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How to Reduce Transplant Shock on Your Farm

Monday-Motivation-Photo_4-24-2017

Avoiding transplant shock: An open show transplanter in use as the crew sets out cabbage in the field.

Avoiding transplant shock when transplanting starters from the greenhouse to the field is a key sustainable farming method.

The time of year has once again arrived when we will be taking plants out of the greenhouse and transplanting them into the field. This can be one of the most stressful experiences plants undergo as they are taken from the warm and sheltered environment of the greenhouse and placed into a field where they are at the mercy of the elements. Plants will almost always incur some amount of damage to their roots as well as their leaves during this process. All of these various stresses are grouped under the general name of “transplant shock.” If plants undergo too much transplant shock, it can leave them open to disease, pest pressure, and lower yield potential. But what can we do to help our plants through this period of increased stress?

Transplant shock is really the sum of all the stresses plants experience during the move from flat to field. In order to look at how we can help the plant through this time, we’ll divide these stresses into three different categories: environmental changes, physical damage, and nutritional deficiencies.

Most farmers help their plants acclimatize to these moisture and temperature changes by putting them through a period of  “hardening  off,”  especially in the spring. This is done by taking the crop out of the greenhouse and placing it in a new location where the plant is exposed to air movement and greater temperature changes, but is still sheltered from weather extremes. This can be accomplished by locating the plants in an area where they are open to moderate breezes and lower daytime temperatures, but can be covered to shelter them from strong winds or nighttime frosts. This limited exposure signals them to strengthen their main growing stalks to cope with wind and change the  chemistry of their leaves in order to withstand the lower temperatures.

To help transplants acclimatize to changes in soil temperature and biology and avoid transplant shock, there are several things we can do. The use of black plastic mulch in the field will warm the soil and is especially useful when it comes to cucurbits and solanaceous crops as it assists with weed control. Putting molasses into the transplant water can help too, as this will stimulate soil biology which in turn will raise the soil temperature.

The second and third categories of transplant stress, physical damage and nutrient deficiencies, are closely linked. Physical damage is unavoidable to a certain degree when transplanting. Care should be taken to avoid breaking any leaves or causing bruising as these injuries can become vectors for disease. The roots, however, not the upper part of the plant, often sustain the most damage during transplantation. Roots uptake nutrients mainly through their delicate root hairs and their growing tips, both of which are very susceptible to damage. This can lead to the plant experiencing a nutrient deficiency shortly after transplant due to its decreased uptake ability. This nutrient deficiency occurs at the same time the plant is trying to regenerate its root system and adjust to its new environment. This type of root damage can also happen easily with bare root transplants because in the process of removing the soil from the roots, more of the fragile root hairs can be damaged than when the transplants are in plug form.

A broccoli plant in the greenhouse. This plant shows no signs of nutrient deficiency

A broccoli plant in the greenhouse. This
plant shows no signs of nutrient deficiency

Reducing Transplant ShockAiding Plants To Avoid Transplant Shock

Helping the plant through the transplant stress is essential and can be accomplished a number of different ways. One way is to stimulate the plant to grow with natural growth hormones. Another is to provide the plant with a supply of easily absorbable macro- and micronutrients. Kelp is an excellent source of natural growth hormones and micronutrients. During transplantation a liquid kelp extract works best as it can easily  be added to water. It is also important to address macronutrients including phosphorus, calcium, potassium and nitrogen. All of these nutrients are involved in the formation of new tissue, and giving your plant an available supply of these nutrients will help it repair damage at a faster pace.

It is important to make sure that your plant is not already deficient in these nutrients before they go into the field.   It is surprising how many plants have some phosphorus deficiency, noticeable by a purpling of the leaves, or a nitrogen deficiency, noticeable by yellowing or chlorotic growth, before going into the field. Plants deficient at transplant are at a further disadvantage since they are already struggling to make up for these nutrients as well as trying to repair damage. Make sure that you are using high quality potting mix for  your seedlings to avoid this problem. Even with a good potting mix plants can become stressed, and it may be necessary to top dress the flats with a compost mix or fertilizer or you can inject liquid fertilizers into the for their needs. Special attention should be paid to plants that are past their ideal transplant date. Look for the noticeable signs of deficiency, and keep your plants well supplied with nutrition.

