Pasture Biomass Collector

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Introduction

Cibo Labs have developed and deployed two PUBLIC survey forms for collecting pasture biomass information. These forms are:

  • Pasture Biomass Image Library - for initial data collection by users to create a one-pager of reference images (low, mod and high biomass) for different types of pasture.

  • Pasture Biomass Collector - form for quadrat data collection along transects

These survey forms are mobile data collection apps for undertaking rapid pasture assessments in the paddock, they have been designed to stream line data collection in the field.

This collected data can be used as information for direct input to forage budgets, or for calibration of satellite imagery. The surveys allow the user to undertake visual quadrat assessments along transects; take photos and record information on pasture types and condition. The surveys work offline with both Android and IOS devices using the ESRI Survey123 mobile application (https://esriaustralia.com.au/survey123-for-arcgis).

 

The two survey forms are designed to be used together, using first:

Pasture Biomass Library - Public

  • This is a “crowd-sourcing” form available for anyone to use. All records are stored in our online database as line features (transects) and points (quadrats)

  • The user provides their email address for each transect collected uploaded, this email is used to send a one-page report as a image reference file.

  • The user only receives reports with each transect uploaded, to have the reference file ready for the next phase with collecting data with the ‘Pasture Biomass Collector’.

 

Pasture Biomass Collector - Public

  • This is also a “crowd-sourcing” form available for anyone to use. All records are stored in our online database as line features (transects) and points (quadrats)

  • The user provides their email address for each transect collected and uploaded, this email is used to send a “live link” to all collected data as a Google Sheet, which streams the data and image links back to the user when mobile data services are available.

 

These surveys are provided for free as an industry service with the expectation that the user, Cibo Labs and the broader industry will receive mutual benefits from the data collected.

 

Installing the Survey123 app and Accessing the Public Survey forms

 

The user grants Cibo Labs a non-exclusive, perpetual, royalty free licence to use and adapt the data for internal commercial and non-commercial purposes: namely the ability to use the data for development of satellite model calibrations and related purposes.

The Cibo Labs Privacy Policy and Terms and Conditions are located here:

Collecting and Submitting Records

Before you begin collecting records for a transect, make sure you are standing at the start of the transect.

Once you have completed collecting records and information for a transect click the ‘TICK’ at the bottom right of the survey form. When you click the 'TICK' you will be presented with options:

  • Send now - only do this if you have a strong mobile service of WiFi

  • Send later - when you don’t have an internet connection

  • Continue this survey - return back to the current survey

  • Save to Outbox - so you can update or add new data before sending.

Start

Click the ‘Collect’ button:

Click the ‘Send now’ to have the records sent or 'Save in Outbox' if you want to edit again later.

Create Your Favorites

You can use 'Favorite answers' to save commonly used text entry for these forms, once you have entered your email and your most common Property Name or Paddock Name.

Click the menu (three lines) and click add as Favorites

Click ‘Paste answers from favorite’

You can remove your favorites, use the 'Clear as favorite answers'

If the favorites don't work, then you could copy your email address prior to using the survey forms and paste it into the email text box.

Accessing data collected on the App

Once the data has been sent or saved for editing later, you can edit these created or sent transect records by clicking on the other menu items ‘Sent’ or ‘Outbox’. This will display all survey records ever sent by this device.

All your previous transect records are accessible from the Survey123 form details page.

Click on the three dots to edit or delete or even copy records into a new survey.

Click on the three dots to edit or delete or even copy records into a new survey.

 

Visual Pasture Referencing with the Pasture Biomass Library

Getting yourself “calibrated” for visually estimating pasture biomass

The App has been developed specifically for estimation of pasture biomass based on visual quadrat estimates along a transect with known GPS coordinates. We must assume that users have undertaken practice in pasture biomass estimation, however, some tips are also included here.

There are numerous resources available to assist with making visual estimates of pasture biomass (https://www.feedonofferlibrary.com/, https://futurebeef.com.au/knowledge-centre/pasture-photo-standards/. However, we highly recommend that in order to get “your eye in”, prior to field sampling, you undertake your own cuts; complete some oven drying to estimate pasture dry matter (DM), and take some photos to create your own reference library over time.

You will need the following: 0.25sqm quadrat for most northern pastures and a 0.1sqm quadrat for most southern improved pastures; plastic bags for doing “wet weights”; paper bag for oven drying sub-samples of pasture; electric clippers or hand shears.

  1. Start with ‘Collect’, then enter your email address, property, paddock

  2. For a given pasture type, select a low, medium and high biomass location.

  3. Place the quadrat on the pasture and take a vertical reference photo

  4. Cut and bag the pasture as close to ground level as possible.

  5. Weigh the samples in the paddock as soon as possible after you have cut them to avoid them drying out. Don’t forget to “zero” the scales with the bag to remover the bag weight.

  • Weigh and record the quadrat samples.

