cowpea tolerance to drought and poor soils.

    For example, cowpea plants with longer, denser root hairs had higher yields when grown in low-phosphorus conditions. “That suggests these root hair features play crucial roles in acquiring phosphorus from sub-optimal soils,” says Mohammed.

    Scientists have long known that roots are a key part of how plants adapt to difficult environmental conditions. “The root system is half of the whole plant system,” says Mohammed. “Yet, it has been relatively under-explored in finding solutions to farming constraints.”

    Root systems have diverse strategies for extracting resources from soil. “For instance, plants with deeper roots produce better than those with shallow roots under limited water conditions,” he says. “On the other hand, those with shallow roots may be more suited to soils with suboptimal nutrients.”

    A field experiment on cowpea at the Institute for Agricultural Research in Minjibir Agricultural Research Station, Kano State, Nigeria. Cowpea crops are resilient and can grow in areas with little rainfall and low-quality soils. Credit: Saba Mohammed

    That’s because nutrients – like phosphorus – are often concentrated in the top layer of soil.

    For cowpea plants growing in dry and nutrient-limited soils, roots need to go deeper and spread wide and shallow.

    “Our study shows that we can focus on cowpea varieties with longer taproots for drought tolerance and higher numbers of shallower basal roots to extract soil nutrients,” says Mohammed.

    While root architecture can provide valuable information, examining root features of mature plants can be a time-consuming and exhausting process. Mohammed says it is easier and more economical to phenotype roots at the seedling stage.

    The study showed that examining roots of cowpea seedlings could help identify root features in mature plants that are beneficial for growth in challenging environments.

    “Our goal is to use the study results to breed new cowpea varieties,” says Mohammed. “These new varieties would perform optimally under limited water and low soil phosphorus conditions.”

    Many small-scale and subsistence farmers may be unable to afford phosphate fertilizers. The new cowpea varieties Mohammed describes would benefit these farmers tremendously. However, he explains that developing new varieties with desired root features can also be a valuable resource in systems where intensive irrigation and fertilizers are used. These cowpea varieties can help reduce production costs and minimize environmental pollution from excessive fertilizer use.

    American Society of Agronomy, Soil Science Society of America, Crop Science Society of America: Collectively, these Societies represent more than 12,000 individual members around the world. Members are researchers and professionals in the areas of growing our world’s food supply while protecting our environment. Together we work toward solutions to advance scientific knowledge in the areas of agronomy, crop science, and soil science.

  • New Herbicide Research Offers Sweet (Potato) Relief

    Sweet potatoes are a favorite Thanksgiving dish. Researchers at Clemson University have found that using “safeners” in addition to herbicides can help increase yields (Credit: Canva).

    Despite being beloved by most, sweet potatoes are often misunderstood. They’re unrelated to potatoes, for starters. And they’re even different from yams.

    Yet we can’t get enough. U.S. farmers have been increasing their production of sweet potatoes for years. And now the annual crop is worth more than $600 million.

    To grow the best crop, farmers have to help their sweet friends fight back against the usual suspects: weeds. Weeds will steal water, nutrients and even sunlight. Left unchecked, weeds will completely ruin a field of sweet potatoes.

    Herbicides can help, but they’re not a cure-all. Controlling broadleaf weeds is especially tough. That’s because sweet potatoes are also broadleaf plants, which means they will also be damaged by herbicides designed to attack broadleaf weeds.

    Enter “safeners.” These chemicals can make herbicides safer, hence their name. Recently, Giovanni Caputo and his team from Clemson University and the U.S. Department of Agriculture tested several safeners to see if they could help sweet potatoes. They discovered a few new formulas that might give a boost to farmers.

    The researchers recently published their findings in Agrosystems, Geosciences and Environment Journal, a publication of the American Society of Agronomy and the Crop Science Society of America.

    They set up their experiments in a greenhouse in South Carolina, a major sweet potato producing state. The scientists tested the herbicides bentazon and mesotrione on two varieties of sweet potatoes, “Beauregard” and “Covington.” The safeners they used included two types of plant hormones, which help the plant respond to stress. They also tested melatonin which is well-known for its role in the sleep cycle in humans, but it also occurs naturally in plants and is involved in growth and photosynthesis.