One of the best ways to decrease transplant shock is to supply extra nutrients and biostimulants at the time of transplant.  There are several ways to accomplish this. One is to drench the plants while they are still in their flats. This can be done by mixing a large dose of nutrients into the final watering, or by mixing up a batch of “transplant soup” in a bin and submerging the flats in the solution until the soil is saturated. It is okay to have some of the “soup” get on the foliage of the plant as this will simply act as a foliar feeding. When dealing with bare-root transplants soaking the roots of the plants in a weak solution can be done instead. Another way to deliver this “soup” is to mix it into the transplant water. This works well, but depending on the transplanter, it can leave a lot  of  the solution in between the plants where it is not as effective. However it will help to stimulate soil biology, especially if molasses is used in the solution. Using the two systems of drenching flats and adding products to the transplant water works well, as it both provides the nutrition your plants need and stimulates soil life.

Transplanting is a very stressful time for the plants.  They are put into conditions very different than what they are used to and are exposed to a wide range of stresses they have not encountered previously. The plants can also suffer damage during transplantation, especially to the root system, and this can lead to a period of nutrient deficiency as the plant tries to repair itself and as its ability to find nutrients has been decreased. All of these setbacks can weaken the plant and open it to disease and pest pressures, as well as decrease overall yield potential. By using conscientious cultural practices, stimulating root growth and soil life and giving the plant easily available forms of nutrients, we can help our plants pull through transplant shock faster. This in turn can lead to an increase in our plants’ ability to fend off disease and pests and result in improved yields.

Allen Philo has worked as the field  operations manager on a large organic vegetable farm, and is  currently the specialty  crop  consultant  for Midwestern Bio-Ag. He can be reached at allenp@midwesternbioag.com.

This article appeared in the April 2012 issue of Acres U.S.A.

by Allen Philo

Harnessing the Power of Clay

by JAMES C. SILVERTHORNE

One of my horses, an 8-yeaphoto1r-old mare, came in from the pasture walking with a distinct limp. I found that she had a horizontal cut (three-eighths of an inch deep by 1¾ inches long) on the fleshy back of her left foreleg’s pastern, just above the bulbs of the heel. An equine veterinarian inspected the wound and advised me that healing would be slow due to the wound site’s new tissue being flexed with each step. He also assured me that after healing, the previously able animal would always be lame from scar tissue forming too close to a tendon.

Swelling soon occurred on the leg from the wound up to the knee joint. Periodically, I support-wrapped the leg from fetlock (joint just above pastern) up to the knee with elastic banding cloth. The cut began to heal with applications of a comfrey gel, but after a week the new tissue cracked open because of November’s change to colder, drier air. Healing stopped. Later, I realized that applications of a moisturizing salve had been needed.

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What is Humus & How is it Formed?

Secrets of Fertile SoilsExcerpt from Secrets of Fertile Soils: Humus as the Guardian of the Fundamentals of Natural Life by Erhard Hennig, published by Acres U.S.A.

by Erhard Hennig

Humus forms as a result of the complicated interplay of inorganic conversions and the life processes of the microbes and tiny creatures living in the soil. Earthworms play a particularly important role in this process. Humus formation is carried out in two steps. First, the organic substance and the soil minerals disintegrate. Next, totally new combinations of these break down products develop, which leads to the initial stages of humus. Humus formation is a biological process. Only 4-12 inches (10-30 centimeters) of humus-containing soil are available in the upper earth crust. This thin earth layer is all that exists to provide nutrition to all human life. The destiny of mankind depends on these 12 inches!

Cultivated soils with 2 percent humus content are today considered high-quality farmland. What makes up the remaining 98 percent? Depending on the soil type, soil organisms constitute about 8 percent, the remains of plants and animals about 5 percent, and air and water around 15 percent.

The remaining 70 percent of soil mass is thus of purely mineral origin. The mineral part of the soil results from decomposition and the erosion of rock. The dissolution of these components is carried out by the lithobionts, which can be seen as the mediators between stone and life. It was Raoul H. Francé who coined the term “lithobiont,” which means “those who live on stone.” The lithobionts are the group of microbes that begin the formation of humus. They produce a life-giving substance from the nonliving mineral. On the basis of this process, living matter, earth, plants, animals and human beings can begin, step by step, to build.

