Taking a Closer Look at Your Soil Report

Transcription

1 Taking a Closer Look at Your Soil Report Sarah Kenyon Agronomy Specialist (417) kenyons@missouri.edu Outline Taking a Good Soil Test Interpreting Your Soil Report Ag Lime vs. Pelletized Lime How to buy fertilizer Non-Traditional Fertilizers Tips to maximize your dollar 1 Sample 20 acres or less Cores 6 Inches Deep Place in a clean bucket and mix well Remove grass, sticks, and rocks Place about a pint of soil in a soil sample box & label Discard excess soil Get a Useful Sample 3 Sampling Tools Shovel or spade Soil probe Soil auger Timing of Soil Sampling Soil test data from one core is highly variable Avoid sampling soon after fertilization, liming, or manure application. Best to wait 3 months Sample every 2 to 3 years. Better to do a quality job (more cores per sample) less frequently Sample the same time every year. Avoid sampling within 150 feet of watering points, shade trees, gravel roads and other known hot spots Soil test P (Bray-I, lbs./acre) Mean: 44 STD: Core number 5 6 1

2 Accuracy can be increased by dividing fields based on known variability Soil test P (Bray-I, lbs./acre) Old manure piles Pasture Overall Mean: 44, STD: 48 Pasture mean: 20, STD: 17 Feeding area mean: 114, STD: Core number Feeding areas 7 Why test your soil? Avoid potential nutrient deficiencies Identify possible causes for poor pasture or hay production Save money $$$ Apply enough plant nutrients Avoid excessive expense A. Field info B. Soil test info C. Rating D. Nutrient requirements E. Cropping options F. Yield goal G. Pounds per acre H. Limestone suggestions I. Special notes phs salt ph H + ions in soil solution Indicates the level of active soil acidity Measured in a neutral salt solution Lower readings but repeatable phs 0.5 units lower than phw 9 10 Benefits of proper ph Increased efficiency of fertilizers Reduced availability of Al & Mn Favorable microbial activity Better soil structure Increased longevity of legume stands Improved activity of certain herbicides Improved availability of soil nutrients Ag Lime Lime is the most economical nutrient to apply Effective Neutralizing Material (ENM) Rates the effectiveness of the limestone Grinding limestone finer improves its solubility and speeds up reaction with soil Smaller the particle size, the faster the action (higher ENM) 11 2

3 Ag Lime Effective Neutralizing Material (ENM) To determine the amount of limestone needed in tons per acre, divide the ENM value on the soil report by the ENM guaranteed by your ag lime dealer 14 Ag Lime Effective Neutralizing Material (ENM) To determine the amount of limestone needed in tons per acre, divide the ENM value on the soil report by the ENM guaranteed by your ag lime dealer EXAMPLE: If the soil test ENM requirement is 1395 and the lime quarry guarantee is 420 pounds ENM per ton of limestone, then you will need 3.3 tons of limestone per acre ( ). Ag Lime Limestone is not very water soluble; therefore, it reacts slowly with soil May take as long as 1 year Incorporate limestone for more effective use Ag lime contains calcium carbonate, which is used to neutralize the ph Dolomitic lime also contains magnesium, and is used on magnesium-deficient soils Pelletized vs. Ag Lime Pelletized vs. Ag Lime $110/a $18/a Advertisements claim that lbs of pelletized limestone = 1 ton ag lime Pell-lime 1 ton/a Pell-lime 200 lb/a $11/a Ag-lime 1 ton/a Ag-lime and Pell-lime compared at equivalent effective rates on soil = ph 3.5 Each product compared at same effective rate, MU recommendation was 1209 ENM/a Ag-lime = 2.4 ton/a $43 Pell-lime =1.7 ton/a $187 David Dunn and Gene Stevens MU Delta Center 17 David Dunn and Gene Stevens MU Delta Center 18 3

4 Comparison of Cost and Effective Neutralizing Material (ENM)* of Ag Limestone With Two Sources of Pelleted Lime. % CCE lbs ENM/ton Cost/ton 1 Cost/lb of ENM lbs needed to equal ENM in 1 ton of ag lime Ag Lime $ Pelleted Lime $ #1 Pelleted Lime # $ *Limestone Quality Calculator 1 Spreading cost not included 19 ph at Harvest for Ag lime and Pell lime Treatments applied at equivalent effective rates Soil ph salt Ag Lime Pell Lime 2.0 0% 25% 50% 75% 100% MU Recommended ENM rate David Dunn and Gene Stevens MU Delta Center 20 Theoretical soil ph Adjustment High Soil ph Low Low rates of lime on very acid soils do not increase ph out of this range Low Lime Rate Each soil will have a different lime response due to buffering capacity differences When enough lime is applied to overcome the soil s buffering capacity, the soil ph increases rapidly per unit of lime then levels off. Some soils require much more lime to reach this point than others. High

