2Healthy Soil Performs Five Vital Functions: Regulates water - Soil helps control where rain, snowmelt, and irrigation water goes. Water and dissolved solutes flow over the land or into and through the soil.Sustains plant and animal life - The diversity and productivity of living things depends on soil.Filters potential pollutants - The minerals and microbes in soil are responsible for filtering, buffering, degrading, immobilizing, and detoxifying organic and inorganic materials, including industrial and municipal by-products and atmospheric deposits.Cycles nutrients - Carbon, nitrogen, phosphorus, and many other nutrients are stored, transformed, and cycled in the soil.Supports structures - Buildings need stable soil for support, and archeological treasures associated with human habitation are protected in soils.
3Why We Need a Soil Analysis To determine the level of nutrients found in a soil sampleAccurate account of nutrient removal and replacementCrop production statisticTo manage fertilizer applications
4A soil analysis is only as good as the soil sample submitted A soil analysis is only as good as the soil sample submitted. * Sample problem areas and good areas * Sample different soil types * Sample for different crops * Use appropriate sampling techniques - probe 6” to 7” for tilled soil - probe 4” for untilled soil - minimum of 1 sample per 20 ac.
5First Principle - Feed the soil and let the soil feed the plant. Second Principle – The fertility level we are working to achieve is the right amount of each nutrient. (Soil Balance)True soil balance means determining and adding the proper amount of each nutrient.
6Fertilizers must have a positive charge to be held to the soil colloid. Positive charged elements are called cations.Colloids come from clay and organic matter and carry a negative charge.Negative sites on a clay particle will attract and hold positives.
7Negatively charged elements such as nitrogen, phosphorus, and sulfur are called anions. Negative ions do not hold to the clay colloid and remain free to move in the soil solution or water.
8The first thing to do for your land is to correctly measure the amount of clay and humus the soil has in it.That measure is – cation exchange capacity, or CEC.CEC is a measure of the capacity of the soil to exchange nutrients or “holding power”.A CEC of 10 will hold twice as many pounds of nutrients as a CEC of 5.
9Soil FertilityFirst: You must know the total exchange capacity (capacity of soil to hold plant nutrients)< Low CEC Sandy Soil15 – 25 or Ideal CEC> High CEC Clay Soil
10Cation Exchange Capacity What this means for us?High levels of one nutrient can affect the uptake of another nutrientExample:Too much calcium in a soil can limit the uptake of potassiumToo much potassium can limit the uptake of magnesium even if magnesium levels in the soil are high.
11Soil FertilitySecond: The base saturation percent (Specific % of nutrients needed for optimal plant growth)What the soil is composed of in terms of cations – calcium, magnesium, potassium, and sodium)Also tells the availability of these nutrients to plantsAn excess of any one of these four makes it “the weakest link in the chain”
12Soil Fertility Ideal for Ca & Mg is total 80% Clay soils need more Ca, sandy soils need more MgCation Calcium should be 60% to 70%60% in sandy soils70% in clay soilsCation Magnesium should be 10% to 20%20% in sandy soils10% in clay soils
13Yield and quality are determined by the percentages, not the pounds. Calcium 60 – 70%Magnesium 10 – 20%Potassium 3 – 5%Hydrogen 10 – 15%Other Bases 2 – 4%
14Nutrient ImbalanceToo much Calcium ties up all other nutrients (every other nutrient has to ride over the back of Ca to get to the plant).Too much Nitrogen ties up Calcium and other elements; even Zinc.Too much Phosphorus ties up Zinc and Copper.Too much Potassium ties up Boron.
15pH pH refers to how acidic or alkaline the soil is. pH – potential HydrogenRange of 0 to 14 with 7 as neutralA change of one unit in the pH scale represents a 10-fold change in acidity or alkalinity
18pHGlobal variation in soil pH. Red = acidic soil. Yellow = neutral soil. Blue = alkaline soil. Black = no data.
19LimeLimestone is the most effective and inexpensive aid to adjust soil pH.Dolomitic limestone – magnesium and calciumCalcitic limestone – calcium
20Lime Calcium influences pH, as does magnesium, potassium and sodium. Lime increases microbial activity, manages decomposition and overcomes the potential for Ca and Mg deficiencies.
21The pH will adjust to the proper level when all nutrients are corrected. Any nutrient required takes precedence over pH. When all nutrients are balanced, the pH will be right.As Ca concentration increases, it takes less nitrogen, phosphorus and potassium to do the same job.Every other nutrient has to ride over the back of calcium to get into the plant.
22Organic MatterSoil microorganisms decay organic matter and cycle nutrients back into forms that plants can use.The valuable link between soil carbon and your crop are soil microorganisms.OM effects nutrient cycles by chelating (chemically holding on to) nutrients, and preventing them from becoming insoluble and therefore unavailable to plantsWithout microbes, vital soil nutrients like Phosphorus remain present but unavailable to your crop.