  • 0.25sqm quadrat - grams x 40 = kg/ha

  • 0.1sqm quadrat - grams x 100 = kg/ha

  • Remember these are “wet weights” and must be adjusted for the moisture content to derive dry matter (DM%)

Start with the Pasture Biomass Library form - https://arcg.is/0HiXCb

Enter you email, Property Name, Paddock Name and the pasture species being represented.

Choose ‘Other’ if species not in list

Select the Low, Mod, or High as a representation of the pasture biomass sample being taken.

Enter wet weights and take photos and leave the rest for editing later after the drying process.

MOVE TO THE NEXT QUADRAT LOCATION

Then create the new quadrat point by clicking the '+'.

 

 

 

  1. Dry matter samples (DM%) - Take a representative sample of pasture next to the quadrat and place in a paper bag for oven drying. A handful is enough.

  2. Weigh the dry matter samples as soon as possible and record the weight on the bag. Place in an oven at 80degC for minimum of 12 hours. Weigh again and place back in the oven for another 2hrs and weigh again. You can also use a microwave (see ‘Silage Note No. 7’).

  3. If the weight hasn’t changed it is ready to calculate DM content

  • DM% = dry weight / wet weight

  • Hay would normally have a DM% of ~85%

  • Actively growing cereal crops are likely to be ~30-40% DM%

  • Partially cured perennial pastures might be 50-70% DM%.

  • The message here is that DM% varies substantially and has a huge effect on estimates.

Calculate the DM yield (kgDM/ha) by multiplying your Wet Weights by DM%.

  • E.g Wet Weight = 1500kg/ha x 0.7 (DM%) = 1050 kgDM/ha.

For most properties you should be able to collate enough cuts and photos across your major pasture types and biomass levels in a morning. Complete the oven drying overnight, compile your photos against the DM weights into a document, and you have your own library to refer to, and to provide staff with a local reference.

Doing Visual field estimates using the Pasture Biomass Collector

Once you are confident in your ability to make visual estimates based on using existing photo standards, or creating your own library, you are ready to use the Biomass Collector App.

  1. Open the App from your home screen, and enter your email address, property, paddock

  2. Ensure that you are at least 100m away from roads, or abrupt changes in biomass.

  3. Locate the start of the transect and place your quadrat on the ground with the bottom left corner next to your toe.

Start with the Pasture Biomass Collector form - https://arcg.is/0TW5iS

  1. Enter your email address, Property Name and Paddock name

  2. Take a site photo across the intended transect. Select a point that you intend walking to in a straight line

 

  1. Enter your first Quadrat TSDM (kg/ha) estimate.

  2. Take a vertical photo at elbow height directly down onto the quadrat (try to avoid shadows)

  3. And estimate pasture height in cm.

  1. Enter the Pasture Species (choose ‘Other’ if species not available in list)

  1. Record the estimates of dominant pasture species, unpalatable species %; unpalatable 3P %; DM%; Green Fraction %, and any comments.

  2. Then click the ‘TICK’ at the bottom right of the form.

 

 

Doing Pasture Cuts for Wet Weights

Collecting Pasture Cuts – to create calibration equations.

  • The objective is to collect pasture cuts across the range of biomass levels for a given pasture type that you have just collected EC20 transects across.

  • You should be able to do this within walking distance of your vehicle so you don’t have to carry your gear too far.

  • Create a [Paddock/Site] in the EC20 App called <Cal><time>. e.g. Cal1145.

  • Knowing the range of heights you have just traversed – select a number of low, medium and high locations – usually within a few paces.

  • Drop the EC20 on the selected locations to get a height reading – then place the Quadrat down on that location. Make sure you have sampled down to at least 50mm and up to the tallest plants. Please ignore rank pastures.

  • Label the bags with the time, pasture type and EC20 height.

  • Dry Matter % cuts see section 6 below.

  • Repeat until you think you’ve sampled across the range of height/biomass levels – Generally 9-12 quadrat cuts should be enough for the initial calibrations for a pasture type. We need several cuts for each of your low, medium and high categories.

  • Weigh the WET Quadrat cuts as soon possible within a couple of hours of collection and keep them out of the sun. Don’t forget to zero the scale with the bag. Record the following into a simple spreadsheet. You can throw these cuts away. Don’t throw the DM% samples away just yet:

 

  1. Dry matter samples (DM%) - Take a representative sample of pasture next to each quadrat and place in a paper bag for oven drying. 1-2 handfuls are enough.

  2. Write the date, time, species on the bag for later weighing.

  3. Weigh the dry matter samples as soon as possible and record the weight on the bag (within 2hrs). Keep them out of the sun, and do not put the paper bags in another plastic bag where they might create condensation.

  4. Place in an oven at 80degC for minimum of 12 hours. Weigh again and place back in the oven for another 2hrs and weigh again.

  5. If the weight hasn’t changed it is ready to calculate DM content

  6. DM% = dry weight / wet weight

  • You can also use a microwave (see ‘Silage Note No. 7’) but an oven is faster for a large number of samples.

  • Hay would normally have a DM% of ~85%

  • Actively growing cereal crops are likely to be ~30-40% DM%

  • Partially cured perennial pastures might be 50-70% DM%.