5 Theoretical soil ph Adjustment 2 High Soil ph Low Low rates of lime on very acid soils do not increase ph out of this range Low Lime Rate Each soil will have a different lime response due to buffering capacity differences When enough lime is applied to overcome the soil s buffering capacity, the soil ph increases rapidly per unit of lime then levels off. Some soils require much more lime to reach this point than others. High 26 Soil ph Adjustment How Much Fertilizer do I Need? Soil ph 4.9 ENM Requirement 1390 West Plains Limestone ENM tons/a Springfield Limestone ENM tons/a Pellitized Limestone ENM tons/a How Much Fertilizer do I Need 3 numbers that describe N-P 2 O 5 -K2O A bag of diammonium phosphate will have the numbers on it it contains a minimum of 18% N, 46% P 2 O 5, and 0% K 2 O by weight The numbers do not add up to 100 percent, because fertilizers usually contain filler materials that help granule formation and assist with even product application How Much Fertilizer do I Need Material Analysis N (%) P2O5 (%) K2O (%) S (%) Ammonium Nitrate Ammonium Sulfate Diamonium Phosphate (DAP) Potassium Chloride (Murate of Potash) Potassium Sulfate Potassium Magnesium Sulfate Triple Super Phosphate

6 How Much Fertilizer do I Need In order to calculate a fertilizer application rate, you will need: 1. N-P 2 O 5 -K 2 O content of the material from the package label 2. Your target rate (normally from a soil test) 3. The total area you will be applying to 4. The density of the material if a liquid fertilizer is to be used How Much Fertilizer do I Need Example: Fertilizing Tall Fescue Hay Granular ammonium sulfate ( S) 60 pound N per acre. How much fertilizer is needed per acre? Answer: 60 lb N/acre 0.21 = 286 lb ammonium sulfate/acre How Much Fertilizer do I Need Example: Fertilizing with to tall fescue hay 100 lb per acre Soil report calls for 60 lb N per acre Is this enough fertilizer to feed the plants? Answer: 60 lb N/acre 0.19 = 315 lb/acre Useful Websites with Fertilizer Calculators University of Georgia University of Kentucky Useful Apps for Fertilizer Calculations Fertilize by Alabama Cooperative Extension Fertilize Cost Calculator Fertilizer Removal by Crop: by Ag PhD Effect of N source on fall growth of tall fescue at three Missouri locations DM Yield (lbs/a) * Mt. Vernon 05 Linneus Mt. Vernon 06 Columbia Location Am. Nit. Urea Am. Sulf. Urea + Agrotain Control No difference when applied in March N applied August 17 at 75 lbs/a Kallenbach

7 Liquid Fertilizer Units per gallon of Material N P 2 O 5 K 2 O Gallons to equal 50 lb N (10.1 ) % (11.1) % (10.6) Source: John Jennings, University of Arkansas Extension Liquid Fertilizers Yield (lbs DM/acre) Evaluation of nontraditional fertilizers for bermudagrass yield Total of two harvests (7/28 & 10/17) 8000 A Bars topped by the same letter are not 7000 different at the 0.05 level AB AB B B B C C C 2000 C Ammomium Ammonium Nitrate Liquid UAN Urea Urea U+Montys Urea + Urea U+S90 + Urea U+FE + Monty's Montys Sea S90 90 Fish FE Untreated Nitrate Urea Monty's Sea 90 Fish Plt Food Mineral Emulsion Check Plt Food Mineral Emulsion Treatments applied on 6/27 and 8/5 Treatment AN, Liq. Urea, & Urea applied at 75 lb/a N Monty's Plt Food pints/a Sea 90 Mineral - 2 lbs/a Fish Emulsion - 4 gal/a Source: John Jennings, University of Arkansas Extension Nontraditional Fertilizer Trial Nitrogen content and total nitrogen applied % N lbs N/unit lbs N applied/acre Treatment Ammonium Nitrate 34% 680 lbs/ton 75 Urea 46% 920 lbs/ton 75 Liquid Urea 23% 2.5 lbs/gal 75 Monty s Plant Food 8% 0.9 lbs/gal 0.2 Fish Emulsion 5% 0.6 lbs/gal 2.4 Sea 90 Mineral 0% 0 lbs/ton 0 Evaluating nontraditional fertilizers Amount nutrient required vs. amount in product Always ask for DATA! Beware of testimonials without data -too much variability in farms, weather, etc. It s OK to experiment, but make sure you have a side-by-side comparison Source: John Jennings, University of Arkansas Extension Ammonium Nitrate vs. Urea Ammonium Nitrate No volatilization Increased yield for forages, corn, and wheat Availability problems b/c of regulatory issues Urea High volatilization rate Need ½ inch of rainfall Coating with Agrotain results in high yields Use when rain chances are questionable Use during high temperatures Tips for Fertilizing on a Budget 1. Take a soil test You cannot manage what you don t measure Helps to determine where to spend your money 7

