N Broadcast

When N is Broadcast (SPRING)

 

Tracking Sample Collection

Purpose: To provide a management tool that tracks the dynamics of plant-available N over time. It provides away to inventory, track, and verify the concentration of nitrate and ammonium-N at a point in the field from post-harvest to post-harvest the following crop year. It is a management tool that provides a point-in-time snapshot of plant-available N remaining in the soil from left-over N following harvest to any excess or lack of plant-available N during the early part of the crop’s growing season. It is a strategic tool to use when managing N as a system to Minimize environmental impact by Optimizing harvest yield and Maximizing N utilization. (focus on M.O.M.)

 

  1. Determine the best location of the N-WATCH site. Consider how it represents other areas within the field and ease of sample collection. Record the latitude and longitude (prefer decimal format) for use when registering the site. Note: Select site to make it most convenient for sampling access.
  2. Register the site at www.nwatchonline.com.
  3. Farmer participants must electronically sign the Information Management Disclosure Statements (Agree/Disagree)
  4. Identify a 20 ft. x 20 ft. site after harvest of corn where samples will be collected. Collect 4 random cores from the designated area at a depth of 0-1 foot and place the cores in a labeled sample bag. Mark the sampling site with a flag or stake. It is important to pull future cores in close proximity to the previous cores collected to minimize variation due to position.  Visit www.nwatchonline.com for more information about soil probe options.
  5. Collect a 1–2 foot sample as described above using the same holes.  Collect the 1-2 foot soil sample from the same hole.  Mark the probe with a permanent marker or a metal file when the first 1-2 foot core is removed.  This can serve as a guide for the remaining core depths. 
  6. Note: Some surface soil may fall into the holes prior to pulling the 1-2 foot samples. Observe the core as it is extracted from the soil. If you note loose, dry soil sitting on top of the 1-2 foot core, remove it with your fingers prior to placing the sample in the mixing bucket. Use good judgement. The template will help keep the soil from falling back into the hole once the first set of cores is removed.

Tracking plant-available N over time:  Mark the sample sites with a flag to easily identify the location. You will need to collect the next sample in the same way from the same location, moving a few inches away from the previous hole. Pull a set of samples (0-1 ft. and 1-2 ft.) at the times provided in Table 1.

 

Table 1.  Suggested times to collect N-WATCH samples.

1 - Spring Thaw 3 - Early corn grown (V3-V4)
2 - Pre-plant or after Spring N 4 - Post Harvest (Pre if cover crop considered)
Note: Only Spring sampling dates listed. There are an additional 2 sampling dates suggested for fall collection.

 

Pull samples from the same area in the same way. No reason to sample soils when dry and hard. If it is difficult to get the probe in the soil wait until conditions are conducive for easier sample collection. Soil N will not be lost by denitrification or leaching if the soil is hard and dry.

Submit all samples with the provided shipping materials within 24 hours of collection along with a completed submittal form. Refrigerate over weekend if pulled on a Friday and ship on Monday. Do not ship samples to the lab unless they will arrive and be processed prior to the weekend. Provide ALL the information requested on the submittal form. An incomplete form will delay generation of the N-WATCH report.


 

N Banded-Tracking

When N is Injected, Knifed, or banded (SPRING)

 

Tracking Sample Collection

Image 1. Collect soil samples (2 cores) 0-1 ft. at each of eleven sets of holes in the template (3 inches apart). Collect samples at 1-2 ft. using the same holes and following the same sample collection procedure. There will be 22 samples once both sampling depths are collected.

Purpose: To provide a management tool that tracks the dynamics of plant-available N over time. It provides a way to inventory, track, and verify the concentration of nitrate and ammonium-N at a point in the field from post-harvest to post-harvest the following crop year. It is a management tool that provides point-in-time snapshots of plant-available N remaining in the soil from left-over N following harvest to any excess or lack of plant-available N during the early part of the crop’s growing season. It is a strategic tool to use when managing N as a system to Minimize environmental impact by Optimizing harvest yield and Maximizing N utilization. (focus on M.O.M.)

