This is a summary of International Ag Labs weak-acid soil testing (per Carey Reams) and what test results they're looking for.
Soil Testing
Humus Testing: Humus is different from organic matter. The organic matter measures both inactive and active organic matter. The humus reading is just the active organic matter. Active organic matter is already broken down and usable by the plant.
Nitrate Nitrogen: The nitrate nitrogen is the bulking of the two types of nitrogens. If you want to bulk a plant or produce you want use calcium nitrate or potassium nitrate.
Ammonia Nitrogen: The ammonia nitrogen is the seed producer of the two nitrogens. If you want what you’re producing to have seed, you want ammonia nitrogen.
Nitrogen is one of the most important nutrients needed to grow anything. Nitrogen is key in building plant amino acids which plays a part in plant protein and enzyme production. The proteins and enzymes are used in the chlorophyll, grain production, plant tissue for growth and development, and in the roots helping with food and water uptake.
Phosphorus: All nutrients go into a plant in phosphorus form except nitrogen. I know people don’t believe, but it does. When you look at the atomic charge of a plant cell it is positively charged. Phosphate is naturally negatively charged so it will be drawn naturally into the cell. Phosphorus is extremely important in a plant’s nutrient uptake with how much it is used in the photosynthesis process being the main part of the plant energy production.
Potassium: Potassium is needed for enzyme functions, proteins, food transport, chlorophyll production, and is used in enzyme activation within the plant. If your soil is low on potassium, you should use 0-0-50 potassium sulfate. Avoid using potassium chloride 0-0-60, since it has a high salt index.
Calcium: Available levels are very important in growing high quality. Calcium is important for cell division, root hair growth, enzyme function, and normal cell walls. Calcium improves plants resistance to disease and gives higher quality and more nutritious crops. Also, calcium only flows through the xylem of a plant so it can only travel in one direction.
Magnesium: Magnesium is the center of the chlorophyll molecule and is key in enzyme activation. You need to make sure that your calcium: magnesium ratio is at least 7:1 or at the most 10:1.
Sodium: Your sodium levels should be less than 35 ppm. If its higher than that the soil will dry out to fast, and it will take a lot more water to grow a crop. If you have high sodium levels, you can use gypsum to help lower sodium levels.
Ergs: Ergs is an electrical conductivity of the soil. You should have 200 ergs in your soil. The sodium can have influence on the Ergs reading. If your Ergs reading is high, you can have issues of your soil drying out faster much like how high sodium levels would.
Oxygen Reduction Potential Testing: (ORP) This is the reading for how oxygenated your soil is. 28 is the ideal reading for ORP. If the ORP is less than 28 you must put on gypsum to help relieve the compaction. If ORP is above 28 you are oxidizing your organic matter into the air.
pH Testing: This basically is a measure is a measure of hydrogen ions. If the pH is above 7 it will be alkaline or basic if it’s lower than 7 pH, it’s acidic.
Copper Testing: Should be .8-2.5. ppm. Copper is nature’s fungicide. In some of the fungicides today they have small amount of copper in them. It also helps with enzyme activities in the chlorophyll and seed production. Copper can also be useful for cell wall flexibility due to its help in lignin production.
Iron Testing: Should be 10-50. Ppm. Iron in plants is used the same way in iron as in our bodies helping transport nutrients through the organism. Also, it is used in the creation of chlorophyll and helps maintain the chloroplast function and structure.
Zinc Testing: Should be 1-6. ppm. This nutrient is a big part of auxin formation which is a growth regulator and stem elongation. Also, zinc is used in the formation of chlorophyll and some carbohydrates plus helps converts starches into sugars.
Manganese Testing: Should be 10-50. ppm. Dr Skow said that manganese was the element of life. It took manganese to produce the offspring to sustain life. One big usage of this nutrient is it splits the water molecule inside the cell. It also plays a factor in reproduction by helping pollen germination and pollen tube growth. You can see root cell elongation and root pathogen defense as well. In the soil healthy bacteria need this nutrient to do specific process and if it is not available this will hinder them affecting everything they do in your soil.
Boron Testing: Should be .8-1.2 ppm. This nutrient even though we only need small amounts it plays a big role in cell wall and cell membrane strength and formation. Along with cell wall and membrane function this nutrient also helps move sugars to new growth of the plant, helps with pollination and seed setting, along with helping biological membrane integrity.
Sulfur Testing: Should be 30 ppm. This nutrient is key in the formation of amino acids, proteins, and plant oils. It will play a factor in build chlorophyll, nodules, enzymes, vitamins, and amino acids.
Organic matter Testing: Should be 4%. This will show the total of usable and non-usable organic matter where humus is just the usable organic matter. Organic matter is large part of retaining moisture in your soil.
Formazon Testing: Should be 600 ppm. Formazon is a snapshot of the microbial life and activity of your soil sample.
Cobalt Testing: Should be 1 or 2 ppm. This nutrient will help create enzymes in a plant plus help with drought stress for the seed. It will also help the bacteria for nodulation.
Molybdenum Testing: Should be .25-0.50 ppm. This nutrient help make nitrate nitrogen transition to a usable form for plants. It also can help with the usage of different phosphorus forms. At higher levels you will not see much for plant toxicity, but 5-10 ppm can cause toxicity in ruminant animals
Nickel Testing: Should be 3-450 ppm. Nickel can be used to help the enzymes used within legumes for nitrogen fixation and it helps make ammonia nitrogen more usable.
Our normal soil sample consist of Humus, nitrogen, phosphorus, potassium, calcium, magnesium, pH, O.R.P., Ergs, Copper, Iron, Manganese, and Zinc. The other nutrients are separate test and will need to be requested if you would like them done. Also, if you are wanting Nickel, Cobalt, and Molybdenum you may have readings of zero because if you have not either placed them there by fertilizing, or had mining or smelting on or around your area you will not have any in your soils.