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Nutrient Testing
& Recordkeeping

NOTE: Producers are responsible for taking all samples and for maintaining records for at least 5 years. Following these guidelines will help you follow your farm plan and also fulfill regulatory requirements. Operations under CAFO Permit may need additional sampling. 

THE NUTRIENT SAMPLING CALENDAR:

APRIL - MAY

Take MANURE SAMPLES (solid and liquid) when you are applying the majority of your manure - this is Spring for most producers. Agitating your manure will help with consistent sample results.

JUNE - JULY​

Dial in your application with a Pre-Sidedress Nitrate Test. This is an optional test for corn fields to determine if and how much to sidedress. Sample at the 5-leaf stage or when plants are 12" tall.

SEPT - OCT

Take SOIL SAMPLES in the fall, after harvest and before 5" of rain have accumulated. These samples will tell you if you over or under applied and will help you plan for next year's application.

 
 

SUMMARY OF REQUIRED NUTRIENT TESTING:

SOIL TESTING TIPS:
  • SAMPLE EVERY YEAR in September or October test for Nitrate Nitrogen (NO3-N)

  • SAMPLE EVERY THREE YEARS in September or October do a comprehensive soil test including:
    • Nitrate Nitrogen (NO3-N), Ammonium Nitrogen (NH4-N), Bray Phosphorus (P-Bray), Potassium (K), pH, Electrical Conductivity (EC), and Organic Matter (OM),

  • CONSIDER A PRE-SIDEDRESS NITRATE TEST (PSNT) This test is optional and can be performed on corn ground prior to fertilizer sidedress. Sample at the 5-leaf stage or 12" plant height and use the results to determine your application rate.

  • USE PROPER SAMLING TECHNIQUE: Sample your soil at a depth of 12" and gather soil from multiple points across your field. Most labs require 1-2 cups of soil per sample. Fields managed the same can be combined. Click Here for more information on soil sampling.

  • UPDATE YOUR MAPS: Make sure your maps are updated and field numbers match your sampling records. A sample is only helpful if you know where it was taken! Whacom Conservation District offers free mapping services. 

  • USE AN ACCREDITED LAB: Click here for a comprehensive list

  • UTILIZE YOUR SOIL TESTS: These tests are meant to be used when planning your application rates. Recordkeeping is only helpful you take the time to consider those records and adjust your management for the improved efficiency of your operation. 

MANURE TESTING
  • Licensed dairies are required to take at least one sample each year for the following manure types:

    • Solid Manure​

    • Liquid Manure

    • Any composted materials applied to fields (mortalities, etc.)

  • Test manure samples for the following:

    • Total Nitrogen (TN)​

    • Ammonium Nitrogen (NH4-N)

    • Phosphorus (P)

    • You may also choose to test for Percent Moisture, Potassium (K), Calcium (Ca), Sulphur (S), and Magnesium (Mg)

  • Time manure sampling with your application so that you know what your fields are receiving.

  • Collect samples during or after agitating so that the material is thoroughly mixed. Best practice is to pull multiple samples from different parts of the lagoon or drystack and combine them into a composite sample for submission. 

  • Send your samples to an accredited laboratory. Most labs require a 250mL sample size. You can mail samples to any accredited lab or there are currently two accredited labs in Whatcom County:

  • This sample information is very valuable for you to use in planning your manure applications. Don't just let them sit on a shelf - use them! For assistance on how to utilize your manure testing records contact WhatcomCD

OTHER RECORDKEEPING REQUIREMENTS
  • APPLICATION RECORDS: Make sure to track the following information for each application:

    • Date, Field Number (make sure it matches your map), Crop, Expected Yield, Manure Type, Amount Applied, Application Method, and Weather Conditions​

    • Use this Tracking Form to share with your application staff or this Tracking Spreadsheet to use yourself. Whatcom CD can also provide you with a handy notebook to keep in your tractor or truck. Email us to request one!

    • Use the ARM Worksheet to track weather and gauge your application risk. Print each worksheet for your records to document that you did your due diligence to avoid runoff. 

  • IRRIGATION RECORDS

    • Track the total inches of irrigation each field receives annually 

  • HARVEST RECORDS

    • Track date of harvest, crop, and amount harvested (tons/acre)​

  • IMPORT/EXPORT RECORDS

    • Track the following information​:

      • Date of transfer​

      • Type of manure (solid, liquid, separated solids, compost, etc.)

      • Amount transferred (gallons or tons)

      • Name and location of person supplying or receiving the manure

    • Use this Transfer Agreement to document the exchange

Forage testing and determination of crop yield are highly recommended but not required. A minimum test should include: percent moisture, and crude protein for each harvest. Testing for fiber (ADF, NDF, CF and Lignin) and minerals, especially potassium, is also recommended.  

The Washington State Department of Agriculture (WSDA) released the latest Nutrient Management Recordkeeping Requirements (WAC 16-611) effective November 2012. Be sure you are following the requirements laid forth. Contact your planner if you have any questions.