Trends in Soil Management for Turf David C. Smith P.Ag DCS Agronomic Services
Points for Today s Discussion Soil Testing Considerations Soil test interpretation How water moves in the soil Recommendations for Turf
The Only Thing That Never Changes is Things Keep Changing
OMAFRA Publication 611 Soil Fertility Handbook Turfgrass Soil Fertility and Chemical Problems Carrow, Waddington & Rieke
Golf Course Management - Research Clarifying Soil Testing 1 Sept. 2003 Clarifying Soil Testing 2 Jan. 2004 Clarifying Soil Testing 3 Jan. 2004 By: R.N. Carrow, L. Stowell, W. Gelernter, S. Davis, R.R. Duncan and J. Skorulski
PACE Turf http://www.paceturf.org/ Owned and managed by: Larry Stowell Ph.D. and Wendy Gelernter Ph.D.
Balance What is a balanced soil?
Soil Balance Chemical Fertilizers, Lime Pesticides,pH CEC Cations Anions Physical Texture, Structure Compaction, Hardpan Porosity Biological Bacteria, Fungi, Algae Actinomycetes Protozoa, Earthworms
Soil Components ORGANIC MATTER (5%) WATER (25%) MINERAL (45%) AIR (25%)
Mineral Uptake Mass Flow
Air and Gas Exchange Most abundant elements in plants Not applied as fertilizer Carbon (45%) Hydrogen (6%) Oxygen (45%)
Differences in Mobility of Mineral Nutrients in the Phloem Nutrient High Mobility Intermediate Mobility Low Mobility Calcium X Manganese X Iron X Silicon X Copper Zinc Boron Sulfur X X X X Molybdenum X Chlorine amino-h Sodium Nitrogen Phosphorus Potassium Magnesium X X X X X X X Data from Pages 14-15 of Turfgrass Soil Fertility and Chemical Problems
Soil Sampling Critical to development of successful nutritional, irrigation and soil management program Soil / Plant / Thatch Inspection?
Soil Sampling for submission to lab Number of samples (probes) Boundaries of sampling areas Depth of samples Time of sampling
Soil Testing at the Lab Why so confusing? No defined system of analysis or reporting of data due to different labs specializing in different soil location and various crops
ph Measurement of hydrogen ion activity or concentration in soil Generally done as a paste extract at a soil to ionized water ratio of 1:1 Influence on nutrient availability
ph
Buffer ph Determines the ability of a soil to resist change in ph Measured by adding buffer solution to soil and reading ph after one hour. Used to determine need for lime Charts available for making lime calculations
Soil testing Saturated Paste Extract (SPE) Nutritional Soil Audits (NSA) using chemical extractants to provide an estimate of nutrition available to plants over a defined period of time
Testing - Saturated Paste Extract (SPE) Developed by US Salinity Lab in 1954 to determine: Electrical Conductivity (ECe), Sodium Adsorption Ratio (SAR) Boron toxicity
Saturated Paste Extract Guidelines Saturated Paste Extract Guidelines Parameter Function Ideal ECe Measure of Soluble Salts <4 DS/M SAR Determine Na within or applied to soil and identify potential for problems <3 Calculation Boron Measure for potential Boron toxicity <2 ppm
Testing - Saturated Paste Extract (SPE) Compost sources may contain toxic levels of boron or salt content important to check before using for landscape plantings
Testing Nutritional Audit & Inventory Report Base Cation Saturation Ratio (BCSR) Conventional Sufficiency Level of Available Nutrients (SLAN) Minimum Levels for Sustainable Nutrition (MLSN)
Testing Nutritional Audit & Inventory Report Base Cation Saturation Ratio (BCSR) Determines percentage of cation saturation levels. Ca, Mg, K, Na & H. Requires accurate determination of the soils nutrient holding capacity for positively charged cations
Testing Nutritional Audit & Inventory Report Sufficiency Level of Available Nutrients (SLAN) and (MLSN) (SLAN) and (MLSN) systems developed to estimate quantity of plant available nutrition in the soil SLAN and BCSR if used correctly should compliment each other
Inductively Coupled Plasma Analyzer (ICP)
Extractants Approximately 1% of soils inventory of minerals are plant available Water first and simplest extractant - (SPE) More robust chemicals (extractants) required to determine soils nutrient inventory status Soil Audit and Inventory Report.
