adroll_adv_id = "RK545AVNKVEJFFRYPAE7DC"; adroll_pix_id = "T5DEBSDHVFG4FA3KSLHHKJ"; adroll_version = "2.0"; adroll_current_page = "other"; adroll_currency = "USD"; adroll_language = "en_US";
  • Privacy Trees
    • Thuja Green Giant
    • Leyland Cypress
    • Emerald Green Arborvitae
  • Evergreen Trees
    • Column 1
      • Arborvitae Trees
      • Cedar Trees
      • Cryptomeria Trees
      • Cypress Trees
      • Fir Trees
    • Column 2
      • Holly Trees
      • Juniper Trees
      • Pine Trees
      • Spruce Trees
      • Thuja Trees
  • Shade Trees
    • Column 1
      • Birch Trees
      • Japanese Maple Trees
      • Maple Trees
      • Willow Trees
    • Column 2
      • Oak Trees
      • Poplar Trees
      • Sycamore Trees
      • Other Shade Trees
  • Flowering Trees
    • Column 1
      • Crape Myrtle Trees
      • Dogwood Trees
      • Flowering Cherry Trees
      • Flowering Pear Trees
    • Column 2
      • Flowering Plum Trees
      • Magnolia Trees
      • Redbud Trees
      • Other Flowering Trees
  • Fruit Trees
  • Shrubs And Hedges
    • Column 1
      • Barberry
      • Boxwood
      • Butterfly Bush
      • Cherry Laurels
      • Encore Azaleas
      • Gardenias
    • Column 2
      • Hydrangeas
      • Knockout Roses
      • Lilacs
      • Rhododendrons
      • Wisteria
      • Other Shrubs & Hedges
  • Houseplants
    • Palm Trees
    • Tropicals

Order Online or Call Us Toll-Free at: 888-329-0140

Login

Login
$0.00
No products in the cart
Go to shop
Contact Us
My Growing Zone
What's my Growing Zone?
Enter your Zip Code below:
LOWEST PRICES ONLINE
Guaranteed! Show us a lower
price and we'll match it!
The Tree Center
paypal
FREE SHIPPING OVER $100
Orders typically ship the
very next business day
  • Privacy Trees
    • Thuja Green Giant
    • Leyland Cypress
    • Emerald Green Arborvitae
  • Evergreen Trees
    • Column 1
      • Arborvitae Trees
      • Cedar Trees
      • Cryptomeria Trees
      • Cypress Trees
      • Fir Trees
    • Column 2
      • Holly Trees
      • Juniper Trees
      • Pine Trees
      • Spruce Trees
      • Thuja Trees
  • Shade Trees
    • Column 1
      • Birch Trees
      • Japanese Maple Trees
      • Maple Trees
      • Willow Trees
    • Column 2
      • Oak Trees
      • Poplar Trees
      • Sycamore Trees
      • Other Shade Trees
  • Flowering Trees
    • Column 1
      • Crape Myrtle Trees
      • Dogwood Trees
      • Flowering Cherry Trees
      • Flowering Pear Trees
    • Column 2
      • Flowering Plum Trees
      • Magnolia Trees
      • Redbud Trees
      • Other Flowering Trees
  • Fruit Trees
  • Shrubs And Hedges
    • Column 1
      • Barberry
      • Boxwood
      • Butterfly Bush
      • Cherry Laurels
      • Encore Azaleas
      • Gardenias
    • Column 2
      • Hydrangeas
      • Knockout Roses
      • Lilacs
      • Rhododendrons
      • Wisteria
      • Other Shrubs & Hedges
  • Houseplants
    • Palm Trees
    • Tropicals
Menu Shopping Cart

What Is Urea?

Home Informative What Is Urea?
What Is Urea?
Sep 23, 2015 | Posted by Dave G | Informative | 4 comments |

Urea is a form of nitrogen that is made in the kidneys to excrete excess nitrogen, mostly from eating protein, which cannot be stored in the body. It is also manufactured on a large scale for use as a fertilizer, although there are some other uses in explosive making, medicine and even cleaning car exhaust gases.

