soil

The best time to submit a soil sample

Article by Joseph Croze

soil samples in boxes along a bookshelf in the UConn Soil Nutrient Analysis Lab on the Depot Campus
Soil samples waiting for analysis at UConn. Photo: Joseph Croze

As most of you are probably already familiar with, the University of Connecticut is home to the UConn Soil Nutrient Analysis Laboratory. This lab is staffed by Dawn Pettinelli, the manager, and myself, the technician. We also have a few part time and student employees throughout the year that help with the receiving, spreading, and sieving of soil samples; among other things. We offer an array of tests designed to help homeowners, community gardeners, farmers, etc… maximize the efficiency of their soil to produce the greatest yields in whatever plant or crop they are growing, from silage corn to turf. We can test for soil organic matter content, textural fractionation, soluble salts, Nitrogen, and Carbon. We also provide tests for plant tissues and corn stalks. However, our most vital and popular test is the Standard Nutrient Analysis. This is a relatively comprehensive test that allows us to make limestone and fertilizer recommendations. We check the pH, add a buffering agent and then retest the pH. From there we are able to determine the soils capacity to resist the change in pH, this allows us to make an accurate and precise limestone recommendation, in lbs/1000 square feet, or lbs/acre, depending on the desired crop production. The second part of the Standard Nutrient Analysis is the actual nutrient content. Soil samples are analyzed for micro and macro nutrients; Potassium, Calcium, Phosphorus, Magnesium, Aluminum, Boron, Copper, Iron, Manganese, Zinc, and Sulfur. Samples are also screened for Lead. Using the nutrient results, we are able to make fertilizer recommendations based on what is being grown. We give results in N-P-K format, and also provide organic alternatives.

We get calls year round from customers asking if they can submit a soil sample, and the answer is always yes! You can submit a soil sample any time of the year, we receive soils from throughout the country (although we have to be careful of areas under certain quarantines). Generally, it only takes around a week from when we receive a sample for us to send out the results. As you might imagine, Spring is an extreme exception. We are so busy and backed up with thousands of soil samples right now, we are expecting a 3 week turn-around time. We understand that everyone is eager to get their hands dirty and work on their lawns and gardens, but waiting until Spring to submit soil samples isn’t the best idea.

Continue reading….

Spotlight – Soil Degradation

One of the most pressing resource related issues around the world is the continual reduction in the percentage of arable land. Currently, 37% of land worldwide is considered agricultural, only 10% is deemed arable, or plowable, and suitable for crop production (World Bank Group, 2015). The shrinking percentage of suitable farm land is a direct result of soil degradation, which is attributed to tillage practices and the use of agrochemicals in intensive agriculture. Overgrazing of rangelands, natural occurrences such as wildfires, and non-agricultural human activities such as road salt applications also contribute to the degradation of soils, making mediation efforts cumbersome. Although the degradation of soils is a multifaceted process with a range of negative effects, effects tend to be closely tied with one another making the process as a whole degenerative.
 

The current intensive agricultural systems in place throughout the world aim to maximize production through increased inputs, such as labor and agrochemicals, while reducing waiting periods between crops. Large-scale annual crop production relies primarily on conventional tillage methods such as the moldboard plow, an implement that cuts a furrow slice of soil (around 8 inches in depth). The furrow slice is lifted, flipped, and dropped back down, inverting the soil profile. Simultaneously, this implement forms a hardpan layer of compacted soil beneath the disturbed portion. Both the inversions and hardpans negatively impact the soil’s structure. A compromised soil structure carries its own concerns and at the same time predicates multiple downstream effects.

A soil’s structure refers to the arrangement of fine soil articles into groups called aggregates. Many soil activities such as water movement, heat transfer, and aeration are directly impacted by the formation and arrangement of aggregates which results from a range of slow biological, physical and chemical processes. Aggregates are delicate and become destroyed in frequently disturbed soils such as those in annual cropping systems. Destruction of aggregates increases the bulk density of a soil. As bulk density increases water infiltration, water holding capacity, aeration, and root penetration decrease, making it more difficult for crops to access resources essential for growth.

The regular application of agrochemicals in cropping systems further diminishes the health of soil. Agrochemicals include herbicides, pesticides, fertilizers, and other soil amendments. One of the main concerns with the addition of these chemicals is their interaction with soil organisms. Soil macro- and microorganisms include bacteria, fungi, and earthworms; all contribute to a healthy plant rhizosphere and provide a range of benefits within cropping systems. These organisms are very sensitive to variation in their environment such as changes in pH, salinity, and the carbon:nitrogen ratio. These inputs represent rapid cyclic environmental shifts to which soil organisms cannot acclimate or adapt to. Instead, the diversity of soil organism diversity is diminished.

