Archive for fertilizer

COMPOSTING YOUR WAY TO A BETTER GARDEN

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COMPOSTING YOUR WAY TO A BETTER GARDEN

By:  Emily Shirley, Advanced Master Gardener

Soil is the most precious resource in your garden.  Some have well-tended soil (from previous owners), while others, particularly those moving into new homes, inherit a rubble-filled mass.  However, any soil can be improved through time and effort.  For example, when the Master Gardeners began gardening in the Demonstration Garden a few years back, we were given use of the property that was formerly an old rodeo arena.  It was very compacted, and after just a few inches we hit red clay that had been hauled in for years and driven over with tractors.  By the time we finished amending the soil we were growing beautiful plants – vegetables and ornamentals.

If you have been around the gardening world very long, you have heard the terms “black gold”.  What we are referring to is composted material that is very precious in terms of gardening use – or compost.  Composting is the natural process that turns raw organic ingredients into humus – that earthy, dark crumbly, fully decomposed end product.  If you regard your soil as a living entity, you will see that essential plant nutrients are cycled by a microscopic army of inhabitants and larger worms, insects and grubs.  All these creatures need air, moisture and food.  Using manure, garden compost and other sources of organic matter is the key to sustaining this soil life and keeping the soil healthy.

It is always good to start by working with what you have – compost what your yard produces first, and import materials only when they are convenient and of special value to your composting.  Compostable materials from your kitchen, such as fruit and vegetable scraps, plus garden materials can easily be reused to cycle their nutrient value, carbon and nitrogen back into the soil to grow more food or plants.

To avoid waste from what you do not use in the kitchen, don’t throw it in the garbage, compost it!  Once you start saving your food scraps from the kitchen two things will happen.  You will simply be amazed at how much you have been throwing in the garbage that could have been used for composting.  And, you will never go back to throwing these things in the garbage again because you will soon realize how valuable these materials are for your gardening.  Most landscapes produce plenty of fallen leaves, grass clippings, and withered plants to toss in there.

This is a very simple process.  You need something for collecting your kitchen food waste to get started.  You can spend a lot of money for products that are sold for this purpose, or you can make it simple by having a simple five-gallon bucket with a lid, just outside your kitchen.  As you prepare food or clean out the refrigerator, just toss things into a small container and each evening empty that container into your larger bucket just outside the kitchen door.  Once you have enough in the outside container to throw out, you take the contents from your food scrap container to a compost pile.  You can even get creative and even make it even easier by having some trenches dug outdoors in an area you plan on gardening in at a later date and bury your food scraps in those.  Now, just let things sit in your compost pile a while and decompose and when it is ready, start using it.

So how do you know when your compost is ready to use for planting projects?

To evaluate your compost to determine if it is ready you can get very complicated, (that science thing again) or you can just use what you have – your eyes, nose and hands – to determine if it’s ready.  Visual inspection will reveal even color and consistency with a sprinkling of still-identifiable, undecomposed items, such as a peach pit or chunks of corn cob.  Your nose will detect an inoffensive, earthy smell with no sharp or sour odors.  To the touch, your finished compost will feel cool (no apparent heating), moist, and crumbly.  Once your compost meets these standards, let a few lettuce (or other) seeds pass final judgement.  Combine compost with an equal amount of potting soil and plant seeds in the mixture.  Sow the same kind of seeds in plain potting soil at the same time, and compare the progress of each planting.  If the seeds grow equally well in both, your compost is ready to roll; slower growth in the compost mixture means your compost needs more time to mature before you use it in planting projects.