    The researchers found that different safeners worked better depending on the variety of sweet potato and the herbicide being used. For example, melatonin greatly reduced how much bentazon injured “Beauregard” plants. But the Covington variety didn’t benefit as much. Instead, “Covington” plants were best protected by ascorbic acid, better known as vitamin C.

    Similarly, melatonin and ascorbic acid provided the best benefit with the mesotrione herbicide. But the other plant hormone they tried didn’t help as much for either variety.

    To make sure the safeners didn’t affect the herbicide’s ability to kill weeds, The Clemson team tested the new formulas on Palmer amaranth and yellow nutsedge, both big weedy pests. Fortunately, the new formulas were still effective weed killers. It’s not entirely clear why the safeners helped the sweet potato plants but not the weed. But more tests might reveal what causes the different reaction.

    The upshot is that these new formulas seem promising for providing farmers with new tools to protect their crops from damaging weeds. They’ll need to perform more trials, especially in real farm fields, to perfect the formula. But a new herbicide system that could better protect sweet potatoes would be a boon to farmers and Thanksgiving tables alike. Now that’s a sweet deal.

    Funding for this research was provided by Agricultural Society of South Carolina.

    Comparison photos of (left) sweet potatoes infested with broadleaf weeds, which will reduce yields. (Middle) sweet potato field treated with the herbicide Bentazon only, which can harm the sweet potatoes. (Right) sweet potato field treated with Benzaton, but also with “safeners” melatonin and brassinosteroids. The safeners provided protection to the sweet potatoes but not the weeds, increasing sweet potato yields (Credit: Clemson University)

    American Society of Agronomy, Soil Science Society of America, Crop Science Society of America: Collectively, these Societies represent more than 12,000 individual members around the world. Members are researchers and professionals in the areas of growing our world’s food supply while protecting our environment. Together we work toward solutions to advance scientific knowledge in the areas of agronomy, crop science, and soil science.

  • Pumpkin Production can Benefit from Conservation Practices

    Pumpkins (Cucurbita pepo) are a common vegetable crop sold at local pumpkin patches and farmers markets, in addition to commercial production. In 2019, the value of harvested pumpkin was worth $180 million.

    In addition to the value of harvested pumpkins for commercial use (canned pumpkin, produce departments, etc.) pumpkins are also a staple crop in agritourism operations. In Kansas alone, there were 409 farms registered in the state in 2020. Agritourism enterprises have shown to benefit communities by connecting consumers with agriculture and help preserve farmland in rural and peri-urban areas.

    Vegetable crop production typically involves smaller acreages than agronomic production. However, farmers often rely on intensive cultivation of soil to prepare the seedbed for planting. Tilling also helps manage weeds.

    Agritourism enterprises have shown to benefit communities by connecting consumers with agriculture and help preserve farmland in rural and peri-urban communities. Shown here, a pumpkin patch where people can pick their own pumpkin as part of fall activities. Credit: Canva Pro

    Over time, extensive tillage can have negative effects on soil structure and microbial properties. Researchers in Kansas recently published a paper studying conservation practices for pumpkin production. The research was published in Soil Science Society of America Journal, a publication of the Soil Science Society of America.

    According to researcher Peter Tomlinson, “no-till production methods have been widely adopted by agronomic (field corn, soybean, wheat, etc.) growers throughout the United States. However, no-till practices for vegetable production in the Central United States are relatively rare. Mid-Atlantic States such as Pennsylvania, Virginia, and Maryland have adopted no-till practices for pumpkin and other large-seeded vegetable crops.”

    The study compared growing pumpkins in a biannual tilled control system with annual tilled systems that used cover crops. “This project is designed to compare systems, rather than individual effects of cover crops or tillage,” says Tomlinson. The authors reported the effects of a three-year project on dynamic soil properties.

    The annual systems used cover crops planted into the soil. They were terminated before planting the pumpkins. The team researched cereal rye and oat alone, as well as cereal rye with other cover crops mixed in. They performed the study over three growing seasons at two sites – Eastern and South-Central Kansas. Both sites have humid climates with warm summers, and loam-type soils.