23Organic Matter Enhanced development of soil aggregates Increased pore spaceIncreased infiltration and percolation ratesIncreased water holding capacityand…Organic matter is anything that once was alive. Bacteria, fungi, insects, and earthworms (among other creatures) use fresh organic matter as food. Their digestive processes convert the fresh residue in humic substances and nutrients. The nutrients in fresh organic residue are largely unavailable to plants before this conversion.The organic matter ranges from very simple to very complex chemical compounds. These includes sugars, starches, carbohydrates, nucleic acids, etc.Living organisms are also included in organic matter considerations.Increasing organic matter enhances the nutrient providing capacity of a soil and enhances its ability to function as a rooting environment.Organic matter is lowered by over-cultivation of natural soils. Management changes and additions are often needed to optimize productivity of over-worked soils.REVIEW: Is increasing organic matter in soils desirable?
24Organic Matter Greater capacity to hold and release nutrients Nutrient storageImproved cultivation ease (tilth)Promotes further biological activityOrganic matter is anything that once was alive. Bacteria, fungi, insects, and earthworms (among other creatures) use fresh organic matter as food. Their digestive processes convert the fresh residue in humic substances and nutrients. The nutrients in fresh organic residue are largely unavailable to plants before this conversion.The organic matter ranges from very simple to very complex chemical compounds. These includes sugars, starches, carbohydrates, nucleic acids, etc.Living organisms are also included in organic matter considerations.Increasing organic matter enhances the nutrient providing capacity of a soil and enhances its ability to function as a rooting environment.Organic matter is lowered by over-cultivation of natural soils. Management changes and additions are often needed to optimize productivity of over-worked soils.REVIEW: Is increasing organic matter in soils desirable?
25Organic Matter Five Ways Organic Matter Resists Soil Compaction Surface residue resists compaction. It acts like a sponge to absorb weight and water.Organic residues are less dense than soil particles.Roots create voids and spaces for air and water.Roots act like a biological valve to control oxygen in the soil.Roots supply exudates to glue soil particles together to form macro-aggregates and supply food for microbes.
26HumusHumus refers to any organic matter that has reached a point of stability, where it will not break down any further.Improves the structure of soil and contributes to moisture and nutrient retention.Humus can hold the equivalent of 80-90% of its weight in water.Allows soil organisms to feed and reproduce and is often described as the “life force” of the soil.
27Nutrient Functions Nitrogen Part of every living cell; important component of proteins, DNA, RNADirectly involved in photosynthesisNecessary component of vitaminsAids in production and use of carbohydratesWhy are these things important?Nitrogen helps make us what we are.DNA, RNAPhosphorus makes us happen.ADP-ATP: energy transferPotassium keeps us from falling down.Important for cell wallsREVIEW: Can plants live without N, P, or K?
28Nitrogen Has a negative charge and attracts a positive charge. Excess N causes weakness in the plant.Ties up copper and zinc.Takes either sodium or calcium as a passenger.For every % Ca taken out by N, Mg goes up 1%Anhydrous Ammonia (free ammonia) is toxic to living organisms and raises pH.
29Nutrient Functions Phosphorus Energy exchange Promotes early root formation and growthVital to seed formationIncreases water use and efficiencyHastens maturity
30Nutrient Functions Potassium Essential for plant growth Increases photosynthesisEssential to protein synthesisImproves quality of seed and fruitsImproves winter hardiness
31Nutrient Functions Calcium Continuous cell division and formation Reduces plant respirationIncreases fruit setStimulates microbial activity
32Nutrient Functions Magnesium Key element in chlorophyll production Improves utilization of PhosphorusActivator and component of many plant enzymes
33Sulfur 20 to 25 ppm minimum, 40 to 50 lb. of sulfur per acre. Adequate sulfur improves the palatability of any crop.Helps control excesses such as Mg and Na.Sulfur must move with water to carry excesses out.Ca must be >60% for sulfur to work.
35Sodium Anything above 3% is considered excess. Proper Ca/Mg saturation can compensate for higher saturations of sodium.
36Zinc Probably the most universally helpful of all the micro-nutrients. Instrumental in moisture absorption.6 ppm minimumPecans and other nuts are Zinc sensitive.
37Boron A minimum of 0.80 ppm is recommended. Increases N availability to the plant.Helps in nodulation of legumes.
38SummarySoil Analysis reports are an important tool in managing nutrient removal and replacement.A Healthy Soil has a healthy biological system.Organic Matter promotes further biological activity.Balancing soil nutrients is very important.Calcium is important to microbial activity.