Only soils with an optimal structural state of tilth have a humus content of 8-10 percent. Untouched soils in primeval forests can, at best, reach 20 percent. A tropical jungle can’t use up all its organic waste, so humus can be stored. All forests accumulate humus, but real humus stores only emerge over the course of millennia. Once upon a time accumulations of humus known as chernozem (Russian for black earth) could be found in the Ukraine.

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Soil Ecosystems: Maintaining Critical Microbial Life

earthworm soil life.tifSoil ecosystems aren’t always the first things people notice when they are in nature.

When asked to describe a forest or a meadow, most people would probably begin with the plants, the species diversity or the color of the foliage. They probably wouldn’t pay much attention to the soil ecosystems and the critical microbial life. But a new Yale-led study shows the importance of earthworms, beetles and other tiny creatures to the structure of grasslands and the valuable soil ecosystem services they provide.

During a 3-year study, researchers found that removing these small animals from the soil of a replicated Scottish sheep meadow altered the plant species that grew in the ecosystem, reduced overall productivity and produced plants that were less responsive to common agricultural management, such as fertilization.

The results reflect the long-term ecological impacts of land use changes, such as the conversion of forests to agricultural land, researchers say.

“We know these soil animals are important controls on processes which cause nutrients and carbon to cycle in ecosystems, but there was little evidence that human-induced loss of these animals has effects at the level of the whole ecosystem on services such as agricultural yield,” said Mark Bradford, lead author of the study published in the Proceedings of the National Academy of Sciences.

This article appears in the December 2014 issue of Acres U.S.A.

Soil Ecosystems: Nutrient Additions

New research from Iowa State University shows that agricultural inputs such as nitrogen and phosphorus alter soil microbial communities and soil ecosystems. Adding nitrogen and phosphorus fertilizers, commonly used as fertilizers, to the soil shifts the natural communities of fungi, bacteria and microscopic organisms called archaea that live in the soil, said Kirsten Hofmockel, associate professor.

Hofmockel and other scientists associated with the Nutrient Network, a global group of scientists, revealed that microbial community responses to fertilizer inputs were globally consistent and reflected plan responses to the inputs. Many soil microbes perform helpful functions in the native ecosystems and altering those microbial communities may have negative environmental consequences, Hofmockel said. The researchers found nutrient additions favored fast-growing bacteria and decreased the abundance of fungi that share a symbiotic relationships with grassland plants.

This encapsulation of the research is from the December 2015 issue of Acres U.S.A.

Soil Ecosystems: Synthetic Nitrogen Lingers for Decades

Nitrogen fertilizer applied to crops lingers in the soil ecosystems and leaks out as nitrate for decades towards groundwater — “much longer than previously thought,” scientists in France and at the University of Calgary say in a new study.

Thirty years after synthetic nitrogen (N) fertilizer had been applied to crops in 1982, about 15 percent of the fertilizer N still remained in soil organic matter, the scientists found.

After three decades, approximately 10 percent of the fertilizer N had seeped through the soil ecosystem toward the groundwater and will continue to leak in low amounts for at least another 50 years.

The findings show that losses of fertilizer N toward the groundwater occur at low rates but over many decades, says Bernhard Mayer, U of C professor of geochemistry and head of the Applied Geochemistry Group.

That means it could take longer than previously thought to reduce nitrate contamination in groundwater, including in aquifers that supply drinking water in North America and elsewhere, he says.

“There’s a lot of fertilizer nitrogen that has accumulated in agricultural soils over the last few decades which will continue to leak as nitrate towards groundwater,” Mayer says.

Canada and the United States regulate the amount of nitrate allowed in drinking water. In the 1980s, surveys by the U.S. Environmental Protection Agency and the U.S. Geological Survey showed that nitrate contamination had probably impacted more public and domestic water supply wells in the United States than any other contaminant.

The study, “Long-term fate of nitrate fertilizer in agricultural soils,” was published in the Proceedings of the National Academy of Sciences.

This summary appears in the December 2013 issue of Acres U.S.A.