This is the fourth installment in a series on plant nutrients and fertilizers.
(Part 1 is here.
Part 2 is here.
Part 3 is here.)

Many folks think about “fertilizing” their soil… which of course is a good thing. However, soil pH is a strong determinant of whether or not the nutrients in the soil are available to the plants.

Soil pH can also encourage or discourage disease.

What is pH?

pH is scored on a scale of 0-14. 0-7 is acidic; 7-14 is basic or alkaline.

Plants differ on their preference, tho in general, slightly acidic is best: 6.0-6.5

<>Primary and <>secondary macronutrients tend to be better available in more alkaline soils (high pH). <>Micronutrients tend to be better available in more acidic soils (low pH).

Soil bacteria and fungi are also influenced by pH. The optimal range for good soil bacteria is 6.3-6.8 (slightly acidic). Bacteria tends to multiply in a highly acidic environment. This leads to “souring” and putrefaction.

Essentially, when you soil pH is in the optimal range you’ll get bacteria action which fuels good decaying which makes nutrients available to the plant which allows healthy plant growth.

Testing pH

There are a number of home test kits on the market. You can likely find them in a decent size garden center. Here’s one available from Amazon.

Your pH can vary so you’ll want to test different areas/beds.

In general, areas with a lot of annual rainfall are more acidic, low rainfall areas tend to be near neutral (7.0). That doesn’t account for any treatments that have been applied

Correcting pH

Low pH or acidic soil: The quickest way to raise pH is to add a garden lime. You can also use crushed egg shells. Both lime and egg shells are primarily calcium carbonate. Garden lime is relatively inexpensive and already finely powdered.

As with any soil treatment, follow the quantity guidelines. You don’t want to over shoot and make your soil too alkaline.

High pH or alkaline soil: Sulfur will lower the pH. Again, be careful not to over apply and create a too acidic environment.

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This is the third installment in a series on plant nutrients and fertilizers.
(Part 1 is here.
Part 2 is here.)

There are eight micronutrients essential for plant growth and health. Their need varies with the plant. And their availability varies with the soil of course. Sandy soils and more alkaline soils tend to be more deficient.

The micronutrients are: Boron (B), Chloride (Cl), Cobalt (Co), Copper (Cu), Iron (Fe), Manganese (Mn), Molybdenum (Mo), Zinc (Zn).

Boron

Boron is important for plant cell division, metabolism and pollen germination. Deficiency is noted by cracked stems, stunted growth, brittle and discolored leaves, hollow fruit.

Chloride

Chloride is needed for osmosis and maintaining ionic balance which effects the plants ability to use water.

Chloride is seldom deficient and evidenced by wilting.

Cobalt

Cobalt aids the plant in using nitrogen. High nitrogen feeding plants are corn and legumes

Copper

Copper plays a role in forming plant cell walls and in converting amino acids to protein.

Deficiencies result in stunted growth and yellowed leaves.

Iron

Iron is involved in protein synthesis and chlorophyll synthesis. Naturally less chlorophyll = yellowed leaves. High Ph interferes with iron uptake so you’re more likely to see deficiencies in alkaline soil.

Manganese

Manganese activates enzymes used in forming chlorophyll. It also aids nitrogen metabolism. Deficient plants develop chlorosis – yellowing between the leaf veins.

Sandy soils, over-limed soils and high alkaline soils tend to be Manganese deficient.

Molybdenum

Molybdenum is essential for metabolizing nitrogen. It also aids in pollen formation. Unlike the other micronutrients, Molybdenum uptake improves with soil alkalinity. Deficiency results in irregular leaf formation.

Zinc

Zinc is involved in enzymes and metabolizing sugars. Thus, deficiencies result in stunted growth. Like the other micronutrients – except Molybdenum – alkaline soils are more zinc deficient.

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This is the second in a series on plant nutrients and fertilizers.
(Part 1 is here.)

Continuing on with our macronutrients. Today we’re featuring the secondary macronutrients: Calcium, Sulfur and Magnesium.

Calcium

Calcium keeps plants strong by keeping the cell walls strong. It’s also essential for cell division.

Generally farmers use dolomitic lime or gypsum to bump up the calcium.
Lime contains calcium carbonate which is very water soluble and easily leeches off.
Gypsum contains calcium sulfate which tends to have a low uptake.

And then there’s…
egg shells! Egg shells are 93% calcium carbonate. Sit them in the oven with the pilot light on for 10-20 minutes and they’ll dry. Then you can crush them into a powder form. If you want to be fancy, use a coffee grinder. If you want to be manual use whatever works to roll over them.

