1.1.2 Optimal soil

There are numerous criteria which must be met to have optimal soil. In the other links within this site, emphasis is placed on nutritional tonic effects.

In my opinion, the presence of earthworms is a key indicator of soil health (although there can be no better measure than productivity, see inter alia the links describing HIBRIXTM^TM TONIC results on dairy pasture [Section 5.5] and on dryland wheat [Section 5.6] off the listing of various HIBRIX^TM results).

A discussion by Elaine Ingham offers some explanations for considering earthworms a key soil health indicator.

Apart from the absence of earthworms indicating the absence of sufficient tilth, moisture etc or presence of toxins, in Elaine's words :

1. The biggest (soil) organisms are most susceptible to compaction.

The biggest organisms tend to be the top of the foodweb, those organisms that keep the correct balance in the system.

When these organisms are lost, at least theoretically, the soil will switch from a fungal-dominated to a bacterial-dominated system.

When soil becomes dominated by bacteria, trees cannot grow.

2. As compaction continues, soil pore space decreases, killing the largest of the predators of bacteria and fungi.

Since fungal-feeding predators are larger than bacterial-feeding predators, fungal-feeding organisms are lost.

This means fungal biomass accumulates, preventing release of nutrients tied-up in fungal biomass.

Plants may suffer nutrient deficiencies, since nutrient cycling is blocked.

3. As compaction reduces soil structure even more, bacteria, protozoa and opportunistic fungi are about the only organisms that remain active in the soil. Roots and water have a difficult time moving into and through the soil.

Root -feeding nematodes and insects have no or few competitors.

When the soil wets-up, oxygen diffusion is limited since the soil pores are small and passage between them is limited.

These are perfect conditions for fungal pathogens to grow, since they too have little competition.

Bacterial growth continues, however, and anaerobic conditions can develop as oxygen diffusion is slowed.

Anaerobic bacteria produce metabolites which are extremely detrimental to root-growth, with direct impacts on plant production.

One can variously approach the rebuilding of soil; for example the garden soil-building advice of Marie Hofer can be adapted to just about any scale.

Myself, I consider four steps useful :

The first step is to build up carbon(*) - presuming it is under 2%. Try to get 4%, which is possible if your soil and climate are kind enough. Links off my site http://www.Plantsfood\Soils\optimalsoil.htm might offer useful advice for you.

Secondly, attempt to balance the soil elemental nutritional state, eg (approximately) according to Reams soil balance [ppm ex Morgan Extract(**), which equates to ppa (pounds/acre)/2] :

Ca : 1500
Mg : 125
P2O5 : 200
K2O : 100
N as NO3 : 25
N as NH3 : 25
SO4 : 70
Na : 20
Mn : 15
Fe : 20
Cu : 8
B : 2
Cl : 2
Co : 2
Net Plant Food Conductivity [ERGS] (***) : 350 microSiemens
pH(****) : 6.5
P2O5/K2O : 2 [crop] to 4 [gras]

Thirdly, remineralize the earth eg with rock dust, up to 2000 kg/Ha

Fourthly, consider using HIBRIX to promote soil formation and nutrient transfer - typical recommendations are give on http://www.plantsfood.com/tonics.htm

(*)Organic Matter (loss on ignition)

1) Weigh crucible and record. Add 5 - 10 gm soil and place in 110 C drying oven for a minimum of 2 hr.

2) Remove from oven and weigh as soon as it can be handled (while still warm) and record. Place in muffle furnace. Heat to 375 C and maintain temperature for 2 hr.

3) Remove, weigh crucible as soon as it can be handled (while still warm), and record.

Note: it is important that air-dried soils be oven-dried before ignition, since air-dried soils retain 1 - 4 % moisture depending on texture. If crucibles cannot be weighed while still warm, place them in a desiccator to avoid re-adsorption of moisture from the atmosphere.

Convert loss on ignition to Walkley-Black equivalent organic matter using the following regression equation:

Organic matter = 1.04 x % LOI - 1.0

(**) Modified Morgan Nutrient Extraction

1) Fill a standard 5 cc scoop heaping full, tap the scoop handle to settle, and strike off the excess, level with the top of the scoop. Weigh and record the scoop contents and empty into a 50 ml flask in shaker rack.

2) Add 20 (+/-0.2) ml pH 4.8 ammonium acetate (Modified Morgan) solution.

3) Shake on a platform shaker at 180 oscillation/min for 15 min.

4) Filter immediately through fast filter paper (Whatman 2 or equivalent).

5) Analyze filtrate for Ca, K, Mg, P, Na, Pb, Zn by plasma emission.

Modified Morgan Extraction solution (40 liter total volume)

Add to about 20 liters distilled or deionized water:

2875 ml concentrated glacial acetic acid

1825 ml concentrated ammonium hydroxide

Dilute to 40 liters total volume and mix thoroughly.

Adjust pH to 4.8 (+/- 0.05) with acetic acid or ammonium hydroxide.

(***) Net Plant Food Conductivity [ERGS]

ERGS (Energy Released per Gram Soil) is simply the conductivity (in microsiemens, µS) of a 1:1 soil/water slurry.

Low ERGS means no plant food. High ERGS dehydrates rootlets. ERGS is always NET conductivity, i.e., you subtract the residual conductivity in, say, a nearby fence row from the conductivity reading in the fertilized root zone.

