The wording in the source

Timing

• Beginning in the year following the initial soil sampling required by this section, the permittee shall collect annual soil samples from each field within the land application area that has received or is actively receiving wastewater or stormwater.

  20.6.6.25.L NMAC

• For those fields that have never before received wastewater, the permittee shall collect soil samples immediately before initial wastewater application and annually thereafter.

  20.6.6.25.L NMAC

• Once a field has received wastewater it shall be sampled annually regardless of whether the field is cropped, remains fallow, or has recently received wastewater or stormwater.

  20.6.6.25.L NMAC

• A permittee shall collect composite soil samples from each field within the land application area for the first soil sampling event during the first year following the effective date of the discharge permit.

  20.6.6.25.K NMAC

Method

• Each surface and sub-surface soil sample shall consist of a single composite of 15 soil cores collected randomly throughout each field. Should a field consist of different soil textures (i.e., sandy and silty clay), a composite soil sample shall be collected from each soil texture within each field.

  20.6.6.25.L(1) NMAC

Depth

• One surface composite soil sample (first-foot) and two sub-surface composite soil samples (second-foot and third-foot) shall be collected from each field.

  20.6.6.25.L NMAC

• Surface soil samples (first-foot) shall be collected from a depth of 0 to 12 inches.

  20.6.6.25.L(2) NMAC

• Each second-foot sub-surface soil sample shall be collected from a depth of 12 to 24 inches.

  20.6.6.25.L(3) NMAC

• Each third-foot sub-surface soil sample shall be collected from a depth of 24 to 36 inches.

  20.6.6.25.L(4) NMAC

Cores

• Each surface and sub-surface soil sample shall consist of a single composite of 15 soil cores collected randomly throughout each field.

  20.6.6.25.L(1) NMAC

Who it applies to

• ADDITIONAL MONITORING REQUIREMENTS FOR DAIRY FACILITIES WITH A LAND APPLICATION AREA:

  20.6.6.25 NMAC, heading

• Beginning in the year following the initial soil sampling required by this section, the permittee shall collect annual soil samples from each field within the land application area that has received or is actively receiving wastewater or stormwater.

  20.6.6.25.L NMAC

Laboratory and analysis

• pH, electrical conductivity, sodium, calcium, and magnesium shall be analyzed using a saturated paste extract in accordance with the analytical methodology required by Subsection B of 20.6.6.24 NMAC. Phosphorus shall be analyzed using the Olsen sodium bicarbonate method

  20.6.6.25.L(7) NMAC

• Nitrate as nitrogen shall be analyzed by a 2 molar KCl extract

  20.6.6.25.L(7) NMAC

Field identifiers

• The permittee shall submit the analytical results and a map showing the fields and the sampling locations within each field to the department in the monitoring report due by May 1.

  20.6.6.25.L(8) NMAC

In force

• EFFECTIVE DATE: 01/31/2011, unless a later date is cited at the end of a section.

  20.6.6.5 NMAC

• [20.6.6.25 NMAC – N, 01/31/2011; A, 12/31/2011; A, 06/16/2015]

  20.6.6.25 NMAC, history note

The wording in the source

Timing

• It is recommended to test your soil every year before the crop season to assess its chemical and nutrient status. If that is not possible, then at least every other year.

  Guide A-146, Introduction

Area per sample

• Crop fields larger than 25 acres should be divided into separate sampling sections to capture differences within the field.

  Guide A-146, Collecting a Sample from the Field

Method

• Samples should be taken from areas that can be treated as distinct units (management zones).

  Guide A-146, Collecting a Sample from the Field

• When deciding how to divide a field, consider historical yield variation along with factors like slope, weed pressure, and soil type.

  Guide A-146, Collecting a Sample from the Field

• The recommended number of subsamples ensures that the sample is representative of a “management zone.” This area may be treated the same for watering, fertilizer application, and yield potential.

  Guide A-146, Collecting a Sample from the Field

Depth

• Areas that are not tilled, such as direct-seeded fields, orchards, vineyards, turfgrass, and perennial gardens, should be sampled to a depth of 6 to 8 inches. Any area that has been tilled, such as annual gardens, conventionally tilled production fields, or similar areas, should be sampled to a depth of 12 inches.

  Guide A-146, Collecting a Sample from the Field

Cores

• It usually takes 10 to 15 subsamples taken to the same depth and combined into one sample in order to be confident in the soil test results from any given lab.

  Guide A-146, Collecting a Sample from the Field

Laboratory and analysis

• Consider using laboratories that participate in the North American Proficiency Testing Program (Table 1).

  Guide A-146, Laboratories

• For New Mexico soils, pH should be determined on the saturated paste (pHs), which best reflects field conditions.

  Guide A-146, What Analyses to Request, pH