Almost all the urea manufactured is converted into urea-formaldehyde, which is the most common type of nitrogen fertilizer used in agriculture and gardening.

Urea is very soluble in water, so if applied as a fertilizer by itself only a very small amount can be used and it will quickly be carried away in drainage. The urea cannot be used directly by plants but it is naturally converted into ammonia on contact with water in the soil. This then dissolves in the water and can be absorbed by plants for growth. Nitrogen is needed by plants to make protein and also to make chlorophyll, the green pigment in plants used to trap light and make sugars to grow.

However, if there is too much urea or ammonium in the soil it will draw water out of the roots and cause ‘fertilizer burn’, with the leaves shriveling and dying, often also killing the plant. This means that pure urea must be applied in very small amounts very often to be effective as a fertilizer. This is also what happens when dogs or cats urinate on your lawn.

Methods For Slowly Releasing Urea

So scientists worked on ways to save the cost and labor of these frequent small applications. They developed two methods of slowing the release of urea.

Water-Resistant Coating

The first method adds a water-resistant coating to a granule of urea and is called controlled-release. Examples are Nutricote™ and Osmocote™. These forms have a resin or polymer coating to slow down the release. Release of nitrogen is mostly influenced by temperature and higher temperatures accelerate the release. This is usually a good thing, since during warm weather when plants are growing more will be released, but in cooler weather less will be released, matching the growth of the plants and preventing pollution of drainage water. These granules are often found in fertilizers that last a whole season and are great for pots and planters. Other plant nutrients are added to make a complete fertilizer.

A less-expensive type of coating is SCU (sulfur-coated urea). Here the urea granules are coated with molten sulphur, wax and then clay. The activity of soil microbes and water penetration through cracks in the coating allow the urea to escape into the soil. This material is cheaper to manufacture, so it is widely used in lawn fertilizers. Be careful handling lawn fertilizer, because if the granules are crushed they will release all the urea at once and cause burn which could kill the lawn.

Urea-Formaldehyde

For cheaper fertilizers, especially for agriculture, the urea is turned into a less-soluble form called urea-formaldehyde. This does not contain the formaldehyde used to preserve dead animals. Since this does not immediately dissolve in water, it will stay in the soil as a solid until it is broken down. The molecules of urea-formaldehyde are of different sizes, depending on how exactly they are manufactured, and they have different degrees of solubility in water, affected by temperature.

As well, soil microbes are needed to break down this material so plants can absorb it. Microbes are also more active at higher temperatures, so overall the rate of release of the fertilizer depends on the temperature, since both solubility and the amount of microbe activity is influenced by the soil temperature. Release is very slow below 50 degrees, so this material can be applied to lawns and gardens in the late fall. No nitrogen will be released until the soil warms up in the following spring, and a spring fertilizer application is not needed– a job saved at a busy time of year.

Should I Use Urea On My Plants or Lawn?

So you probably did not know that when you use a fertilizer on your trees, your lawn, your vegetables or your flowers, you are probably using urea in one form or another. Because it is also present in urine, there are those who suggest peeing on your compost heap is a good idea. The choice is yours!

These kinds of fertilizers are essential for large-scale agriculture to feed a constantly growing world population. Chemically speaking what the plant takes up through its roots is identical, no matter where it came from. Organic material is essential for preserving the quality of the soil, but it is an often inefficient way to give plants nitrogen. If chemical fertilizers are used wisely they can be a great benefit to humanity.

4 Comments
3
Share

4 Comments

Leave your reply.
  • Geoff
    · Reply

    December 26, 2017 at 6:37 AM

    Hi there
    We have a mature mulberry tree that is fruiting at present
    After many years the local bats have finally discovered the free meal and are … expressing …. their gratitude – all over the neighbours paving

    Is there a way of deliberately over-using nitrogen fertiliser to stop it fruiting but in a way that is safe for the tree ?