    A field planted with pumpkins grown in a cover crop system with cereal rye. Cover crops have proven environmental benefits, though many vegetable growers in the Midwest have been slower to adopt this conservation practice. A recent study showed soil health benefits with no reduction in yield. Credit: DeAnn R. Presley

    At each of the study sites, soil health was assessed at two key times; plots were sampled 2-3 weeks after pumpkin planting, and immediately after pumpkin harvest.

    The main soil physical property that was affected by management systems used in this study was an improvement with the use of conservation systems in total soil aggregation and the presence of very large aggregates. Soil aggregates are small particles of soil held together with a glue-like substance. This is usually due to microbial activity. Soil aggregates help in the stability of the soil making it less prone to wind and water erosion.

    “Adding cover crops and reducing tillage in a pumpkin production system can cause a measurable change in soil aggregation in a short period of time, two years in this study,” says Tomlinson.

    “There were few instances where the species or mixture of species influenced the results,” he continues. “Rather, the presence of cover crops in the conservation systems appears to have a more dominant role. The significance of this work is that it demonstrated there can be measurable changes in some dynamic soil properties in the short term (two years). This is within a system that involves a reduction in tillage operations and the addition of cover crops.”

    “We conclude that the use of less tillage and a cover crop in a conservation system is generally beneficial as compared to a conventional system. This study illustrates the potential for improving some soil health parameters in as little as two years,” says Tomlinson. Future research will focus on how the implementation of conservation system across a range of agricultural systems and time scales effect dynamic soil properties.”

    Funding for this research was provided by NRCS Conservation Innovation Grant.

    Cathryn Davis measuring infiltration rates in an oat cover crop during her MS research published in this paper (photo by DeAnn R. Presley)

  • Research Helps Develop High-Yielding, Drought Tolerant Lines of Chickpea

    Chickpeas are a very important crop and food in India. They are used almost every day in meals and snacks. India is the largest producer, consumer, and importer of chickpeas. And with good reason — they are high in protein, fiber, and vitamins and minerals.

    While India grows about 12 million tons of chickpeas each year, the national yield of the crop has not increased much over time. However, the need for more chickpeas to feed the increasing population continues to grow.

    This is why a group of researchers across several research institutions in India are working to develop high yielding chickpea varieties. The team recently reported their results in The Plant Genome.

    “High yielding varieties will help small-holder farmers by delivering more produce with an option to increase income,” says Rajeev Varshney, member of the Crop Science Society of America. “It is important to develop better varieties that are tolerant to drought and are able to meet the demand.”

    Rajeev Varshney, a research program director at the International Crops Research Institute for the Semi-Arid Tropics, examines a chickpea crop (Credit: ICRISAT)

    Over time, chickpea production has moved from northern India to the central and southern parts of the country, where there is less water. This is in addition to climate change impacting global agriculture.

    Varshney and his collaborators set out to breed new varieties of chickpeas with drought tolerance and higher yields. They used genetic techniques to breed several traits for drought tolerance. They focused on popular chickpea varieties already grown by farmers.

    The team used a common method called introgression, where a popular variety is crossed with a variety with the desired traits. Following a series of evaluations and repeated crossings, the breeders arrived at an improved chickpea variety with the desired traits.

    “However, this conventional process is not very precise, and in this procedure, breeders need to screen a large number of plants in field conditions,” Varshney explains. “For example, if there is a lot of rain in that season, breeders cannot select the line for drought tolerance. It ruins the whole experiment.”

    To combat this, the researchers used a technique called marker-assisted backcrossing. It uses laboratory techniques to detect a genetic marker. Genetic markers are DNA segments associated with certain plant characteristics or agronomic traits desired by farmers.

    By being able to detect certain plant characteristics in the lab using genetic markers, there is no need to do lots of testing every year in the field. It makes the breeding process precise, fast, and cost-effective.

    The work helped incorporate drought tolerance into three popular varieties of chickpeas. Overall, researchers developed six lines of chickpea with higher yields under drought conditions. One line, Pusa Chickpea 10216, has been released for use by Indian farmers.

    “We worked with already released elite varieties that are preferred by farmers,” Varshney says. “By improving these, it’s more likely they will be adopted by farmers in a faster manner.”