Soil organisms play a range of roles in the development and maintenance of a healthy soil profile, which in turn affects the growth and development of crops. Microorganisms such as bacteria fix nitrogen, making the largely inaccessible pool of atmospheric nitrogen available for plant uptake. Fungi, like mycorrhizae, form mutualistic associations with plant roots, extending their network of nutrient and water uptake. Larger organisms such as earthworms help to form soil aggregates by creating macropores and producing worm castings. Many insects also contribute to the formation of soil aggregates as well as help reduce the weed seedbank via predation. Healthy, natural soil systems are engineered by a consortium of organisms and by design are able to provide the needs of plants. However, in some cropping systems, this level of provision is deemed inadequate, prompting the need for agrochemicals and at the same time impacting the functionality of the soil.

Soil degradation is not limited to artificial systems. There are several factors, both natural and human induced, contributing to the percentage of degraded land around the world, outside of agricultural systems. Wild fires, which occur regularly in arid regions, burn vegetation which help to hold soils in place. Climate change, combined with lack of management in fire-prone areas, has dramatically increased the frequency and intensity of these fires, increasing the potential erosion. Mismanagement and overgrazing of rangelands in dry regions also diminishes soil-stabilizing vegetation, creating the same potential for erosion. In more temperate regions, road salt application during the winter months has become cause for concern as these salts become distributed into the ecosystems affecting both soil structure and soil organisms.

The effects of soil degradation are not discrete, often tied to each other in a continuum in which some agricultural practices initiate a predictable sequence of events that ultimately leads to diminished soil health. Conventional tillage methods and the use of agrochemicals seem to be the catalytic events for such series of events in annual cropping systems; affecting soil structure, organic matter content, and the health of soil organisms. These in turn compromise the functionality of soils as the medium for crop growth and development. There is wealth of information on alternative practices that aim to reduce the impact of agriculture on soil health. For more information on soil conservation and alternative agricultural practices please visit the UConn Extension website or contact your local extension office.

Despite the evidence supporting the continual degradation of soils due to agricultural activities, there is little consideration for the viability of suggested remediation practices in regard to the effects on food production, farmers and the agriculture industry as a whole. Reducing tillage and agrochemical input is not a solution for many agricultural systems as some crops simply do not perform well in no till systems, while reduced agrochemical input would greatly compromise crop yields. Considering the importance of agriculture to society at large, farmers, who may be the most hardworking and underpaid individuals in the world, utilize available options to maintain soil health while still maintaining a productive and economically feasible operation.

From the farmers perspective, this is often represented by tradeoffs. Farmers are not ignorant to the concept of soil degradation or the importance of soil health. In fact, they understand the impact of these much better than anyone else. Operations which use agrochemicals and employ conventional tillage methods still take steps to maintain soil health. Many of these cropping systems utilize conservation practices such as the incorporation of cover crops or selection of organic agrochemical alternatives. Elizabeth Creech of NRCS (Natural Resources Conservation Service) wrote an informative piece entitled “The Dollars and Cents of Soil Health: A Farmer’s Perspective” which depicts many of the challenges farmers face when it comes to maintaining soil health. For more information please follow this link: https://www.usda.gov/media/blog/2018/03/12/dollars-and-cents-soil-health-farmers-perspective.

Nitrogen – The Fix

corn
Chlorotic corn. Image provided by T. Morris, 2018

Nitrogen is an essential nutrient required for the production and growth of all plants, vegetation, and living organisms. It makes up 78% of our atmosphere; however, that only accounts for 2% of the Nitrogen on our planet. The remaining 98% can be found within the Earth’s lithosphere; the crust and outer mantel. The Nitrogen found within the nonliving and living fractions of soil represents an unimaginably low fraction of a percentage of all the Nitrogen on our planet. That tiny percent of all total Nitrogen found in our soils is what we can interact with to help or hinder plant production.

To be considered an essential nutrient, an element must satisfy certain criteria:

  • Plants cannot complete their life cycles without it.
  • Its role must be specific and defined, with no other element being able to completely substitute for it.
  • It must be directly involved in the nutrition of the plant, meaning that it is a constituent of a metabolic pathway of an essential enzyme.

In plants, Nitrogen is necessary in the formation of amino acids, nucleic acids (DNA and RNA), proteins, chlorophyll, and coenzymes. Nitrogen gives plants their lush, green color while promoting succulent growth and hastens maturity. When plants do not receive adequate Nitrogen, the leaves and tissues develop chlorosis. However, over-application of Nitrogen can cause even more problems, including delayed maturity, higher disease indigence, lower tolerance to environmental stresses, reduced carbohydrate reserves, and poor root development.