Hints:

  •  Composting is not fast – you have to be patient and give it time. Slow compost is good compost.
  • Place a thick layer of newspaper (not the slick colored sheets) at the base of a curing compost pile to deter invasive tree roots.
  • Inadequate moisture is one of the most common reasons for compost to fail to make good progress.  Compost microorganisms need moisture.  You have to give your pile some moisture during these Louisiana hot days.  It is important to moisten ingredients as you add them to your pile, and to replenish moisture as you turn or aerate compost.
  • In an open heap, you don’t have to aerate, because the heap has plenty of exposed surface area, and will make its own air pockets as the materials shrink and turn into compost.  (Note:  I have a very large compost pile and I just use the tractor front-end loader to move it around occasionally.)
  • After a year or two of using compost In the garden every chance you get, you will discover a new pleasure in gardening.  You will notice that you can pull weeds more easily.
  • It is a good idea to only use your composting pail for just composting.  Don’t contaminate it with other things, for example, using your bucket to pick up behind the dog in the yard.

So how do you then actually use this compost once it is decomposed and ready?

  •  Treat every plant you grow to some form of compost.
  • Blanket beds as you renovate them between plantings.
  • Amend planting holes, or mix your best batches into homemade potting soil.
  • Use rough-textured, partially decomposed compost as mulch.
  • You can use it as a soil conditioner for all type of plants.
  • You can use your compose to mix with potting mix that you already have.
  • You can use it as a slow release fertilizer, gradually feeding plants over a long period of time.
  • You can use it for mulch for pots and gardens to protect plant roots from the sun and wind and to prevent erosion and reduce soil diseases.
  • (composting – continued)
  • You can use compost as a top dressing for lawns, to add nutrients and fill in gaps to encourage healthier grass roots and thatch.
  • Use it as an amendment to prove sandy and clay soil structure by binding soil particles together – helping aerate, retain moisture and nutrients.
  • Make a liquid “compost tea” fertilizer.
  • Compost mixed into the soil between plantings is the best way to keep the soil from becoming exhausted.
  • When you are ready to plant, mix in the compost along with organic fertilizer sufficient to meet the needs of the crop, and you are good to go.

 

 

 

 

 

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George’s Soil Recipe

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George’s Soil Recipe:

by George Giltner, Advanced Louisiana Master Gardener

Ingredients:

  • Compost (homemade or purchased)
  • Garden soil (Not “potting soil”) Note: Your own top soil or soil from the garden is recommended.
  • Expanded Shale
  • Zeolite

WHEN USING THIS SOIL MIXTURE FOR CONTAINER PLANTING:

If you have several containers you will want to mix up a batch of soil mixture and then fill your containers.  In the bottom of your container(s), add about 2 inches of volcanic rock.  This is called “Red Lava Rock” at most stores or garden centers.  This rock allows for drainage and keeps the soil from coming out of the bottom of the pot, and it allows for oxygen.

The next thing you are going to do is mix up a batch of the soil mixture:

Use a wheelbarrow or other type large container and combine the following:

  1.  Compost — Use a five-gallon bucket and put in 1 ½ buckets of compost in your mixing container. You can use your own compost or purchase some. (And you know we are going to tell you that your own homemade compost is best.)Garden Soil (Any will do, but your own is best.) (Use Five-Gallon Bucket and put in 1 ½ buckets).

 

  1. Garden Soil (Any will do, but your own is best.) (Use Five-Gallon Bucket and put in 1 ½ buckets).
  2. Expanded Shale (Use Five-Gallon Bucket and put in 1 ½ buckets).
  3. Zeolite (This is called “Horse Stall Refresher at Tractor Supply) (Use approximately 1 cup – it doesn’t take much of this.)

(Note:  If you just want to use the mixture in one planter and not mix up a batch, you could just put in red lave rock, use a container such as a five-gallon bucket and add 1/3 expanded shale, 1/3 compost and 1/3 potting soil to fill the five-gallon bucket.  Toss in a small handful of zeolite and mix this up.  Use the mixture to fill your planting container.)

When you are ready to plant, fill your planting container(s) almost to the top with your mixture, allowing room to plant and to water.  Add your plants and water in.  The organics in the pot will have to be replenished as they break down over time.
WHEN USING EXPANDED SHALE SOIL MIXTURE FOR IN-GROUND GARDENING:

Obviously you will not be able to mix up large enough batch for in-ground planting.  In this case you will just add a couple of inches of fresh compost, spread about two inches of expanded shale on the top, then sprinkle a light coat of Zeolite on top, then rototill in.