    “Here we have demonstrated successful use of using genetic markers to develop drought tolerant chickpea varieties,” Varshney says. “We would like to see this kind of breeding being deployed by our national partners at a large scale in India, Ethiopia, Kenya, Tanzania, and elsewhere.”

    This research shows the public benefits of this kind of genetic research. Maintaining strong public support and funding for the research pipeline allows such work to take place.

    “The work shows how genomics research can be used to develop better high-yielding drought tolerant varieties,” Varshney says.

    Rajeev Varshney is a research program director at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) and Adjunct Professor with Murdoch University (Australia). Support for this research was provided by the Government of India through its Department of Biotechnology in the Ministry of Science and Technology, Department of Agriculture, Cooperation & Farmers Welfare in the Ministry of Agriculture & Farmers Welfare, and the Bill & Melinda Gates Foundation.

    Flowers are incredibly striking when in full bloom (Photo by L. Vidyasagar)

    American Society of Agronomy, Soil Science Society of America, Crop Science Society of America: Collectively, these Societies represent more than 12,000 individual members around the world. Members are researchers and professionals in the areas of growing our world’s food supply while protecting our environment. Together we work toward solutions to advance scientific knowledge in the areas of agronomy, crop science, and soil science.

    Twitter: @ASA_CSSA_SSSA & @SSSA_soils | Facebook: ASA, CSSA & SSSA | Instagram: @sustainablefoodsupply & @iheartsoil

  • How do Radishes Work as a Cover Crop?

    Farmers love tools. The prospect of a fully stocked tool shed ranges from badge of honor to true obsession.  Plants, too, can be used as tools. Integrating cover crops into a farmer’s toolbox can offer many benefits – and it’s a tool given to us by nature!

    Getting farmers to adopt cover crops as various tools can be hard. To do that, we need to better understand these different tools and their uses. Cover crops like clover add nitrogen to the soil, while reducing erosion and runoff. And, radishes, a tasty ingredient in salad, can be used to break up soil and other hard jobs.

    Breaking up soil with radishes

    Millennia ago, Greek philosophers presented the Doctrine of Signatures, stating that a plant’s appearance may resemble its practical use. For example, walnuts were linked to brain health and beans to kidneys. In thinking about the radish as a tool, the plant root could be similarly equated to the drill, a type of natural tilling.

    Thick radish roots are an ideal choice for natural drilling into the soil to reduce compaction. When the radish crops are terminated, the radish and roots leave large, open pores in the soil. This increases soil aeration and water infiltration. Along with this comes more earthworm and microbial activity. It’s clear that a tillage radish cover crop certainly lives up to that name. As it turns out, the simple radish can be quite the complex tool when properly utilized.

    Scavenging and cleanup

    There are many varieties of radish. From ‘Daikon’ to ‘Icicle’, knowing the specific cultivar is an important part of deciding if a radish belongs in your field or on your plate! When an agronomist recommends a radish variety for use as a cover crop, they have a job in mind to make use of these unique plant features.

    Farmers turn to “scavenging” to optimize chemical inputs and yield outputs by using cover crops. The cylindrical roots of the radish grow deep and capture soil nutrients that were intended for the preceding cash crop.

    Many varieties are uniquely suited for this task, having been bred specifically for deep taproots that extend several inches or even feet deeper than their thick quintessential core. By scavenging nutrients from soil layers that are the hardest for most crop roots to access, radishes can be used to target critical areas to keep nutrients from the groundwater table. Though picky eaters may leave behind a harvested radish on their plate, the radish itself helps ensure that as little as possible goes to waste in terms of subsoil nutrients.

    A Daikon radish cover crop emerges after being seeded into standing corn. Radishes help break up soil compaction and use up extra nutrients to reduce runoff. Credit: Ivan Dozier

    Biofumigation – natural chemical combatants

    In March 1990, Former President George HW Bush personified picky eaters everywhere when he issued the proclamation: “I’m not going to eat any more broccoli!” The president succeeded in banning the brassica from Air Force One and the White House.

    The same pungent flavor that the former President didn’t like is loved by many. And its special compounds called gluconsinolates that give them their flavor. These compounds contain sulfur (like some medicines) and can also act as natural pesticides in the soil, a method known as “biofumigation.” These compounds can be a powerful deterrent to insects and even some species of fungi.