The message here is that DM% varies substantially and has a huge effect on estimates.

Select Wet Weight Sample with the form.

Enter the wet-weight measurements in field

 

 

Using an EC20 Plate Meter with Pasture Biomass Collector

 

The EC20 Plate meter provides a rapid means of collecting reliable estimates of compressed pasture height that can be related to pasture biomass at specific locations which we then use for calibrating remotely sensed imagery. However, different pasture types and growth stages will have different relationships that need to be quantified before reliable field estimates of biomass can be made. This guide provides quick explanation of how Cibo Labs carries out the calibration and field survey process where calibrations are not currently available for specific pasture types.

 

 

  1. Follow the EC20 User guide to set up your device and get the plate meter “talking” to your device.

  2. You will need the following equipment:

    1. EC20 Plate meter

    2. Electric clippers (recommend Stihl). Having a sharp knife is also handy for long tropical pastures.

    3. 3 x 0.1sqm Quadrats made from PVC. These can be a round quadrat with a diameter of 35.7cm or square quadrat inside width of 31.6cm

    4. Large plastic freezer bags (~33cm) or paper bags for collecting wet weight cuts

    5. Smaller paper bags for collecting samples for oven drying to calculate moisture content and Dry Matter %.

    6. Bulldog clips and thick felt marker pen.

  3. Selecting Sampling Sites - Remember the process we are undertaking here is not for completing a paddock survey using the EC20, but rather to rapidly collect field biomass data at specific GPS locations for calibration of remote sensing.

    1. Identify your primary pasture types across the property.

    2. Identify several paddocks that are representative of the important pasture types and grazing regimes. This includes “mixed” pastures.

    3. Identify some low, medium and high biomass areas in those paddocks using the Cibo imagery. See the image below. Remember you can save the Cibo Web Map to the home screen of your phone and click the location buttom on the top left. Select sites that are easily accessed by a vehicle. Sites must also be at least 50-100m away from roads or other significant boundaries.

    4. Avoid rank pastures that won’t compress and recently grazed paddocks.

 

 

  1. Completing the EC20 transects – Once you have identified the pasture types for which calibrations on sites are going to be undertaken, we’re ready to complete the EC20 transects.

    1. Open the EC20 App

    2. Select [SETTINGS]->[EQUATIONS]->”pick equation”. Remember for the first survey this “default equation” is unlikely to provide accurate estimates.

    3. Select [WALK]->[Add or select farm]

  • Use the following naming convention: <WINDY><date> .e.g Windy20200227

  • This is important because it will allow you to export data for a specific date later

  • Enter [Residual]=0.

Select [Paddock]

  • We are using this to identify a “site” rather than a paddock and we simply want the time and pasture type recorded against the name. We need the pasture type to apply the appropriate equation later. Use the following naming convention: <time><pasture_type> e.g 1124mitchell.

  • Enter [Ha]=1

  1. You are ready to start a transect. The idea is to traverse around the “low”, “medium” and “high” sites previously identified in the imagery.

 

Start the Transect with Survey123 form and select the Platemeter Sampling option

For each 'plonk' record the Platemeter Height (cm) as centimeters, convert the displayed heights from the platemeter to cm.

 

Click the '+' when standing at the new plonk location, then enter the readings.

  1. Pick a target and walk in that direction as straight as possible, taking EC20 readings (plonks) at each step. When the EC20 gets to 30 readings – STOP and save the transect. Each transect should be around 25m long.

  2. Walk ahead until you see a change in the pasture biomass and then enter a new [paddock/site] name. 1129mitchell, and so on

  3. Repeat the above with the objective of sampling across range of biomass levels for that pasture type.

  4. Keep an eye on the range of height readings as you do the transects. Remember, the biomass reading you are getting from the default equation is NOT the true biomass.

  5. Calculate the DM yield (kgDM/ha) - by multiplying your Wet Weights by DM%.

    1. e.g Wet Weight = 1500kg/ha x 0.7 (DM%) = 1050 kgDM/ha.

    2. Enter the DM weights back into the Quadrat pasture cuts spreadsheet.

  6. Export and send the transects from the EC20

  7. Select [Reports]->[<Farm>date>] e.g Windy20200227.

  8. Select All ->select the share icon on the top right of the screen and email that to yourself and info@cibolabs.com.au

  9. Email the Cuts and DM% spreadsheet to info@cibolabs.com.au

  10. Cibo Labs will generate the EC20 equations from the height, cuts and DM% estimates for each pasture type and then apply to each transect to generate an estimate of TSDM/ha for each transect.

  11. Equations will be created for the EC20 App for future field surveys and the transect data will be used to develop the prediction model from remote sensing.

 

 

These equations will then be loaded into your EC20 for future assessments, noting that we also expect to need a few calibration cuts at different points in the growing season to ensure field data is accurate.

 

date

time

species

Height (mm)

Grams (wet)

Grams (dry)

Kg/ha

200327

1124

PremDigit

130

120

40*

4000

202027

1125

PremDigit

80

60

20*

2000

*entered after oven drying DM% samples (