 

  1. Determine the best location of the N-WATCH site. Consider how it represents other areas within the field and ease of sample collection. Record the latitude and longitude (prefer decimal format) for use when registering the site. Record the location’s coordinates to 6 digits right of the decimal point.
  2. Register the site at www.nwatchonline.com.
  3. Farmer participants must electronically sign the Information Management Disclosure Statements (Agree/Disagree)
  4. Use a template (Image 1) to pull 11 soil cores that are spaced 3 inches apart at a 0-1 foot depth (one side of template). Mix the 11 cores thoroughly in a bucket and place a subsample in an appropriately labeled sample bag. Make sure the template is placed perpendicular to the direction of injected/banded N applications. Collect a 2nd sample at 1 to 2 feet using the same holes and procedure. Mark the sampling site with a flag to identify the location. Plan to collect the next samples at the same location by moving the template a few inches. Visit www.nwatchonline.com for more information about soil probe options.
  5. Note: Some surface soil may fall into the holes prior to pulling the 1-2 foot samples. Observe the core as it is extracted from the soil. If you note loose, dry soil sitting on top of the 1-2 foot core, remove it with your fingers prior to placing the sample in the mixing bucket. Use good judgement. The template will help keep the soil from falling back into the hole once the first set of cores is removed.

Tracking plant-available N over time: Mark the sample sites with a flag to easily identify the location.  You will need to collect the next sample in the same way from the same location, moving a few inches away from the previous hole.  Pull a set of samples (0-1 ft. and 1-2 ft.) at the times provided in Table 1.

 

Table 1.  Suggested times to collect N-WATCH samples.

1 - Spring Thaw 3 - Early corn grown (V3-V4)
2 - Pre-plant or after Spring N 4 - Post Harvest (Pre if cover crop considered)
Note: Only Spring sampling dates listed. There are an additional 2 sampling dates suggested for fall collection.

 

Pull samples from the same area in the same way. No reason to sample soils when dry and hard. If it is difficult to get the probe in the soil wait until conditions are conducive for easier sample collection. Soil N will not be lost by denitrification or leaching if the soil is hard and dry.

Submit all samples with the provided shipping materials within 24 hours of collection along with a completed submittal form. Refrigerate over weekend if pulled on a Friday and ship on Monday. Do not ship samples to the lab unless they will arrive and be processed prior to the weekend. Provide ALL the information requested on the submittal form. An incomplete form will delay generation of the N-WATCH report.


 

N Banded-Inventory

When N is Injected, Knifed, or banded

 

One-Time Sampling

Image 1. Collect soil samples (2 cores) 0-1 ft. at each of eleven sets of holes in the template (3 inches apart). Collect samples at 1-2 ft. using the same holes and following the same sample collection procedure. There will be 22 samples once both sampling depths are collected.

Purpose: To provide a management tool that tracks the dynamics of plant-available N over time. It provides a way to inventory, track, and verify the concentration of nitrate and ammonium-N at a point in the field from post-harvest to pollination-time the following crop year. It is a management tool that provides point-in-time snapshots of plant-available N remaining in the soil from left-over N following harvest to any excess or lack of plant-available N during the early part of the crop’s growing season. It is a strategic tool to use when managing N as a system to Minimize environmental impact by Optimizing harvest yield and Maximizing N utilization. (focus on M.O.M.)

 

  1. Determine the best location of the N-WATCH site. Consider how it represents other areas within the field and ease of sample collection. Record the latitude and longitude (prefer decimal format) for use when registering the site. Record the location’s coordinates to 6 digits right of the decimal point.
  2. Register the site at www.nwatchonline.com.
  3. Farmer participants must electronically sign the Information Management Disclosure Statements (Agree/Disagree)
  4. Use a template (Image 1) to pull 11 soil samples that are spaced 3 inches apart at a 0-1 ft. depth. Collect two cores at each spacing (to have enough soil for analysis). Make sure the template is placed perpendicular to the direction of injected/banded N applications. Label each bag to identify where the sample was pulled in relationship to other samples (0, 3, 6, 9, 12, 15, 18, 21, 24, 27 and 30 inches). Collect a 2nd sample at 1 to 2 feet using the same holes and labeling the sample bags appropriately. Mark the sampling site with a flag to identify the location. Plan to collect the next samples (Tracking) at the same location by placing the template a few inches away. Visit www.nwatchonline.com for more information about soil probe options.
  5. Note: Some surface soil may fall into the holes prior to pulling the 1-2 foot samples. Observe the core as it is extracted from the soil. If you note loose, dry soil sitting on top of the 1-2 foot core, remove it with your fingers prior to placing the sample in the mixing bucket. Use good judgement. The template will help keep the soil from falling back into the hole once the first set of cores is removed.

 

Pull samples from the same area in the same way. No reason to sample soils when dry and hard. If it is difficult to get the probe in the soil wait until conditions are conducive for easier sample collection. Soil N will not be lost by denitrification or leaching if the soil is hard and dry.

Submit all samples with the provided shipping materials within 24 hours of collection along with a completed submittal form. Refrigerate over weekend if pulled on a Friday and ship on Monday. Do not ship samples to the lab unless they will arrive and be processed prior to the weekend. Provide ALL the information requested on the submittal form. An incomplete form will delay generation of the N-WATCH report.