    The choice depends on the job

    When choosing a radish and/or any other cover crop, the most important consideration is to select the right tool for the job! For example, planting a radish in a poorly drained clay soil can drastically restrict the root growth necessary for several of the benefits. Selecting the wrong cover crop is like trying to tighten a bolt with a hammer instead of a wrench, which may explain why some don’t see convincing results.

    When choosing a radish for cover cropping, agronomists recommend that farmers select the right tool (specie) for the right job. Shown, a selection of cover crop radishes with roots. Credit: T&T Seeds

    Successful cover croppers often strengthen their polyculture by adding the radish into a multi-species mix. For those looking for a natural multi-tool to alleviate compaction, scavenge subsoil nutrients, and ward away pests, I can assure you that radishes will not leave you with a bitter taste! — By Ivan A. Dozier, CCA, Product Manager for Agronomy & Analytics at IntelinAir (American Society of Agronomy and Crop Science Society of America)

  • New Dry Beans from UC Davis Combine Qualities for Both Farmers & Consumers

    Beans in the UC Davis breeding program, whose varieties have been selected to combine excellent culinary with improved yields and resistance to bean common mosaic virus. Credit: Travis Parker

    Plant breeders are constantly working to develop new bean varieties to meet the needs and desires of the food industry. But not everyone wants the same thing.

    Many consumers desire heirloom-type beans, which have great culinary quality and are visually appealing. On the other hand, farmers desire beans with better disease resistance and higher yield potential.

    The bean varieties that farmers want to grow are sometimes different than the varieties consumers want to purchase. Until now.

    Travis Parker, a plant scientist at University of California, Davis, has worked with a team of researchers to release five new varieties of dry beans that combine the most desirable traits.

    The new varieties, UC Sunrise, UC Southwest Red, UC Tiger’s Eye, UC Rio Zape, and UC Southwest Gold, were recently highlighted in the Journal of Plant Registrations, a publication of the Crop Science Society of America.

    “Our new beans combine the best of both worlds for farmers and consumers,” says Parker. “They combine the better qualities of heirloom-type beans with the better qualities of commercial types.”

    Heirloom-type beans often represent older bean types that are known for culinary qualities and seed patterns. These are highly desired by consumers. Heirloom types often fetch a higher market value than other beans.

    Commercial dry beans often have higher yields, shorter maturity times, and improved disease resistance. While they possess qualities desirable to producers, they don’t command as high of a market price compared to their heirloom counterparts.

    A comparison of the heirloom variety “Tiger’s Eye” (left, with virus symptoms) and the newly released “UC Tiger’s Eye” (right, healthy leaves). These varieties have similar culinary qualities, but UC Tiger’s Eye is resistant to the common mosaic virus and has higher yields. Credit: Travis Parker

    “Our goal was to improve field characteristics of the heirloom beans without losing culinary characteristics,” said Parker. “We have an interest in higher-value varieties and want them to grow well.”

    Farmers growing the heirloom dry beans often sell the beans to health-conscious consumers or high-end restaurants. This sale often leads to a higher price point. However, these beans are prone to disease and don’t perform well in the field.

    “We know that existing heirloom beans don’t usually do well in terms of yield,” said Parker. “Breeding beans for high yields is a major improvement for farmers. The new varieties are high-yielding, heat-tolerant, and are also resistant to bean common mosaic virus.”

    Incorporating disease resistance was essential when developing the new bean varieties. Bean common mosaic virus is a well-known problem that is hard to control in the field.

    “The only really effective means to handle the virus is through genetic resistance,” explains Parker.

    The new varieties, such as UC Sunrise, satisfy the need for farmers to have a bean that is disease resistant while also yielding 50% more than heirloom types. In addition, the beans do not take as long to grow between planting and harvest.

    UC Sunrise seeds Photo Caption: A detailed view of UC Sunrise, one of the new varieties of the heirloom-like dry bean. The colorful pattern is desirable to consumers. Credit: Travis Parker

    Commercial and heirloom beans come from the same species, but they are in different market classes. The heirloom varieties are bred with intimate knowledge of what tastes good and what works well in the kitchen.

