Agronomic and Economic Considerations on Michigan Fertilizer...MSU Phosphorus and Potassium...

Click here to load reader

  • date post

    18-Apr-2018
  • Category

    Documents

  • view

    217
  • download

    3

Embed Size (px)

Transcript of Agronomic and Economic Considerations on Michigan Fertilizer...MSU Phosphorus and Potassium...

  • Agronomic and Economic Considerations on Michigan Farms

  • MSU Phosphorus and Potassium

    Fertilizer Recommendations for Field Crops

    The key ingredients: Soil Test Information Yield Goal Buildup, Maintenance and drawdown

  • Soil sampling

    Sample should represent the field

    Sampling pattern for three separate uniform fields

    Each sample should be composed of at least 20 cores

  • Loam Formerly 2 fields

    now all 1 field

    Sand

    Muck

    Never limed

    Limed 5 years ago

    3 zones 2 zones 2 zones

    15 T/a manure

    last year

    No manure Flat

    Poorly drained

    2 zones 3 zones

    Zone delineation (non-uniform)

  • MSU Phosphorus and Potassium

    Fertilizer Recommendations for Field Crops

    The key ingredients: Soil Test Information Yield Goal Buildup, Maintenance and drawdown

  • Building up low soil testing soils to a critical level Adding P and K to maintain that level year after year Flexibility to change the rate

    Buildup and Maintenance Approach

  • Buildup and Maintenance Approach

    0 15 30 45 ppm Critical level - Soil test level to achieve economic optimum (95-97% of the maximum yield)

  • Critical Soil Test P Value The soil test level where you achieve economic optimum yield (95-97% of the maximum yield)

  • Critical Soil Test P Level

    Crop

    Critical P level (ppm)

    Corn 15

    Soybean 15

    Wheat 25

    Alfalfa 25

    The soil test level where you achieve economic optimum yield (95-97% of the maximum yield)

  • Buildup and Maintenance Approach

    Buildup and Maintenance Approach

    0 15 30 45 ppm Critical level - Soil test level to achieve economic optimum (95-97% of the maximum yield)

  • Buildup and Maintenance Approach

    MSU recommended P fertilizer practices

    Soil Test Level Recommended Fertilizer Rate

    Buildup range (< Critical level) Apply rates to buildup to critical level plus crop removal rate

    Maintenance range (>critical level) Only apply crop removal rate

    Drawdown range (> maintenance limit) only starter P or No Phosphorus

  • Crop Yield lb P2O5/A removed

    lb K2O/A removed

    Corn 180 Bu 67 48

    Soybean 45 Bu 36 63

    Wheat 75 Bu 47 28

    Alfalfa 4 Tons 52 200

    Phosphorus and Potassium Removal Rates (based on the yield goal in soil test)

  • MSU Soil Test Lab Report

    The bar chart closely corresponds to the buildup (below

    optimum), maintenance (optimum) and drawdown ranges

    (above optimum).

  • Soil Test Lab Report

    The bar chart closely

    corresponds to the

    Below optimum

    (Buildup )

    Optimum

    (Maintenance)

    Above Optimum

    (Drawdown)

    Analysis

    Recommendation

    *

  • Buildup and Maintenance Approach

    Critical Soil Test K Level

    Crop

    Critical K level (ppm) CEC = 10 me/100g

    Corn 100

    Soybean 100

    Wheat 100

    Alfalfa 100

    Potassium is positively charged and attracted to clay or

    organic matter (Limited losses to environment)

  • P in soil Many years to build-up and drawdown

    Applying manure to meet all the N needs of corn

    leads to over application of P

    Maintain soil pH range at 6.0-6.8 (Use lime if

    necessary good return to investment)

    P and K can be applied in the fall or spring

    (Fall K fertilizer applications on sandy soils with low

    organic matter are discouraged)

    P and K Management Considerations

  • More information on this approach Special situations

    will be discussed at the advanced session

  • Macronutrients Nitrogen (N), Phosphorus(P), and Potassium(K) Required in large amounts and likely to be deficient

    Secondary Nutrients Calcium (Ca), Magnesium(Mg) and Sulfur(S)

    Required in large amounts but less likely to be deficient

    Micronutrients Manganese (Mn), Zinc (Zn), Boron (B), Copper (Cu), Iron (Fe), and Molybdenum (Mo) Required in trace amounts

    18 Essential Plant Nutrients

    Carbon (C), Oxygen (O), and Hydrogen(H) are derived from atmospheric carbon dioxide and soil water

  • A sketch map indicating each soil unit/management zone

  • Physical make-up of the soil

    Accurately determine available nutrients.

    Evaluate the probability of deficiencies, excesses or imbalances.

    Serve as a basis for making fertilizer recommendations.

    Determine the soil pH.

    What does a soil tests show

  • Sampling a Field

    2. Grid

  • A sketch map indicating each soil unit/management zone to be sampled will be helpful.

    Here are some examples:

  • Whole Field Sampling pattern for three separate uniform fields

    Each sample should be composed of at least 20 cores

  • Grid Systematic sampling

    Used where nutrients will be applied variably

    Can be useful if purchase/rent new ground and past history not well known

    Plus good assessment of nutrient variability

    Minus expensive

  • Grid

    Sample locations have GPS coordinates

    Sample consists of at least 10 cores composited within a 10 radius of grid point

  • Buildup and Maintenance Approach

    apply only the maintenance rate (crop removal) and

    not buildup

    In the drawdown range, skip any P and K application

    Short term strategy or on rented land

  • Buildup and Maintenance Approach

    Short term strategy or on rented land

    Apply P and K first to fields most in need (below critical level) and then allocate the remaining fertilizer to fields with adequate levels

    Only band application 25 - 40 lb/A P and K

    On fields that have the same soil test levels, applying fertilizer at 70% of the recommended rate on all acreage will provide a higher economic return than applying the full rate on 70% of field acres and none on 30% of the acres.

  • Field Recommended Rate lb/A

    Application rate lb/A

    (option 1)

    Application rate lb/A

    (option 2)

    1 100 70 100

    2 100 70 100

    3 100 70 10

    Situation Low testing soil but need to cut down fertilizer. Recommendation 300 lb. Only have 210 lb. (30% reduction)

  • Fertilizer Grade A bag of 10-10-10 fertilizer contains 10 % nitrogen, 10 % phosphate and 10 % potash A bag of 46-0-0 fertilizer contains 46 % nitrogen, 0 % phosphate and 0 % potash A bag of 0-0-60 fertilizer contains 0 % nitrogen, 0 % phosphate and 60 % potash

    If the soil test recommendation is for 120 lb/A potassium, then use a 200 lb of potash (0-0-60).

  • N-P-K Fertilizers

    Common Fertilizer Grade Nutrient Cost

    $/ton fertilizer*

    Urea 46-0-0 N 564

    Anhydrous Ammonia 82-0-0 N 785

    UAN 28% N 385

    Triple Super Phosphate

    0-46-0 P205 614

    Muriate of Potash 0-0-60 K20 630

    Diammonium Phosphate (DAP

    18-46-0 N and P 634

    Monoammonium Phosphate (MAP)

    11-48-0 N and P 704

    Ammonium Polyphosphate

    10-34-0 N and P 849

    Bulk 19-19-19 N, P and K 615

    Bulk 6-24-24 N, P and K 627

    Bulk 16-35-5 + Zn + S N, P, K, Zn, S 726