Rex Harrill points out that the whole point of ERGS testing is to evaluate if there are adequate conductive plant food ions to feed the plant at the rate it wishes to be fed. Those who have watched a weed pull all the energy from the soil and stunt the crops next to it have watched the ERGS concept at work.

Further, anyone with a conductivity meter knows that salt can dramatically increase the conductivity of a water sample. You do not want to include salt values as ERGS. Thankfully, most salts are soluble and will flush out of a highly-alive soil readily.

Various Reams practitioners advise as follows with respect to ERGS :

Bob Pike suggests checking the conductivity of soils early in the spring before the soil microbes go to work. The E.C. obtained (residual salts) is then kept on record for that field and always subtracted later when one is making an ERGS test.

Dan Skow further suggests that you should review the Lamotte report of available plant food and discount any "ERGS" that show up when the soil tests show little or no 0-0-0 plant food.

To measure soil conductivity :

1. Use a small beaker or cup to measure out a fixed volume of soil. Do not pack soil into cup, but fill any voids of > 1/4" diameter. Fill cup to brim & remove excess with a clean straight edge.

2. Pour into a larger jar or cup with a lid.

3. Measure an equal volume of low conductivity (i.e., less than 5µS) distilled water. Pour into jar or cup.

4. Cover the jar. Gently shake contents back and forth 5 - 7 times to partially put into solution the ions that are loosely bonded to soil particles or humus molecules. Allow soil to settle to bottom of cup. The goal is to extract those ions that would be most readily available to the plant rootlets.

5. Place a few drops of the filtrate onto the sensor of the calibrated EC meter (alternately, immerse the sensor end of the meter into the liquid, being careful not to immerse beyond the level indicated). Turn on the meter and wait for the reading to stabilize.

6. Rinse the sensor with flowing stream of tap water. Spray rinse with distilled water. Several rinses may be required in order to obtain reading of < 1 µS with good distilled water.

(****) Soil pH (water)

1) Weigh 5 (+/- 0.02) gm soil into a paper portion cup.

2) Add 5 (+/- 0.2) ml distilled water, stir, let sit 30 min. Measure pH to nearest 0.1 units using single junction pH and reference electrodes and pH meter.

Note: Calibrate apparatus with pH 4.0 & 7.0 buffers. Calibration should be verified, at a minimum, every 60 samples.

This remainder of this page relates to the SOIL CLASSIFICATION BASED ON MICROBIAL ACTIVITY as developed by the ASIA-PACIFIC NATURAL AGRICULTURE NETWORK [APNAN] ASIA-PACIFIC NATURAL AGRICULTURE NETWORK [APNAN].

Disease-Inducing Soil

The percentage of Fusarium in all fungi is high (more than 15 - 20%) in this soil. When raw organic matter containing high nitrogen is applied, this soil produces a foul odor. Maggots develop in the soil together with many harmful insects. Pest and disease infestation is high with significant damage to the crops. Therefore, applying raw organic matter is harmful for crops in this soil. Application of raw organic matter hardens the soil. The soil physical conditions deteriorate. In case of rice fields, gas is generated. Application of high quantities of chemical fertilizer and/or agricultural chemicals leads to the development of this type of soil.

Disease-Suppressive Soil

Micro-organisms, which produce antibiotic substances, exist in this soil. Thus, soil borne diseases do not develop easily. As Micro-organisms such as Penicillium, Tricoderma, Streptamyces are active; the percentage of Fusarium in all fungi is low (less than 5%) in this soil. When raw organic matter containing high nitrogen is applied to such soil, foul odors do not develop. The soil has the fresh sweet smell of mountain soil after decomposition. Soil aggregation and permeability are improved. On cultivation, pest and disease infestation is very low, but the yield is not so good. If this soil links up with a "Synthetic soil", productivity is enhanced.

Zymogenic Soil

This soil primarily contains zymogenic micro-organisms such as lactic acid bacteria and yeasts. When raw organic matter containing high nitrogen is applied, this soil develops an aromatic fermented smell. The populations of fermentable fungi such as Aspergillus and Rhizopus are increased. The percentage of Fusarium in all fungi is low (less than 5%) in this soil. The water-stable soil aggregate is high, and the soil becomes soft. Thus the solubility of inorganic nutrients enhances. The presence of amino acid, sugars, vitamins and other bioactive substances increase in this soil, thereby promoting crop growth.

Synthetic Soil

This soil contains micro-organisms such as photosynthetic, nitrogen fixing bacteria. Under stable soil moisture conditions, the soil quality is enhanced by addition of small volume of organic matter. The percentage of Fusarium in all fungi is low in this soil. This soil often links up with a "disease suppressive soil"

Balanced Zymogenic-Synthetic Soil

When "Zymogenic-soil" and "Synthetic soil" are linked, they becomes ideal soils for crop production. Such soil is termed "Zymogenic-Synthetic soil".

HIBRIX^TM MICROBIAFOOD offers a full and balanced spectrum of food supplement for all such microbes. It has been developed from inter alia a consideration of culture media used for selected microbes in academia.

Frank Pownall : Sales & Marketing
FAX : +61 8 6380 1499 TEL : +61 418 364 880 EMAIL : frank@plantsfood.com

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