    “In recent decades, there has been less attention paid to consumer desires during the bean breeding process,” says Parker. “There are more layers between the breeder and the consumer. We are trying to make sure to keep consumers in mind while incorporating qualities that are beneficial to the farmer.”

    With consumer desires in mind, the research team used cross-pollination to breed plants with key characteristics they selected. As Parker and the team continued the breeding process, they performed taste tests to ensure the beans met the level of culinary quality expected of an heirloom-type bean, in terms of flavor and visual appeal.

    This research was supported by the Clif Bar Family Foundation, Lundberg Family Farms, the United States Department of Agriculture Organic Agriculture Research & Extension Initiative, and the United States Department of Agriculture Western Sustainable Agriculture Research and Education program.

    To learn more about the research behind these new dry bean varieties, watch this video from Travis Parker.

  • Research Gives Possible Answers to Increase Pollinator Populations on Farms

    Many living creatures live in soil. Though their sizes range from microscopic soil microbes to larger animals like gopher turtles, they all call soil their “home.” Included in these ground-dwelling species are bees – vital in the pollination cycle of about 90% of plant life.

    Rebecca Lybrand and her team at Oregon State University are studying the interaction between the bees and soil in agricultural settings.

    According to the recently-published paper, bees contribute $15 billion to crop value annually. They pollinate about three-quarters of the fruits, vegetables, and nuts within the United States alone. Declines in honeybee colonies are a critical threat to agriculture and the global food supply.

    “Growers who are interested in attracting alternative pollinators, such as wild bees, face a major challenge,” says Lybrand. “There are not many studies about what habitats are best for these wild bees.”

    Pollinators are widely affected by human land use. Creating buildings, parking lots and other “anthropogenic changes” disrupt the natural habitats of animals and plants. Agricultural disturbance also affects bee communities. Interestingly, above-ground bee species are nine times more affected by agricultural intensification than ground-dwelling species.

    In some cases, growers have been able to build “bee beds” in their farm setting. In the 1950s, they started to design moist, salty soil areas to attract ground-nesting bees that helped increase alfalfa yields in Washington state.

    Lybrand’s study looked at physical and chemical properties of soils collected from active bee and sand nest wasp sites in the Willamette Valley of western Oregon. They compared soil properties among seven farm sites to identify similarities and differences.

    The Willamette Valley has wet winters with warm, hot summers. The team first found agricultural sites that contained ground-nesting bees. They collaborated with farmers who observed ground-nesting bee activity around their fields.

    The nests are only identified by rather small holes (only 3-5mm). The team only collected data if they observed bees entering the nest. Nests and holes can remain even after the bees leave. At the study site, they specified the type of bee to the family level (i.e. “bee” versus “genus” and “species”.) But they also collected some bees to bring back to the lab for further identification.

    The data the team collected in the field included soil temperature, pH, and soil texture. They also collected soil samples to bring back to the lab for analysis.

    Findings from the study included that active nesting sites were present in locations with little to no rock cover and low vegetation. Nesting sites were found in areas with low organic matter coverage. The slope of the land didn’t seem to have any influence, nor did a north/south-facing aspect.

    “One of our observations confirmed that active emergence holes remained open throughout the year,” says Lybrand. “They didn’t swell shut during the wetter, cooler seasons – despite having clay in the soils that might cause shrinking and swelling.”

    An interesting finding from the research is that the team found lipids in the soil nest linings. The lipids may provide a type of waterproofing for the nests and their inhabitants.

    “Because the large majority of wild bee species nest in the soil, studies about how to best attract them to farms are important,” says Lybrand. “Soil scientists and entomologists can partner with growers to identify soil habitats that support and attract more of these pollinators to agricultural lands. Improving our understanding of the connections between agriculture and the soils that bees, crops, and living organisms rely on to survive is important. Our research also provided a framework for studying ground-nesting organisms – an area of soil science that is underrepresented.”

    Looking to the future, Lybrand says, “future research should also integrate methods that identify bees and/or wasps to the species level. That would allow for interpretations of the results from an ecological point of view. Another question to follow up on could be the nature and purpose of the lipids found in the soil nest linings, to confirm their actual role.”