Extractant Options Nutrient Phosphorous Potassium Soil Medium Sufficiency Range (ppm) Medium Sufficiency Range lbs./a (P2O5) Extractant Nutrient Soil Medium Sufficiency Range ppm Medium Sufficiency Range lbs./a Extractant all 15 to 30 68 to 137 Mehlich I all 200 to 350 400 to 700 Mehlich I all 26 to 54 118 to 247 Mehlich III (ph 2.5) all 500 to 750 1000 to 1500 Mehlich III (ph 2.5) Calcium all 15 to 30 68 to 137 Bray 1 all 500 to 750 1000 to 1500 NH 4 OA c (ph 8.1) all 51 to 81 234 to 362 Bray 2 all 500 to 750 1000 to 1500 Morgan all 12 to 28 54 to 128 Olsen all 10 to 20 45 to 91 Morgan Sulphur all 10 to 20 20 to 40 Ca(H 2 PO 4 ) 2 all 30 to 60 60 to 120 NH 4 OA c (ph 8.1) sands 75 to 175 150 to 350 NH 4 OA c (ph 8.1) all 15 to 40 30 to 80 Mehlich III others 100 to 235 200 to 470 NH 4 OA c (ph 8.1) sands 50 to 116 100 to 232 Mehlich III (ph 2.5) sands 30 to 60 60 to 120 Mehlich I others 75 to 176 150 to 352 Mehlich III (ph 2.5) others 50 to 100 100 to 200 Mehlich I sands 50 to 100 100 to 200 Mehlich I sands 60 to 120 120 to 240 Mehlich III (ph 2.5) others 90 to 200 180 to 400 Mehlich I Magnesium others 70 to 140 140 to 280 Mehlich III (ph 2.5) all 155 to 312 310 to 624 Olsen sands 100 to 200 200 to 400 NH 4 OA c (ph 8.1) all 120 to 174 140 to 348 Morgan others 140 to 250 280 to 500 NH 4 OA c (ph 8.1) all > 100 > 200 Morgan
ph - influence
Extractants - Chemical Weak acids (acidic, citric, lactic,) and stronger acids (hydrochloric, sulphuric, nitric) Often two or more acids used together to extract multiple minerals
Extractants Mehlich III (ph 2.5) Developed by Dr. Adolph Mehlich to serve as a universal extractant for all soils Multi-element extracting solution composed of Acetic Acid, Ammonium Fluoride, Ammonium Nitrate and the chelating agent - Ethylene Diamine Tetraacetic Acid (EDTA) Considered dependable to ph of 7.3 Routinely used in Quebec and Maritimes
Extractants - Bray 1 Represents plant available P Designed for determining P requirements in acid soils Not recommended for alkaline soils with ph above 7
Extractants - Bray 2 Bray 2 phosphorus represents phosphorus considered plant available and about 10-15% of the unavailable -P. Not a lot of good calibration data is available. Designed for determining P requirements in acid soils Not recommended for alkaline soils with ph above 7
Sodium Bicarbonate (Olsen) Alkaline soils (ph 7.5) can affect the P extraction process in Mehlich III.-P and Bray II-P tests. Olsen-P test designed for high ph soils. Request Olsen-P test if the soil is alkaline
Extractants - Ammonium Acetate ph 8.1 Developed for extracting Mg, Ca, S and K, Well suited for use on alkaline soils ph >7
Extractants - DTPA Diethlylene Triamine Penta-acitic Acid (DTPA) Component of Mehlich III extractant Used alone for extraction of minor elements
Phosphorous Most complex in terms of soil chemistry Tends to balance nitrogen, hastens plant maturity, improves quality of fruit (Seed) and disease resistance Important that extractant match soil submitted for analysis - acid soil vs. calcareous soil
Potassium Important nutrient required for growth and stress tolerance Ongoing research to evaluate potassium requirements for turf Mehlich III and Ammonium Acetate two popular extractants for potassium determination
Calcium Required as a catalyst for many plant functions Values may be low in low CEC soils resulting in a need for limestone applications Mehlich III and Ammonium Acetate two popular extractants for calcium determination
Magnesium Part of chlorophyll molecule Important for photosynthesis and thus important factor in overall plant health enters in formation of proteins in plants and related to movement of carbohydrates from leaves to stems Mehlich III most popular extractant
Sulphur Important constituent for plant growth Functions in formation of proteins Number of extractants can be used for sulphur extraction Ammonium Acetate, Mehlich III and Calcium Dihydrogen Phosphate Ca(H 2 P04) 2
Minimum Levels for Sustainable Why MLSN? Nutrition (MLSN) Measurement sustainability Reduction in amount of fertilizer and inputs required for application of fertilizer Reduced environmental risk Global Soil Survey - ongoing
Soil Test Guidelines Conventional & (MLSN) Nutrient Analytical Test Conventional ppm (MLSN) ppm Phosphorous Olsen >12 >6 Phosphorous Bray 2 >75 >25 Phosphorous Mehlich 3 >50 >18 Potassium Mehlich 3 >110 >35 Calcium Mehlich 3 >750 >360 Magnesium Mehlich 3 >140 >54 Sulphur Mehlich 3 15-40 >13 Nitrate N KCL 3-20 1-10 Ammonium N KCL <7 0-7 Total N KCL <20 3-10
Micronutrients - ph Due to influence of ph on availability of minor elements values should not be considered absolute. Solubility index values for manganese, iron and zinc can be calculated from soil test data. Comparing plant tissue analysis values with soil test and solubility index values helps round out and validate the need for minor elements.
Micronutrients * In high ph soil - no good soil test for Iron Low side of CL High side of CL Low ph Low CEC High ph High CEC Consider impact of Mass Flow!
Micronutrient Micronutrient Method Critical Soil Level Range Boron Mehlich III 0.4 to 1.5 Hot Water 0.3 to 2.0 Iron * Mehlich III 50 to? DTPA 2.5 to 5.0 Manganese DTPA 2.0 to 5.0 Mehlich III 10 to 35 Copper DTPA 0.2 to 2.5 Mehlich III 0.6 to 3.0 Zinc Mehlich III 1.0 to 4.0 DTPA 0.3 to 2.0 Molybdenum Hot Water 0.1 to 0.25 > 8 may be toxic
Suggested Reading OMAFRA Publication 611 Soil Fertility Handbook Turfgrass Soil Fertility and Chemical Problems Carrow, Waddington & Rieke
Suggested Reading Golf Course Management - Research Clarifying Soil Testing 1 Sept. 2003 Clarifying Soil Testing 2 Jan. 2004 Clarifying Soil Testing 3 Jan. 2004 By: R.N. Carrow, L. Stowell, W. Gelernter, S. Davis, R.R. Duncan and J. Skorulski
Thank You David C. Smith P.Ag, CGCS DCS Agronomic Services 705 687-7645 dave@dcsturf.com