Digging It: Get Your Soil Ready

When it comes to soil you can use both nature and science to get the perfect soil conditions.

In Australia we have some of the best soils in the world so the nature part is covered.

So, that leaves the science part, let’s put on the white coat and reflective plastic glasses, geek the hell up and get our science ON.

We all know that humans, animals and plants need nutrients to survive and nutrients can be ‘macro-nutrients’ (required in small quantities) such as nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sulphur (S) and magnesium (Mg) or ‘micronutrients’ such as zinc (Zn), copper (Cu), iron (Fe), boron (B), and molybdenum (Mo) (required in larger quantities).

As many soils do not provide all the nutrients in quantities needed by crops with continuous cropping the soil will require replacement of nutrient called fertilizers.

Fertilizers are any solid, liquid or gaseous substances containing one or more plant nutrients in known amounts applied to the soil, directly on the plant (foliage) or added to aqueous solutions (as in fertigation) to maintain soil fertility, improve crop development, yield and/or crop quality.

The purpose of fertilizer use, especially for higher yields, is identical in temperate and tropical climates:

  • to supplement the natural soil nutrient supply and build up soil fertility in order to satisfy the demand of crops with a high yield potential;
  • to compensate for the nutrients exported by the harvested products or lost by unavoidable leakages to the environment in order to maintain good soil conditions for cropping;
  • 
to supplement the natural soil nutrient supply and build up soil fertility in order to satisfy the demand of crops with a high yield potential 
to compensate for the nutrients exported by the harvested products or lost by unavoidable leakages to the environment in order to maintain good soil conditions for cropping. Fertilizers are classified into two major forms:
  • can be organic;
  • can be mineral/manufactured.

Manufactured fertilizers are classified according to different criteria as follows:

Number of nutrients

  1. single-nutrient or straight fertilizers (whether for macro or micronutrients):  examples:  urea (46-0-0), triple superphosphate (0-46-0),muriatic of potash (0-0-60), zinc/iron chelates, boric acid, etc;
  2. multi-nutrient/compound (multiple nutrients) fertilizers, with 2, 3 or more nutrients:  _examples: compound fertilizers (15-15-15), diammonium phosphate (18-46-0), monopotassium phosphate (0-47-31), etc.

Type of combination

  1. mixed fertilizers or ‘bulk-blends’ are physical mixtures of two or more single-nutrient or multi-nutrient fertilizers;
  2. Complex fertilizers are products in which two or more of the nutrients are chemically combined (e.g. nitrophosphates, ammonium phosphates).

Physical condition

  1. solid (crystalline, powdered, prilled or granular) of various size ranges;
  2. liquid (solutions and suspensions);
  3. gaseous (liquid under pressure, e.g. ammonia).

Nutrient release

  1. quick-acting (water-soluble and immediately available);
  2. slow-acting (transformation into soluble form required, e.g. direct application of phosphate rock);
  3. controlled-release by coating;
  4. stabilized by inhibitors.

The principles of the right use of nutrient source, rate, time and place form the minimum basis of any local nutrient stewardship system.  Best management practices must be applied to all of these areas to achieve local economic, social and environmental goals.

N = Nitrogen

Encourages plants to produce dark green leaves. This is the chief staple in the diet of most plants. Yellowing leaves means the plant isn’t getting enough nitrogen from sources in the soil.  But it only takes a little nitrogen to do the job, and if your goal is to set fruit or vegetables, you don’t want to use excesses of nitrogen because you will only get overgrown plants and little to no fruit.

Nitrogen can leach quickly from the soil requiring frequent reapplication. Nitrogen applied in the nitrate form is usually inorganic, fast acting, but can leach quickly into surface and groundwater. Nitrogen applied as ammonium is from organic sources (blood meal) and IBDU (isobutylidene diurea – a synthetic organic fertilizer) and is released more slowly and lasts longer in the soil.