Explanation of why this Works:

  1. Compost is your nutrient source for plant fertility.
  2. Garden soil provides life (microbes to insects), nutrients, humus, minerals, etc. much like the compost.
  3. Expanded shale provides a large porous structure for air and water exchange, and it contains charge sites for nutrient retention (improves CEC).  Roots need oxygen and a stable supply of water that expanded shale provides this.
  4. Zeolite is a group of minerals consisting of hydrated aluminosilicates of sodium, potassium, calcium, and barium. They can be readily dehydrated and rehydrated, and are used as cation exchangers and molecular sieves.  Zeolite acts as a good binder for dry soil (for example soil that has too much organic matter and as a result it dries out).  Zeolite will bind the soil and keeps it from drying out.  Zeolite is much like expanded shale on steroids in a micro-sized granular form.  It encourages bacterial life in rhizosphere of the root zone.  Therefore your containers will have to be watered less, plants will grow healthier, and less nutrient amendments will be needed.  Once the expanded shale and zeolite has been added, it does not break down like many other soil conditioners.  These two soil conditioners have proven themselves in NASA Space Station experiments, and in down-to-earth gardens like the Dallas Arboretum.

 

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PRESIDENT’S MESSAGE

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By: Emily Shirley, President, Beauregard Master Gardeners Assoc.

Happy June!  If you live in the South, you know what we do in June and it does not necessarily have anything to do with gardening.  We prepare for hurricane season.  This month’s newsletter will toss in a little reminder of things to do for this season.  As with all our newsletters, we publish with the new gardener in mind, while also reminding seasoned gardeners of things they already know. 

 

This month we give you articles on composting and even share that now not-so-secret “Master Gardener soil recipe” developed by Advanced Master Gardener, George Giltner.  And you say, what else is there to learn about composting?  It really is science and I am one of those people that have to let science soak in.  Composting really is such an important topic not only for the home gardener, but for everyone involved in tending the earth and growing crops, whether you live on thousands of acres or on a tiny plot. If you are going to garden, “it all starts with the soil.” 

Soil must be replenished. And adding compost, (organic matter), is how soil is replenished. There is no substitute for adding back organic matter to your soil.  If you are gardening and you aren’t composting, make it a resolution to start a compost pile, or two or three, somewhere in your garden area. You’ll be a better gardener and have better soil too.

 

The AgCenter has been getting calls about these “tiny worms” that are coming inside the home so we are also sharing information on these “Millipedes”.  And, oh the confusion between the leaf-footed bug and the milkweed assassin –we will try to clear that up for you too. Probably the last thing a gardener would want to do is kill off a beneficial insect, like the Milkweed Assassin Bug, that is controlling pests (flies, mosquitoes, caterpillars, cucumber beetles, the Asian citrus psyllid, aphids, army worms, and other prey 6x their size). 

 

We know that next to tomatoes and peppers, the next vegetable that most gardeners always grow is squash.  But growing squash means there are many questions to ask about what is going on when you do have issues.  The article “Six Reasons Squash Fails and What to Do About It” will hopefully help you with all your squash issues. 

Emily

 

 

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Is your Garden Soil Safe for Vegetable Gardening?

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Is your Garden Soil Safe for Vegetable Gardening?

By George Giltner, Adv. MG, Biology MS

Most of our gardens are safe and natural ecosystems, which grow wholesome, nutrient dense foods.  We work and handle the soil, enjoy the rich earth aroma, and appreciate the vital processes of living organisms that recycle nutrients, filter water, and produce our crops.

However, soils can be polluted just like water and air.  Lead, arsenic, and cadmium  are toxic heavy metals that are of concern.  Once these heavy metals are introduced into soil, they persist a very long time.  Knowing the history of the garden location can help to identify areas that are contaminated.  Examples of contamination from the past include arsenic treated lumber residues, some fertilizers, old orchard sites where lead arsenate pesticides were used, a gun range, lead bearing paint residues, and  even soil near roads in the time of leaded gasoline.