    Cheers
    Geoff

    • David Goodfellow
      · Reply

      Author
      December 26, 2017 at 7:38 AM

      Hi Geoff,
      Mulberry trees planted near paving sure can be a mess, and with the bat poop too, that sounds nasty! Sadly, I don’t think over-feeding a tree that is already a vigorous grower is going to work – probably just turn it into an even bigger fruit/poop producer. A better approach might be to prune very hard each year, so that you get only young, one-year old shoots, and so no fruit. However on a ‘mature’ tree that doesn’t sound like a realistic option. Maybe remove it completely and plant a beautiful flowering tree that won’t make a big fruit mess!

  • Aaron
    · Reply

    October 29, 2018 at 8:32 AM

    Hi Geoff,

    This is an interesting read.

    I’ve planted approx 30 magnolia Little gems at are approx 1.2m tall now. I’ve been removing the flowers to try to encourage the plants to take off with a heap of new growth.

    What are your thoughts on potentially using ag. Urea to encourage growth? I’m trying to create privacy from neighbours. I obviously don’t want to harm to trees either. If not urea, what can I use?

    • G Dave
      · Reply

      Author
      October 29, 2018 at 9:41 AM

      I don’t think anyone, farmers included, are using straight urea – the agricultural urea is probably urea-formaldehyde. I would not suggest using a straight nitrogen source on your trees – it will probably cause unbalanced growth, with week stems, and be more pest and disease prone. Better would be to use a blended fertilizer for evergreen trees. These have a lot of nitrogen, but with phosphates and potassium too, plus iron and other micronutrients, for balanced growth. If you choose something more expensive you should be able to get a granular form with Osmocote or SCU in it, so you only need to feed once – in early spring.

      Removing the flowers will only have a limited value – enjoy them and remove them after flowering. That way you prevent seed formation, which does divert a significant amount of energy away from growing leaves and stems. Seems a shame to remove the flowers, when youthful flowering is one of the reasons to grow this variety. . .

      Remember that ‘Little Gem’ is a small form in part because it simply doesn’t grow at the same rate as the wild plant. A season’s growth is probably about half the length of that seen on full-sized trees. The advantage is that it will naturally grow dense, and won’t become too big in your lifetime to need elaborate trimming. It is not like smaller forms of trees grow at the same rate as big ones, and then miraculously stop growing when they reach a smaller height. It doesn’t work that way.

Leave a Reply to Geoff

Your email is safe with us.
Cancel Reply

Categories

  • Diseases And Pests
  • Evergreen Trees
  • Flowering Trees
  • Fruit Trees
  • Guides
  • Informative
  • News
  • Ornamental Trees
  • Plant Guides
  • Privacy Trees
  • Shade Trees
  • Shrubs And Hedges
  • Tree Care
  • Uncategorized

Recent Comments

  • Dave G on Cold Hardy Holly Bushes
  • Mary Kritz on Cold Hardy Holly Bushes
  • Dave G on The Story of Lilacs
  • judykirk100 on The Story of Lilacs
  • Dave G on Trees and Shrubs for Florida

Recent Posts

  • Rebloom or Encore Azaleas – Which Should I Grow?
  • Th Taming of the Mountain Laurel
  • Eastern Arborvitae – the Tree for Cold Seasons
  • The Story of Lilacs
  • Japanese Maples – Bark Can be Beautiful Too
Register for an account and get discounts, gardening tips, six-pack abs and more! Sign Up Today!


We ship amazingly beautiful and healthy trees directly to your door! Let's cultivate this earth together!

Contact Info

  • The Tree Center
  • (888) 329-0140
  • www.thetreecenter.com
  • Contact Us
  • The Tree Center Reviews
  • The Tree Center Etsy Reviews
  • The Tree Center Houzz Reviews

About Us

  • About The Tree Center
  • Order Status
  • FAQ's
  • How We Ship
  • Returns
  • Warranty
  • Reviews

Educational Info

  • Blog
  • Arrive Alive Guarantee
  • Hardiness Zone Map
  • Trees For Your State
  • Planting Guide
  • Fast Growing Trees

© 2019 · The Tree Center

Prev Next