8 2. Lime First The poor man s fertilizer For cool-season grass: 5.5 to 7.0 For legumes: 6.0 to 7.5 Limit application to 2 to 3 ton/acre/year Applying 2 ton/ac every now and then is NOT a good practice 3. Target Low Testing Soils First Soils that test low to very low will respond to increased fertility faster than soils testing medium or better 100% 95% % Yield 50% Yield Response Curve Apply Buildup + Maintenance Fertilizer Economic Optimum Yield Apply Maintenance Fertilizer Apply No Fertilizer Maximum Yield Detrimental 4. Fertilize at the Right Time Phosphorus, Potassium, and Sulfur can be applied anytime during the growing season These nutrients are stable when in the soil and are less likely to move off site VL L M H VH EX Soil Test Level Fertility Management Potassium may need to be applied in split applications because of luxury consumption Bermudagrass Alfalfa Fertility Management Nitrogen should be applied when the plant has the ability to respond This nutrient is mobile and has the ability to move away from the plants root zone 8

9 Nitrogen for Tall Fescue Hay Spring fertilization for Hay: - apply nitrogen in mid March - maximizes natural growth curve Nitrogen for Tall Fescue Pasture Spring fertilization for Pasture: - apply nitrogen in early May - extends spring forage into July - less response, higher potential value Forage Yield Herd feed requirement Forage Yield Herd feed requirement April June August October April June August October Nitrogen for Tall Fescue Pasture Fall fertilization for Pasture: - apply nitrogen in mid August - increases and extends fall forage - less response, higher potential value 5. Add Legumes Legumes can add lb N/year Need 30% in the stand to have a significant impact Forage Yield Herd forage demand April June August October Nodulated Plants Produce Nitrogen Seeds should be inoculated to ensure fixation Not inoculated Inoculated

10 Yield of Tall Fescue & Clover vs. Tall Fescue & Nitrogen Treatment Yield lb/acre Tall fescue + red clover 11,100 Tall fescue + N 0 lb N/acre 3, lb N/acre 6, lb N/acre 9, Source: Taylor Kentucky Agric. Ext. Ser. AGR-26 % Lespedeza Nitrogen Fertilization of Grass/Legume Mixes Lbs/acre N 6. Manage Other Resources Treatment 1 Treatment 2 Treatment 3 Consider how & where you feed hay... Unrolling, stationary bale rings, move bale rings Dragging Hay Ring in Set Feeding Area 40 X 40 Move Hay Ring Every Other Day 20 X 40 Unroll Hay in a New Spot Daily Stationary Ring Move Hay Feeding Sites Often Moving Ring Regularly move feeders and feeding areas Do not use the same pasture for supplemental feeding every year Unrolling Hay 10

11 Unrolling Hay Allows boss cows and timid cows to eat together Less hoof damage to feeding area because it is larger Distributes fertilizer nutrients back on field 62 Manures The good: Adds organic matter Helps improve many aspects of soil health Adds micronutrients Current price = $24 to $35/ton dumped The bad: The smell Transportation costs Availability Nutrient variability Nutrient Concentration of Manures Source Units N P 2 O 5 K 2 O Poultry Litter lbs/ton Beef Feedlot lbs/ton Dairy Slurry lbs/1000 gal Pig Slurry lbs/1000 gal Pig Effluent lbs/acre-in Research adapted from Dr. John Lory, University of Missouri N, P, and K in Poultry Litter Fertilizer Value 20 to 60% of N can be lost when surface applied Plants take up phosphate (P 2 O 5 ), not phosphorus (P) - 80% Available Yr. 1 (100% by Yr.2) P X 2.27 = P 2 O 5 Plants take up potash (K 2 O), not potassium (K) - 100% Available Yr. 1 K X 1.2 = K 2 O Formula: lbs/ton X availability X price/lb = fertilizer value Nitrogen 55 X 0.6 X 0.71 = $23.43/ton Phosphate (DAP) 78 X 1.0 X 0.54 = $42.12/ton Potash 55 X 1.0 X 0.55 = $30.25/ton Total value = $95.80/ton 11

12 Fertilizing on a Budget 1. Conduct a soil test 2. Lime first 3. Target very low and low testing soils 4. Fertilize at the right time 5. Add legumes 6. Manage manure resources Consequences of Foregoing Fertilizer Reduced forage production Reduced persistence of desirable species Excessive weeds and brush Reduced forage quality Yield loss Questions? 12