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Here are watermelons at the Master Gardener Demonstration Garden where George has various project. Photo by Jimmy Earl Cooley, MG’er.

Most common fertilizers are not a significant source of heavy metals.  Nitrogen and potassium fertilizers are generally free of toxic metal content, but phosphate fertilizers often contain cadmium depending on the mining site.  Excess phosphorus typically is “tied-up” with insoluble compounds like calcium phosphate, therefore it lingers in the soil for years.  Use soil tests to determine if additional phosphate amendments are needed.  Thus, avoiding unnecessary phosphorus fertilizer applications may prevent the undesirable cadmium additions, too.

Micronutrient fertilizers have been and are still being produced from recycled toxic materials.  “Ironite” has contained as much as 3600 ppm arsenic and 2900 ppm lead.  No federal standards for heavy metals in fertilizers exist.  Composition of fertilizers is in the control of the states.  However, Washington State does require testing for 9 heavy metals with results on the web.  Gardeners from other states use their postings to look up heavy metal concentrations in commercial fertilizers.

What are the negative effects of heavy metals on human health?  Children bear the greatest risk as the developing brain and IQ are especially vulnerable to lead.  Even the lowest detectable quantities are considered toxic to children.  Children’s behavior as “Rug Rats” with mouthing and crawling on floors, exposes them to greater quantities of dirt and dust. Chromosome damage, nerve damage, cancer, etc. are among other toxic effects of heavy metals on all of us.

Vegetables are not all equal in their ability to uptake heavy metals.  Some are concentrators and others are not.  Leafy greens like lettuce, and root crops like carrots will have more than fruits like tomatoes.  Some plants like water hyacinths are super concentrators that may have thousands of ppm of mercury from water sources.  Therefore it should not be used as compost material for soil.

How do you get your soil tested?  The LSU AgCenter Soil Lab can do an optional lab test for heavy metals for an additional $5.  Another reliable lab is TP&S Lab (956-383-0739) which will cost around $100.  Interpretation of results can be done with on-line research.  Common sense guidelines – “Less is better”.

Please note the first paragraph of this article, “Most gardens are safe-“.  This article is for awareness of heavy metals.  It is not meant to scare or deter in any manner from the joys of gardening.

 

 

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Soil Science from the International Space Station Comes Down to Earth – In your Garden!

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Soil Science from the International Space Station Comes Down to Earth – In your Garden!

By George Giltner, Adv. Master Gardener, MS Biology

NASA has been developing artificial soils for several decades for use on long duration space flights.  These trials have proved that numerous crop species have growth and development similar to plants grown in ground controls.

2014 zeolite images

The advantages of the “Zeoponic Soil Systems” is that only water is needed for activation, and yields are substantially higher than those obtained from the field.  The objective is to have a soil substrate for plant growth that can be used in a regenerative life-support system ( a sealed sustainable living space).  Data from the Lada greenhouse in the space station has helped advance Earth-based greenhouses and controlled environment Ag systems.  This information is also used by researchers and farmers to produce better, healthier crops in small spaces with optimum amounts of water and nutrients.

Commercial products have been on the market for some time.  Examples are “Zeo-Pro” which is used as a slow release fertilizer on golf courses.  Another product “Miracle Mountain Zeolite” sells zeolite as a garden amendment.  For gardening purposes, be sure the zeolite is without a sodium load, examine the heavy metal report, and assure the product is oriented for Ag purposes. Many other products and expanded use of zeolites are expected as advantages are learned.  It is definitely a 21st century product.  Applications include odor control products (Horse Stall Refresher), Fish hatchery water treatment, a Portland Cement substitute, Kitty Litter, and higher yields in crops and pastures.

