The
Problem with Western Soils in Agriculture and in Urban Landscaping: Here's a Solution
Water is a growing
concern in the arid West and it's a problem that will never go away. This
paper addresses two situations that contraindicate the efficient use of water in
both urban landscaping and in agriculture, particularly where irrigation is
essential.
Soil Compaction:
The first problem
I'll cover is the compaction of soil.
This prevents water from penetrating
to an adequate depth, allowing roots to also grow deep, therefore providing
plants with a greater contact zone with soil, where water and element nutrients
can be found and sequestered. Compaction
also causes a problem with roots rotting due to the soil being airless
(anaerobic). Like us, roots and the
beneficial microbes of soil need oxygen in order to survive and function
properly, so compacted soils limit the functionality of roots and all the
beneficial soil microbes. Soils can also
be made anaerobic by amending them with organic matter that easily decays. This happens because the process of decay
consumes oxygen rapidly causing the soil to spoil as it turns anaerobic. Adding organic matter to either water or to
soil increases the BOD (Biological Oxygen Demand) caused by the microbes of
that environment attempting to break down the caloric value of the organic
matter, which requires oxygen. If the
soil is extremely porous, providing rapid water percolation, then high soil
organic matter is not a big deal, but in compacted arid region soils where the
soil is collapsed, dispersed and compacted, it may not be a good idea to amend
the soil with compost, peat moss, animal manure or other forms of easily
decayed organic matter.
Soil Salinity:
The second problem
limiting plant health is the increasing salinity of both our soil and our water,
a problem across all western regions of agriculture and urban areas where
fossil water or effluent water is used for irrigation. Soil also becomes increasingly saline (salty)
because high analysis acid based fertilizers are often used. Fertilizers
have a salt index, meaning they contribute salt to the soil! So soil salinity increases because we
irrigate with water that can be saline, or high in TDS (total dissolved
solids), we have high evaporative loss of our soil water, and our soils are
often compacted, preventing us from flushing the salt out of the soil by
irrigating with lots of high quality water.
And in areas where waste water effluent is has been implemented it’s causing
major salinity accumulation which can only cause a bad situation to get worse. Western soils are vulnerable to salinity
accumulation because our water quality is not excellent and our evaporation
rate is high, so the longer we irrigate and the longer we fertilize the greater
the soil salinity becomes! As times
continues the practice of irrigating with poor quality water and fertilizing
with high salt index fertilizers, we shall first experience the symptoms of
salinity by seeing the burning or dehydration of the foliage, and we shall see
the collapse of the soil caused by the dispersal of the soil clay particles as
the salt accumulates. This increases the
compaction of the soil! Dispersal of clay is literally a collapsing of
the structure of the soil causing it to seal, become hard and anaerobic, and
inhibits water percolation. In addition,
salinity will also inhibit water uptake into the plant as water will move in
the wrong direction trying to equalize the concentration of dissolved solids in
the liquid. If the concentration of
dissolved solids (salts) is greater in the soil water than it is in the plants
vascular water then water will leave the plant and go into the soil, attempting
to equalize the concentration gradient of the water.
The symptoms of dispersed
collapsed soil are easy to diagnose by simply probing the soil to see how hard
it is. You can use an inexpensive moisture
probe for doing this. A photo provided
in this paper shows a moisture probe used by a Phoenix Arizona Landscaping Co., which has been monitoring a park
sports field turf area in Phoenix after using the Soil Secrets products, TerraPro and EndoMaxima. TerraPro is a
unique formulated product made by Soil
Secrets which contains a bio-identical "organic matrix" of Humic
molecules that function as supramolecular.
Because they have this molecular characteristic they are capable of
assisting plants with water uptake, even under saline conditions. They are also capable of helping the soil
particles re-arrange, un-compact and form a macro-aggregate structure. When TerraPro is applied on a turf area such
as a sports field or golf course, even when high percentage Nitrogen,
Phosphorus and Potassium fertilizers has been used, you will often see the
performance of the grass improve. This
is probably due to the improved water uptake into the vascular system of the grass
and since water is an essential part of the chemical equation of
photosynthesis, the grass gets greener.
Phoenix
Arizona Landscaping Co., water savings demo project on a park sports
field. You can see that the right hand side of the field is noticeably greener
than the left hand side. Photo was taken 2 months after treatment with
both TerraPro and EndoMaxima mycorrhizal inoculant.
The image of the soil moisture probe picture
is about 4 1/2 months after the treatment in January of 2014. On the TerraPro treated side of the field the
moisture probe was easily pushed 6 inches into the ground. On the non treated side, the probe would not
penetrate more than a half inch before bending the probe. The results of this test have convinced the company
to invest in a larger commercial probe for continued testing.
Field on the right
was treated with the Soil Secrets TerraPro product and salinity damage was
decreased.
The photo below shows the treated field on the left and the control untreated field on the right. The reddish tinge on the right hand side untreated field is the burning of the foliage from the salinity!
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