P = Phosphorous

Stimulates root growth. All plants need it to get their root foundation off to a healthy and vigorous start so they can support all the growth on top, but root crops and bulbs especially need phosphorous to do well. Phosphorous and potassium don’t move readily through the soil and should be applied near plant roots to do the most good.

K = Potassium

Is critical to the continuing health of all plants, especially during the second half of the life cycle in fruit and vegetables when the plants are setting flowers and bearing fruit. Potassium is often expressed as potash or water-soluble potash. Potassium and phosphorous don’t move readily through the soil and should be applied near plant roots to do the most good.

Did you get all of that?   Nope?    No worries, here is a little chart (print it for the fridge) from the weekend gardener:

THE BEST GARDEN FERTILIZERS
Type N-P-K Ratio Uses / Plants
ORGANIC
Alfalfa Meal 2.7 – .5 – 2.8 Well balanced, rapidly available. A quick-acting source of nitrogen and some potash. Contains growth stimulants and invigorates the biological activity in the soil. Good for lawns, roses, and a general purpose organic fertilizer
Animal Manure (cow, dry) 2 – 1 – 2.4 Slow release.  Best when composted. Its slow release makes it most valuable as a soil conditioner, and good for all-purpose garden uses.
Animal Manure (horse) 2 – 1 – 2.5 Slow release when dry, rapid release when fresh. Should be composted first, fresh can burn plants if applied too generously. Good for all-purpose garden uses and as a soil conditioner.
Animal Manure (poultry, dry) 4 – 3 – 1 Very rapidly available nitrogen and phosphorous. Should be composted first, fresh manure will burn plants. Good for bulbs, root crops, flowering and fruiting plants and trees.
Balanced Fertilizers Available in various proportions such as a 10-10-10, or

5-5-5

Well balanced fertilizer giving plants all nutrients in equal proportions. Good for all-purpose garden uses on trees, shrubs, flower beds, fruit trees, lawns, perennials, container plants, etc.
Blood Meal 13 – 2 – 1 Rapidly available nitrogen. Stimulates microbes in the soil. Blood meal is completely soluble and can be mixed with water and used as a liquid fertilizer. Also works best when scattered on top of the soil and watered in. Good for compost piles to speed decomposition, repels deer and rabbits, and used for yellowing plants in need of nitrogen.
Bone Meal 3 – 12 – 2 Rapidly available phosphorous. Mildly increases soil pH. Best for fruit trees, bulbs, and flower beds.
Compost (dry, commercial) 1 – .8 – 1 Balanced, slow release. Great to use for a lawn fertilizer (Read How To Compost Your Lawn). Good used in vegetable gardens as long as at least several large handfuls are used per plant and worked into the soil to make sure enough nutrients get to the plant. Good choice for the busy gardener.
Compost (homemade) 1 -.5 – 1