What are the benefits of using zeolite in horticulture applications?  1) The CEC (cation exchange capacity – value of available nutrients) is increased.  2) Soil porosity and water holding properties are improved which results in decreases in water run-off and ponding 3) Zeolite increases nitrogen retention by reducing ammonia volatilization, therefore reducing nitrogen pollution. 4) It improves the fertilizer efficiency by capturing nitrogen, phosphorus, potassium, calcium, magnesium and other trace nutrients for utilization by plants. 5) Zeolite can be used as an inorganic substitute for peat moss in mixes.  6) It helps to open compacted soils.  7) biological activity is increased by supporting nitrifying soil bacteria.

A most important use of zeolite is its role in developing controllable and renewable fertilization plans to provide plant growth nutrients.  It can be used to mitigate the adverse effects water contamination due to highly soluble and concentrated fertilizers.

Zeolite is a crystalline, porous alumino-silicate with a unique interconnecting, honeycomb lattice structure.  This structure of channels of negatively charged alumina, with neutral silica tetrahedral building blocks, can effectively capture positively charged nutrient ions.  Because of zeolite’s molecular composition, it has incredible absorbent and adsorbent properties.

In nature, zeolites are naturally formed microporous, alumino-silicates that are found where volcanic rocks and ash layers react with alkaline groundwater.  The mineral is also known as clinoptilolite.  Check bags of “Kitty Litter” and “Horse Stall Refresher” for clinoptilolite as the effective ingredient. Obnoxious odors and gasses are trapped in the mineral honeycomb structure of these commercial products like fertilizer nutrients are captured in soil-use zeolites.

Most of our local acidic soils are classified as Ultisols composed of kaolinite which has a very low ability (low CEC number) to retain plant nutrients.  Therefore most of the commercial fertilizer is lost through leaching with rains and irrigation water.  Typically the top 3 to 6” of topsoil contains nearly all of the nutrient value.  Additional nutrient depletion occurs when crops are harvested, and when the soil is left barren, and oxidized by tillage.  However this soil can be frequently amended with organic matter and humus to increase the pH to a more neutral value, and to increase the CEC to a higher fertility value.  This usually requires much labor and effort.

A better system may be to utilize zeolites, organic matter, and inorganic minerals.  This approach uses the advantages of each.  The zeolite adds a long term substrate to improve the CEC, porosity, nutrient and water retention, and microbial life.  The organic matter with cellulose gives life to the soil, water retention, porosity, structure and acts as a slow release fertilizer upon decomposition.  Inorganic minerals can be added to supplement deficiencies as indicated by testing or visual symptoms.  The overall effect is that leachate pollution is minimized, and fertilization, water, and labor cost are also reduced, while yields are high.

Researchers from the University of Cambridge (Aug 2013, Peter Leggo) has shown that even marginal land like deserts can grow fruits and vegetables using a zeolite mix with chicken manure.  Control experiments have shown that dew water can be held on zeolite until the hottest part of the day, which increases overall soil moisture content for plant growth. Dr. Peter Leggo of the Department of Earth Sciences says, “Previously, you’d douse crops with chemicals, and it caused a huge reduction in soil microbial diversity.  The material we’ve developed takes less energy to produce, improves soil structure, and enables you to grow crops on almost any type of soil”.  Plans are to commercialize the product for world markets.

You may wish to experiment in your own gardens with zeolite soil conditioners and fertilizers.  Let us know about your experiences and procedures to share with others in the 21st century.

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A New Additive for Poor Soils

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A New Additive for Poor Soils

By George Giltner, Adv. Master Gardener, M.S. Biology

Simply put, what does it take to have a good garden?  University of Cambridge researchers have developed an additive that is capable of growing crops on landfills, deserts, 3rd world agricultural wastelands, and even on gravel.  The ingredients are fairly common, therefore anyone should be able to use this additive or the garden principles of the components, to apply to practically any soil.  What are these mysterious substances – an organic composted manure and zeolite.   The zeolite is a ground, mineral-containing volcanic aluminosilicate rock.  Add the correct amount of good water, proper light, an appropriate temperature range, and air for a “successful garden”.  It is that simple.  Now let’s look at compost and zeolite to understand how they work for plants.

