Sneaking in here late! Hi guys!
Class this week was on SOIL. I learned so much! I’ve heard many of you speak about it here on the thread, so I wasn’t completely at sea. I thought what I would try to do is to type up my notes so in later years I can read my hen-scratch, and in that process, I would share at least some of them with you.
Our presenter is a professor at OSU in the soil department. That is where the soil tests are done in our state through the county ag programs. He is from China and has been here in Oklahoma for almost 20 years. Excellent English and teaching approach. We all really liked him!
I hope these are useful to you!
Have a very blessed Easter weekend!
texokie
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4/2/15
SOILS – Hailin Zhang
Soil and Nutrient Management
Difference between “soil” and “dirt?” Dirt is the stuff beneath your fingernails. Soil is feeding a plant.
Analogy: Soil is like the foundation of a house. It is fundamental to everything else working well.
EFFECTS OF SOIL
Soil can affect things like if basements are built in an area. In areas with heavy clays, you will see fewer basements because the heaving of the clay will cause the basements to crack. In areas with other materials, you will see basements very commonly.
An example of how soil can affect things is the example of a plant with lots of lush leaves with no fruit. One thing to think of in that situation is that there may be too much nitrogen in the soil.
If you know how to manage soil, you can have a good harvest.
He showed us pix of his garden. Lots of wonderful Chinese veggies.
He showed us his loofah gourds. They looked like cucumbers.
[Texokie note: He stated he and his family eat them. I had not heard of this. Did a search and here is a representative link: http://globaltableadventure.com/2010/07/08/technique-thursday-how-to-prepare-and-eat-loofah/ ]
He had pix of a 15 lb Chinese cabbage! They had only a few of them, and would harvest only a few leaves at a time so they had it all the time.
CLIMATE
He discussed climate a bit. He said you need to know what plants like your climate. Remember there are microclimates as well and the larger general area climate.
He said that Bok Choy does well with cold, but in the cold part of the Oklahoma winter, he just covers it up, and somehow they last longer in the winter. He is also able to grow daikon radish here. Must have good soil deep enough to accommodate the root.
PLANT REQUIREMENTS
Plants need a number of things including [but not limited to! – Texokie missed some of these!]
Soil, nutrients, sun light…
Lawns and flowers – need proper soil and fertility of soil too! Otherwise, you get weeds, and your lawn and flowers are actually more difficult to tend. So, having good soil helps cut down on work.
INFLUENCES ON PLANT GROWTH:
[Texokie DID get these!] Some of these you can’t do anything about. We manage what we can:
Air Temp Light Mechanical Support Nutrients Water
BASIC SOIL SCIENCE (LOL! NOT DIRT!)
WHAT IS SOIL?
Showed pic of a cross section of a cut in a field. Plants on top. About 2 feet of black soil full of organic matter. Beneath that is a layer of hard pan. The plants growing above this soil are very healthy and happy. He noted that the pic had been taken in Minnesota. Humus decomposes very rapidly in Oklahoma, while the organic matter soils in cooler areas do not break down as quickly, and so can build up like this.
SOIL DEFINITION:
Unconsolidated cover of the earth, made up of mineral and organic components, water and air and is capable of supporting plant growth.
12 DIFFERENT SOILS PROFILES IN THE WORLD which each have unique physical, chemical, biological, properties
The factors used to define these profiles involve color, texture, structure, consistency, roots, pores, other features.
Oklahoma has 8 out of the 12 of the distinct soil types. Some of these not in Oklahoma exist in places like Hawaii with a lot of volcanics. He did not specify the other 4 or the areas in Oklahoma of the diffent types.
SOIL FORMING FACTORS:
Climate, organisms, topography, parent material, time
He glanced over some of the processes, but not I great detail. Mentioned some of these factors being represented by such things as alluvial sediments, rocks, etc. He noted that soil bldg. is a long process. We need to protect our soils. While he did not mention it, the Dust Bowl in Oklahoma in the 20s and 30s came to my mind. It took a while for areas of good soil to build back up again.)
This is the end of the first installment on SOIL.