Spread the powder around the plants and water will take it into the soil. You can also soak the powdered egg shells in water and create a foliar spray

If you have a snail issue, crunch the egg shells up into small bits rather than powder. and spread them around your plants. Snails don’t seem to like crossing them.

Sulfur

Sulfur is important in chlorophyll formation which is responsible for vitamins, enzymes, amino acids and protein… critical to plant growth.

Sulfur is generally sufficient in reasonably good soil. Deficient plants will be a lighter green, more so in the upper part of the plant as sulfur doesn’t pull up the plant well.

Animal manures are a good organic source of sulfur.

Magnesium

Magnesium is central to the chlorophyll molecule. It’s an enzyme activator needed for photosynthesis, and hense, plant growth. It’s also a phosphorus carrier.

Deficient plants are lighter green and yellow between the leaf veins.

Dolomitic lime and Sul-Po-Mag are sources of magnesium. As is Epsom Salt. Epsom salt is more water soluble and works better as a foliar spray.

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This is the first in a series on plant nutrients and fertilizers.

When it comes to fertilizers you’ve probably noticed they’re labeled with 3 numbers such as 10-12-10. You may also see the letters N-P-K.
These are the periodic chart symbols for Nitrogen, Phosphorus and
Potassium.

The numbers are the percentage by weight of the three nutrients. So with the example above: 10% Nitrogen, 12% Phosphorous, 10% Potassium.
(Why don’t the numbers add up to 100?… there are fillers.)

By law, the product needs to be labeled with these nutrients and always in the same order: N-P-K.

Macro and micro-nutrients

There are 6 macro-nutrients.
Nitrogen, Phosphorus and Potassium are primary macro-nutrients.
Calcium (Ca), Sulfur (S), Magnesium (Mg) are secondary macro-nutrients.

Micro-nutrients include: Iron (Fe), Manganese (Mn), Boron (B), Copper (Cu), Molybdenum (Mo), Nickel (Ni), Chlorine (Cl), and Zinc (Zn).

Chemical (Inorganic) versus Organic fertilizers

Inorganic fertilizers are derived from, or with,
chemicals. They need to be water-soluble to be available to plants. A
consequence of this is once they’re dissolved in water, they’re vulnerable to evaporation, gasification and runoff.

To offset the losses, chemical fertilizers have a higher concentration of nutrients. Higher NPK values don’t necessarily equate to more plant nutrients.

The other issue with chemical fertilizers is the runoff which ends up in streams, lakes and ocean. High nitrogen runoff is credited for the large and growing algae dead zones in numerous bodies of water. Algae sucks up all the oxygen. Fish and sea life die.

With organic fertilizers, the “filler” is itself organic
material which also supplies micro and trace nutrients… everything is
used. Also, the nutrients are more slowly “released” to plants as they can use them.

Tho organic fertilizers have lower NPK values, the nutrients are more
completely used. So in the case – less is more.

Compost is about the best way you can feed your plants and keep the soil nutrient dense.

Other organic fertilizers include manures, worm castings, guanos, kelp, seaweed, blood meal and bone meal.

Organic fertilizers also are better soil aerators.

Nitrogen

Nitrogen helps plants produce more chlorophyll which in turn, promotes growth.

Few plants can convert atmospheric nitrogen so they need nitrogen in the soil.

Too much nitrogen and the plant will grow fast… but weak and disease vulnerable.

The form of nitrogen most frequently used in chemical fertilizers is
ammonium nitrate.

Phosphorous

Phosphorous supports root development and flowering.
It’s good to use with seedlings to get them established.

Chemical fertilizers generally use phosphoric acid/”triple super
phosphate”. This form can neutralize trace minerals in the soil.

Potassium

Potassium helps with disease resistance, extreme temperature tolerance and root development. It’s good to use during the winter (cold) and summer (hot).

Chemical fertilizers typically use Potassium Chloride or muriate of potash.

Potassium sulfate as a natural source of Potassium from the salt of The Great Salt Lake.

Plants aren’t all that different from humans in their need for nutrition. Where our best nutrition comes from broad array of fresh organic food, their best nutrition comes from nutrient dense organic soil.

Just as a plate of broccoli is a better, more available source of Vitamin C for us than a synthetically derived Vitamin C pill, so is organically fertile soil a better, more available source of N-P-K than chemical fertilizers.

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