2014 zeolite images

Zeolite is formed from volcanoes when pressurized liquid aluminosilicates and other minerals are suddenly released into our atmosphere.  The liquid fizzes out gases, cools, then solidifies like a sponge with a high porosity (up to 45%) and a huge surface area (up to 450 meters/gram).  This open framework traps and exchanges valuable plant nutrients (positive ions like calcium, magnesium, ammonium, potassium and trace elements that are essential for plant growth and development).  This is what makes it ideal as a soil, compost, and fertilizer additive that captures, and slowly releases critical plant nutrients.  Zeolite also physically functions to improve soil structure which allows water and air to flow through with less nutrient leeching and long term soil improvements.  The cation exchange capacity (CEC) improvements jump from an approximate 10 (our poor Ultisol soil) to an excellent +120 meq./100g.

Organic plant and animal compost also improves soil structure, but the mechanisms are different from mineral Zeolite.  The “Super Glue” of the soil structure, glomalin (a glycoprotein), was discovered by Sara F. Wright, a USDA scientist in 1996 from fungi.  Glomalin along with humic acid, are a significant component of compost and soil organic matter.  These two complex organic substances bind, store, and slowly release mineral particles which results in improvements in soil quality.  Glomalin stores up to 27% of total soil carbon compared to humus’s 8%.  Also glomalin makes nitrogen available to soil, provides structure to hold water and for aeration, keeps spaces for root growth, and stabilizes the soil against erosion.  In crop soils where fungicides have been applied, there is a reduction in productivity, due to reduction of glomalin production.

The soil life factor of compost really gets the plants growing.  The action of microbes is phenomenal as atmospheric nitrogen is changed to useable forms of nitrogen by fungi, bacteria, protozoa and actinomycetes.  When these microbes excrete or die, useable minerals and organic compounds are released back into the soil as slow released nutrients.  Many new organic fertilizers list the beneficial microbes that inhabit the rhizosphere of roots to form symbiotic relationships (mycorrhizal, antibiotic, enzymatic, etc.)  with plants.  Larger forms of life, from insects to worms, open tunnels for root growth, gases, and water.

The balance and correct ratio of four chemical elements (calcium, magnesium, potassium, and sodium) influence the physical structure of the soil and the pH also.  A correct soil chemistry is necessary to build the house for the biology.  For example, if you have a soil or compost that is loaded with sodium from a tap water supply, your plants will not grow to their potential.  Excess sodium will cause soil structure to collapse, suck the life out of plants, and will destroy microbial life.  Calcium in cell membranes is the doorman that regulates the nutrients that enter the plant.  If you have too little calcium in plants, larger amounts of all other nutrients are required for the same yield.  And the complexity continues with other minerals.  Therefore your best plan is to get a soil test.  Get a box from the LSU AgCenter for quick results in several days.  Apply minerals as recommended in the reports.

Chances are that most compost additions will buffer the soil, will provide adequate nutrient levels, and will supply trace minerals.  Remember that there are accumulator plants that concentrate particular minerals and will affect the pH.  What you put into a compost pile is what you get out.  Therefore it is a good idea to test compost made from few plant sources before it is added to soil.  A wide variety of material usually produces the best mineral-balanced compost.

The most important aspects of gardening are knowledge and experience.   Like any art or science, it requires an input of effort, trial and error, and patience.  Additions of zeolite and animal compost to your soil will probably produce a decent garden.  However, learning the details of gardening will lead to spectacular gardens.  Master Gardener classes will begin in January.  Call the LSU AgCenter at (337)460-7006 for registration.