SOIL IS A DYNAMIC SYSTEM
Soil building is a dynamic process. It takes time to build a good soil. These are the processes involved in soil building:
*Addition – roots etc /decomposition/bacteria and other microbes
* Removal – lose surface from storms, lose nutrients from plants
* Transformation – rocks will break down sand silt clay
* Translocation - [I didn’t have anything in my notes here. I am presuming is something like the processes of streams, flooding – but I’m not certain – basically I take it to mean things are moved and must be slightly different in meaning to the addition and removal processes. TXO]
COMPOSITION OF SOIL He showed a pie chart graphic with the following percentages:
*Water – 25%
*Air – 25% He said, “You don’t want to lose your air!” He noted that too much water will take away the air.
*Minerals – 48% These are the sands, silts, and clays.
He showed us an inset graphic showing the relative amounts (no numbers) of those components of the 48%
Imagine here a circle about a nickel size: SAND
Imagine here a circle about .5 cm: SILT
Imagine here a dot: CLAY . . . . [Except for TEXOKIE’s yard! LOL!]
*Organic Matter – 2% He noted that the Minnesota pic shown earlier with the 2 feet of fertile black soil was about 5% of organic matter. The farms in Oklahoma can be 1%. We need to do our best to increase that percentage to the 2-4% and that puts us in a good soil range.
A student asked about lime addition. He said that the question anticipated him, but that it is for the neutralization of the acids in the soil. He said that taking abundant samples and testing them will help in learning what amounts to use to make that amendment.
SOIL PROPERTIES
* TEXTURE – relative proportion of the grain sizes
* STRUCTURE – arrangement of particles into small groups, or aggregates
Texture and Structure are PHYSICAL PROPERTIES, and those are difficult to change.
*FERTILITY – how nutritious is the soil for supporting plants
*pH - soil acidity and alkalinity
*SOLUBLE SALTS – sodium, chloride, but also other mineral salts as well can precipitate / leach out of the soil depending on what minerals are present.
[TXO’s thought of an example: In limestone areas, can get calcium salts (travertine) – that is certainly common in our area! Ground water is full of it – so it’s in the soil too!]
Fertility, pH, and Soluble Salts are all CHEMICAL PROPERTIES and actually ARE things we can change.
*BIOLOGICAL – microorganism populations and other life in the soil. This includes bacteria, worms, fungi, etc.
He had a triangle graphic showing the different types of soils. I got most of it, but cannot really reproduce it here.
SOIL TYPES Imagine a triangle with the base having the caption :
SAND %
The left ascending leg has an arrow pointing up to the top:
CLAY %
The right leg has an arrow pointing downward to the base with the caption:
SILT%
Arranged inside the triangle showing the appropriate percentages are the various kinds of soil such as “Clay, silty clay, silty clay loam, sand, mixtures of sand and clay and silt [which TXO missed] and loam [the sweet spot in the middle], sandy clay loam, sandy clay, clay loam.” He wasn’t so concerned that we get the exact percentages, just that we see the principle of that range of the kinds of soil you get with the three ingredients, sand, clay, and silt.
APPROXIMATION OF WATER HELD BY THE DIFFERENT SOILS:
SOIL TEXTURE: SAND
has the water holding capacity in .5-.7 inches/foot of soil
has the rate of irrigation of .75 in inches/hour; bare soil
SOIL TEXTURE: LOAMY SAND
Has the water holding capacity of .7-1.1 inches/foot of soil
Has the rate of irrigation of .75 in inches/hour; bare soil
SOIL TEXTURE: LOAM
Has the water holding capacity of 1.0-1.8 inches/foot of soil
Has the rate of irrigation of .35 in inches/hour; bare soil
SOIL TEXTURE: CLAY LOAM
Has the water holding capacity of 1.3-2.1 inches/foot of soil
Has the rate of irrigation of .25 in inches/hour; bare soil
SOIL TEXTURE: CLAY
Has the water holding capacity of 1.4-2.4 inches/foot of soil
Has the rate of irrigation of .15 in inches/hour; bare soil
Installment 2 on SOIL ends. Again, Have a Happy (Remaining) Easter, yall!