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Don’t Be Too Eager to Work That Soil!

By: Penn State Extension

soilWorking soil that is too wet results in soil compaction. Learn how to test your soil to see whether it is too wet to till or plant.

As I write this, we’ve had some substantial rain lately, with more forecast in the near future.  This time of year, everyone is ready to put winter behind them, and turn the page to another growing season.  One of the first activities in the spring is tilling the soil for spring planting.  However, damage can be done rather quickly by getting into the fields when soil is too wet, causing soil compaction.

Soil compaction occurs when soil aggregates and particles are compressed into a smaller volume.  As soil is compacted, the amount of open pore, or void space, decreases and the density, or weight of the soil increases considerably.  Excessively compacted soil can result in problems such as poor root penetration, reduced internal soil drainage, reduced rainfall infiltration, and lack of soil aeration from larger macropores.  Most soil compaction occurs from machinery being driven over a field when conditions are too wet, and may lead to reduced yields of 10-20%.

To determine whether your soil is dry enough to work, a simple test can be performed.  Using a trowel or a spade, dig a small amount of soil and squeeze it in your hand.  Does the soil stick together in a ball or crumble apart?  Soil that crumbles through your fingers when squeezed is ready to till.  If, however, the soil forms a muddy ball and will not fall apart, give the soil another few days to dry, and sample again later.

If you suspect you may have soil compaction, a tool called a penetrometer may be able to help you determine your depth of soil compaction.  Based on the depth and severity of compaction, you will be able to identify corrective measures.  Some of these measures include deep tillage, and more recently, the use of cover crops.

For more information on soil compaction, see http://extension.psu.edu/agronomy-guide

International Year of Soils

soilThe U.S. Department of Agriculture kicked off its celebration of the International Year of Soils  to highlight the importance of healthy soils for food security, ecosystem functions and resilient farms and ranches.
“Healthy soil is the foundation that ensures working farms and ranches become more productive, resilient to climate change and better prepared to meet the challenges of the 21st century,” Agriculture Secretary Tom Vilsack said during an event at USDA headquarters. “We join the world in celebrating this living and life-giving resource.”
With an increasing global population, a shrinking agricultural land base, climate change, and extreme weather events the nations of the world are focusing their collective attention to the primary resource essential to food production—the soil. The United Nation’s Food and Agriculture Organization, working within the framework of the Global Soil Partnership, spearheaded the adoption of a resolution by the UN General Assembly designating 2015 as the International Year of Soils. The year of awareness aims to increase global understanding of the importance of soil for food security and essential ecosystem functions.
“Most people don’t realize that a diverse, complex, and life-giving ecosystem is right below our feet,” said Lisa Coverdale, State Conservationist for the Natural Resources Conservation Service (NRCS) in Connecticut. “NRCS is helping producers unlock the power of soil health as part of an important and very successful national campaign which demonstrates our renewed commitment to soil conservation and soil health.”
NRCS is coordinating activities to mark USDA’s involvement in the International Year of Soils. Nearly 80 years ago, NRCS (formerly the Soil Conservation Service) was created to improve the health and sustainability of our nation’s soils. The agency’s original mission continues to this day – providing assistance to producers looking to improve the health of the soil on their land. 
Conservation that works to improve soil health is one of the best tools NRCS has to help landowners face these impending challenges – and maintain and improve their productivity with the use of soil management systems that includes cover crops, conservation tillage, and no-till and crop rotations. These systems reduce sediment loss from farms; buffer the effects of drought, flood, and other severe weather; sequester carbon; and create biodiversity in our rural landscape.
“The International Year of Soils provides an opportunity for all of us to learn about the critical role soil conservation and improved soil health play in the economic and environmental sustainability of agriculture,” Coverdale said.
Working with the Soil Science Society of America and other partners, NRCS will be showcasing the importance of soil with monthly themes:
  •         January: Soils Sustain Life
  •         February: Soils Support Urban Life
  •         March: Soils Support Agriculture
  •         April: Soils Clean and Capture Water
  •         May: Soils Support Buildings/Infrastructure
  •         June: Soils Support Recreation
  •         July: Soils Are Living
  •         August: Soils Support Health
  •         September: Soils Protect the Natural Environment
  •         October: Soils and Products We Use
  •         November: Soils and Climate
  •        December: Soils, Culture, and People
To listen to the announcement made by Secretary of Agriculture Vilsack yesterday, or for more information about the International Year of Soil, visit the Connecticut NRCS soil health webpage.