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Soil Fertility Factors

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Soil Fertility Factors

By George Giltner, Advanced Master Gardener

You don’t have to battle through botany, chemistry, cellular biology and physics to understand that when essential nutrients are not available to plants, they will not grow.  Common garden logic is in the “Law of Return”.  When plants are removed from a garden, along with them goes a portion of the nutrients in the soil.  Therefore the gardener must return that complement of nutrients in the form of fertilizer back into the soil to maintain its fertility.  Other nutrient-loss factors like water leaching, volatile gases lost in decay, pest grazing, mineral insolubility, even removing weeds, and others contribute to fertility losses.

Soil testing can identify these losses.  Also soil test results supply information on soil mineral corrections.  Soil test sample boxes are available in a convenient mail-in form that can be obtained from the AgCenter.  Results are usually emailed or mailed within a week.

Organic matter additions are an excellent means returning nutrients and minerals back to the soil.  Consider making compost year round for garden amendments.  The compost is important to the soil structure, the microbes to insects in the soil-food web, moisture and mineral retention, and to the environment.  Mineral fertilizers do return mineral nutrients quickly to the soil, but it is in a leachable form that is destructive to soil life and the long term detriment of soil fertility.  Organic fertilizers provide a wide range of macro and micro nutrients that chemical fertilizers do not have.

Plant nutrient intake is influenced by temperature, mainly from 42 to 95 deg F for most plants, due to limits on photosynthesis and microbial produced nitrogen.   Also mycorrhizal fungi are very important for most of plant’s phosphorus uptake.  During early spring, one may notice purple leaves on tomatoes exposed to cool temperature soils.  This is probably due to lack of phosphorus transport activity of the fungi due to cool temperatures.  In summer, exposed soil around plants can reach temperatures around 120 deg F, thus limiting photosynthesis.  Mulching can reduce these temperatures by a significant 30 degrees, thus allowing for moderate temperatures for photosynthesis.

Problems with pH are typical with chemical gardeners.  Additions of ammonium are converted to nitrates by nitrogen-fixing soil bacteria, resulting in a lowering of the soil pH.  As the soil pH goes more acid, less and less of soil minerals are available to plants.  If lime is added during the plant growth cycle, “lime shock” occurs which leads to further problems with nitrogen loss, and a lock up of phosphorus in insoluble (unavailable) calcium phosphate.  Plant microbes are affected and other minerals become unavailable for plant absorption.  With a healthy organic soil, plants synthesize and release exudates that adjust the pH through action of the microbiological community.  Therefore organic soils are much less pH complicated to the gardener.

Poor soil aeration can devastate beneficial microbes in soils.  A compacted soil results in trapped carbon dioxide reacting with water to form carbonic acid. Excess carbonic acid then reacts with organic matter to form deadly alcohols and other noxious chemicals that kill root cells.  Aerobes in the soil are replaced with anaerobic life which ties up nutrients that would be going to plants.  Organic soil will hold its loose structure even after rains, whereas mineral soils will collapse and become compacted. A fluffy soil that can allow oxygen and water to flow easily is ideal. Water and oxygen movement is necessary to maintain the microbes and to transport soluble nutrients to plant root systems.

Chemical balances influence availability of individual mineral nutrients.  There is completion among ions of minerals for absorption on root sites.  Example: If you have too much potassium, magnesium, or sodium in your soil, plants will take up less calcium.  As a result, blossom-end rot would be much more common in your tomatoes, squash, and other plants.  This is why frequent soil tests are very important to chemical gardeners, but less so to organic gardeners.

Many people want to become gardeners, especially with rising food prices, problems with food safety, and reports of lack of nutrients in food items.  Too many are taking the “modern path” by pouring on N-P-K fertilizer without knowing how the fertilizers work.  These people use three times the nitrogen that farmers use.  This results in excess nutrients (esp. nitrogen and phosphorus) that are washed into waterways and harm aquatic environments, plus their garden is a flop.  To become a responsible and knowledgeable gardener, take the Master Gardener Classes at the LSU AgCenter. For more information about Master Gardeners, call the AgCenter at 337-463-7706 or email khawkins@agcenter.lsu.edu.

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