up to

2 – 1 – 2

Balanced, slow release. Great to use for a lawn fertilizer (Read How To Compost Your Lawn). Good used in vegetable gardens as long as at least several large handfuls are used per plant and worked into the soil to make sure enough nutrients get to the plant. Good choice for the busy gardener.
Cottonseed Meal 6 – 2 – 2 Rapidly available nitrogen that is broken down slowly and is available to the plant over a period of time. Will acidify the soil so best used for crops that prefer low pH such as azaleas, blueberries, citrus, dogwoods, hollies, and strawberries. May contain pesticide residues.
Fish Emulsion 4 – 4 – 1 Rapidly available nitrogen. Apply as a foliar spray in early morning. When used as a liquid drench, results are quicker than with other organics. It is a low-nitrogen concentrated liquid food containing a wide range of trace elements that will green foliage, grow vigorous roots and big flowers while also enriching the soil.  Good all purpose fertilizer. Fish emulsion however is heat processed meaning that a lot of the nutrients and amino acids are totally destroyed during processing. The odor dissipates rapidly after application. If there is a choice, use hydrolized fish fertilizer instead of emulsified.
Fish – Hydrolized 2 – 4 – 2 Much better than fish emulsion because it is cold processed instead of heat processed and has no odor. Hyrdrolized, or cold processed fish, keeps all of its nutrients and proteins and allows them to be readily available to the plant. It also makes those nutrients water soluble, so you can use them for foliar spraying or drip irrigation, with no worries of clogging the drip line.   Good all purpose fertilizer especially good for flowers, vegetables, and herbs. (Read Hydrolized Fish Fertilizer).
Fish – Meal 10 – 4 – 4 Rapidly available nitrogen. Good to be used in early spring at transplanting and any time plants need a boost. Don’t scatter fish meal, because of its strong odor; plant it in a series of holes about ten inches (25 cm) deep that can then be covered with about four inches (10 cm) of soil. Good for yellowing, nitrogen deficient plants that need a quick boost.
Greensand 0 – 0 – 7 Very slowly available potassium. Can last up to 10 years. Loosens clay soils. Apply in the fall for benefits net season. Mostly used as a soil conditioner when amending.
Liquid Seaweed 4 – 2 – 3 Slow release of potassium and good source of micronutrients. Contains plant growth hormones that stimulate plant and root growth. Gives a quick boost for greening foliage, and when mixed with fish emulsion or hydrolized fish, it can’t be beat because the two benefit one another in so many ways. Its growth promoting substances enhance plant development, color and vigor. Seaweed has also been found to increase plant hardiness and resistance to adverse environmental conditions, such as early frost, extreme heat. and lack of moisture. (Read Kelp Can Save Your Fruit).   Used as a seed inoculant, seaweed fertilizer increases and accelerates germination, and enhances the rapid development of a healthy root system. Good for all plants as a general energizer.
Wood Ash 0 – 1 – 7 This is not a recommended fertilizer to use. It was only included here since many have questions about it. Nutrient amounts are highly variable. Good source of potassium and calcium, however it will rapidly increase soil pH. Can injure soil microorganisms. Never use without doing a soil test first to check your soil pH. Use sparingly in the spring and dig under. Don’t use near young stems or roots. (Read Wood Ash As A Fertilizer).
Worm Castings .5 – .5 – .3 Well balanced fertilizer used mostly to improve soil structure. The castings slowly release nutrients needed for healthy plant growth and increased production rates for fruits and vegetables. Good for herbs, fruits, or vegetables.
INORGANIC
Acidifying Soluble 30 – 10 – 10 Good source of nitrogen for plants that prefer acid soil conditions such as azaleas, blueberries, camellia, citrus, crape myrtle, ferns, holly, magnolia, rhododendrons.
Ammonium Nitrate 35 – 0 – 0

or

28 – 3 – 4

Rapidly available nitrogen. Used most often on lawns for fast greening and rapid growth. Good for yellowing, nitrogen deficient plants that need a quick boost. Leaches quickly from the soil.
Balanced Fertilizers Available in various proportions such as a 10-10-10, or

5-5-5

Well balanced fertilizer giving plants all nutrients in equal proportions. Good for all-purpose garden uses on trees, shrubs, flower beds, fruit trees, lawns, perennials, container plants, etc.
Liquid or Chelated Iron 15 – 4 – 6 Good for plants that are yellowing and iron deficient due to compacted or poorly drained soil. Cold weather, and alkaline soil also can make iron less soluble. Good for gardenias, boxwood, camellias, pin oak.
Superphosphate 0 – 20 – 0

or

10 – 50 – 10

Rapidly available phosphorous. Used to promote flowering and fruiting. Good for container grown plants, flowers, perennials, and root and bulb crops such as onions, tulips, and potatoes.

Just remember don’t buy until you research.    In our humble opinion there’s nothing worse than using the wrong fertilizer and seeing little or no growth.

Get your soil right and you’ll be on the way to big harvests and lovely gardens.

Love Gardenhood

PS.   One of our readers (Cec Pedersen) sent us the Mulders Chart – http://nutriag.com/article/mulderschart and recommends you get your soil tested and then check the chart to see the deficiencies and abundances in the nutrients and minerals content and the relationship between the variables.