World Soil Day

WSD_POSTER_ENToday is World Soil Day! Did you know? Soil is the basis for food, feed, fuel and fibre production and for services to ecosystems and human well-being. It is the reservoir for at least a quarter of global biodiversity, and therefore requires the same attention as above-ground biodiversity. Soils play a key role in the supply of clean water and resilience to floods and droughts. The largest store of terrestrial carbon is in the soil so that its preservation may contribute to climate change adaptation and mitigation. Soils also serve as a platform and source for construction and raw materials. The maintenance or enhancement of global soil resources is essential if humanity’s need for food, water, and energy security is to be met.

10 Tips for the November Gardener

mulchstrawberries-purdueTen Tips for the November Gardener:

1.  Once the ground has frozen (but before it snows), mulch fall planted perennials by placing 3 to 5 inches of pine needles, straw, chopped leaves around them.

2.  Continue to thoroughly water trees, shrubs, planting beds, lawn areas and recently planted evergreens until a hard frost. Plants should go into the winter well watered.

3. Remove any remaining fruit from fruit trees. Rake up and dispose of old leaves and debris to prevent insects and diseases from overwintering.

4.  Thoroughly clean bird feeders and fill them with birdseed. Clean birdbaths and consider a heating unit to provide fresh water throughout the winter.

5.  Cut back most perennials to 3-4 inches, but ornamental grasses, sedum, and hellebores can be left to provide winter interest.

6. Cover strawberry beds with an inch or so of straw once the ground freezes.

7. Pull stakes and plant supports. Clean them with a 10% bleach solution before storing for the winter.

8.  Protect grafted roses from winter damage by mounding 10-12 inches of soil around the base once the ground has frozen.

9. Trim existing asparagus foliage to the ground after the first hard frost and mulch beds.

10.  Pull annuals and add them to the compost pile. For annuals that self-seed, allow some seed-laden stems to remain in place.

 

For more information visit the UConn Home and Garden Education Center or call 877-486-6271.

 

Photo: Purdue Extension

Liming Soils

by Dawn Pettinelli, UConn Home & Garden Education Center

Grd limestoneAn incredible number of chemical, biochemical and biological reactions occur in our soils. Through these reactions, nutrients, whether already present in the soil or added by fertilizers, are changed into forms that can be taken up by plant roots. The pH of the soil affects all these reactions thereby determining the availability of nutrients essential for plant growth.

Soil pH is a measure of the acidity of the soil. A pH of 7.0 is neutral with measurements below this number reflecting acidity and those above indicating alkalinity. Many native soils have a pH in the range of 4.5 to 5.5 while most of our vegetables, flowers and turf grasses prefer it to be between 6.0 and 6.8. Some notable exceptions are blueberries and broad-leaved evergreens, like rhododendrons, which require acid soils.

When the soil pH falls below 6.0, nutrients like phosphorus, nitrogen and potassium become less available to plants. Acid soils are also typically deficient in magnesium and calcium, two important plant nutrients. Another problem with acid soils is that elements like aluminum are much more soluble and may be taken up in quantities that can harm plants. On the other hand, a pH that is greater than 7.5 can also render nutrients unavailable.

Limestone is the material of choice to raise a soil’s pH. It neutralizes soil acidity while also adding necessary calcium and magnesium. Dolomitic limestone, which contains both of these elements, is most widely available and usually recommended. If the magnesium level of your soil is above optimum, a calcitic limestone which is composed mostly of calcium compounds is called for.

Limestone can be purchased in several forms with ground, pelletized and hydrated being the most common. Economically, ground limestone is your best buy but some do not like the dusty mess encountered when applying. Pelletized limestone consists of pulverized limestone that is formed into little pellets. Both take about the same amount of time to react in the soil, anywhere from 3 to 9 months depending on conditions. Hydrated lime is fast-acting but quite caustic and only warranted under specialized circumstances. Its effects on pH, however, are short-lived. Wood ashes can also be used as a liming agent at one and a half times the rate of the recommended limestone application.

How much limestone to add depends on your soil’s present pH, the desired pH, as well as the amounts of clay and organic matter in your soil. A soil test can best determine recommended amounts. Very acidic soils may require several applications to bring the pH up to a suitable level. As a guideline, for every 100 square feet apply no more than 5 to 7 pounds of limestone to the surface or 10 pounds tilled to a depth of 6 inches at one time.  Once you’ve attained a desired pH, 5 pounds of limestone per 100 square feet every other year usually will maintain that level.

For those that don’t want to guess how much limestone to apply, consider a soil test. Fall is the perfect time to test because any limestone recommended and applied will have time to start affecting the soil pH before spring planting season and, you’ll be avoiding the spring rush!  For information on soil testing, liming soils or any other home and garden question, feel free to call the UConn Home and Garden Education Center, toll-free, at 877.486.6271, visit us on the web at http://www.ladybug.uconn.edu/ or contact your local UConn Extension Office.