    This research was published in Soil Science Society of America Journal. Funding for this project came from an Agricultural Research Foundation grant via Oregon State University.

    American Society of Agronomy, Soil Science Society of America, Crop Science Society of America: Collectively, these Societies represent more than 12,000 individual members around the world. The scientists’ memberships build collaborating partnerships in the agronomy, crops, and soils science fields for the advancement of knowledge.

  • Research Gives Possible Answers to Increase Pollinator Populations on Farms

    Many living creatures live in soil. Though their sizes range from microscopic soil microbes to larger animals like gopher turtles, they all call soil their “home.” Included in these ground-dwelling species are bees – vital in the pollination cycle of about 90% of plant life.

    Rebecca Lybrand and her team at Oregon State University are studying the interaction between the bees and soil in agricultural settings.

    According to the recently-published paper, bees contribute $15 billion to crop value annually. They pollinate about three-quarters of the fruits, vegetables, and nuts within the United States alone. Declines in honeybee colonies are a critical threat to agriculture and the global food supply.

    “Growers who are interested in attracting alternative pollinators, such as wild bees, face a major challenge,” says Lybrand. “There are not many studies about what habitats are best for these wild bees.”

    Pollinators are widely affected by human land use. Creating buildings, parking lots and other “anthropogenic changes” disrupt the natural habitats of animals and plants. Agricultural disturbance also affects bee communities. Interestingly, above-ground bee species are nine times more affected by agricultural intensification than ground-dwelling species.

    In some cases, growers have been able to build “bee beds” in their farm setting. In the 1950s, they started to design moist, salty soil areas to attract ground-nesting bees that helped increase alfalfa yields in Washington state.

    Lybrand’s study looked at physical and chemical properties of soils collected from active bee and sand nest wasp sites in the Willamette Valley of western Oregon. They compared soil properties among seven farm sites to identify similarities and differences.

    The Willamette Valley has wet winters with warm, hot summers. The team first found agricultural sites that contained ground-nesting bees. They collaborated with farmers who observed ground-nesting bee activity around their fields.

    The nests are only identified by rather small holes (only 3-5mm). The team only collected data if they observed bees entering the nest. Nests and holes can remain even after the bees leave. At the study site, they specified the type of bee to the family level (i.e. “bee” versus “genus” and “species”.) But they also collected some bees to bring back to the lab for further identification.

    The data the team collected in the field included soil temperature, pH, and soil texture. They also collected soil samples to bring back to the lab for analysis.

    Findings from the study included that active nesting sites were present in locations with little to no rock cover and low vegetation. Nesting sites were found in areas with low organic matter coverage. The slope of the land didn’t seem to have any influence, nor did a north/south-facing aspect.

    “One of our observations confirmed that active emergence holes remained open throughout the year,” says Lybrand. “They didn’t swell shut during the wetter, cooler seasons – despite having clay in the soils that might cause shrinking and swelling.”

    An interesting finding from the research is that the team found lipids in the soil nest linings. The lipids may provide a type of waterproofing for the nests and their inhabitants.

    “Because the large majority of wild bee species nest in the soil, studies about how to best attract them to farms are important,” says Lybrand. “Soil scientists and entomologists can partner with growers to identify soil habitats that support and attract more of these pollinators to agricultural lands. Improving our understanding of the connections between agriculture and the soils that bees, crops, and living organisms rely on to survive is important. Our research also provided a framework for studying ground-nesting organisms – an area of soil science that is underrepresented.”

    Looking to the future, Lybrand says, “future research should also integrate methods that identify bees and/or wasps to the species level. That would allow for interpretations of the results from an ecological point of view. Another question to follow up on could be the nature and purpose of the lipids found in the soil nest linings, to confirm their actual role.”

    This research was published in Soil Science Society of America Journal. Funding for this project came from an Agricultural Research Foundation grant via Oregon State University.

    American Society of Agronomy, Soil Science Society of America, Crop Science Society of America: Collectively, these Societies represent more than 12,000 individual members around the world. The scientists’ memberships build collaborating partnerships in the agronomy, crops, and soils science fields for the advancement of knowledge.