Methodology for crop sampling in sugar beet

Protocol for sampling in sugar beet

1. Objetivo

The objective of this instruction guide is to establish the methodology for taking samples in sugar beet that will be followed to carry out the sucrose estimation project.

2. Desarrollo

1. Protocolo de campo

  • Material

  • Mobile phone or tablet. Internet connection is not essential.

  • 2 stakes

  • 2 and 4-meter length rope joined from stake to stake or meter.

  • Sample bag

  • Permanent marker

  • Tags generated by sugar mill

  • Pico

  • Hook

  • Data to collect:

  • Sample ID identifier to be able to reference it later.

  • Plant count per sample

  • Number of linear meters sampled

  • Observations about the sample regarding pests, crop status, etc.

2. Características de las muestras

Study plots

Due to the high number of plots included in the study, a selection has been proposed to ensure that plots from different areas are included and the samples are heterogeneous, thus ensuring representativeness.

Based on the selection of these plots, Azucarera will provide the technicians who are going to sample with the labels generated by its system related to the study plot. There will be two labels, one for inside the bag and one for outside. Below is an example of a label generated by the system.

Illustration 1
Ilustración 1: Ejemplo de etiqueta generada por el sistema.

These labels will go inside a bag, which will be used to collect the sample corresponding to that plot. It should include:

  • Farmer’s GA (Sugar Mill.

  • Grower’s name (Sugar company).

  • Plot ID (Sugar Company)

  • Hemav census ID (Hemav pilot). With a permanent marker, write on the envelope the number corresponding to the identification of the sample from which the leaves were taken. This is a numerical reference.

Number of samples per plot and location

The selection will be made from the PCD map that shows intraplot variability, where the different classes, in this case 5, correspond to areas of differential vigor. The objective is to select the minimum possible samples that are representative of the field, therefore a minimum of 3 samples per plot will be taken, each from a different class

The parameters to consider for sample selection are the following:

  • Sample heterogeneity: each sample must be from a different class according to its vigor.

  • Homogeneity of the area: sample areas must be homogeneous.

  • Plot area: In larger plots, the number of required samples increases.

  • Distance to the plot boundary: Edge effect should be avoided.

The standards for selection are:

  1. Samples should be taken from at least 3 classes whenever possible. If this is difficult or such heterogeneity does not exist in the field, another sample from the predominant group will be taken.

  2. Sample areas must correspond to homogeneous zones, meaning that in the vigor map the sample class should predominate as shown in the image. For example, in the image the red color appears several times, but the sample should be taken in the most representative or extensive area. The same applies to the rest of the colors.

  3. The sample should be positioned as centered as possible within the plot to avoid edge effects. Therefore, no sample should be located less than 10 meters from the plot boundary.

Illustration 2
Ilustración 2: ejeplo de zonas homogéneas de vigor alto, medio y bajo.

Example of possible cases:

– 5 colors are differentiated: If the plot to be sampled is large, 5 samples should be taken, 1 for each color. In the case of a small plot, 3 samples are sufficient and sampling should be done in those colors with greater representation, that is, those that are most predominant in the plot.

– 4 colors are distinguished: As in the previous case, if the plot to be sampled is large, 4 samples should be taken, 1 for each color. In the case of a small plot, 3 samples are sufficient. Sampling should be done in those colors with greater representation, that is, those that predominate most in the plot, therefore ignoring the least predominant color.

– 3 colors are distinguished: A total of 3 samples are taken, one in each area of different color. If it is a very large plot, 2 samples should be taken in the predominant color area.

–2 colors are differentiated: We first ensure that the RGB layer has no clouds or shadows as this is usually one of the main reasons for lack of representativeness. In the absence of clouds, take a total of 3 samples. Take 2 samples in the predominant color (preferably at a distance from each other) and a 3rd sample in the non-predominant color area.

– Only one color is distinguished: We first make sure that the RGB layer has no clouds or shadows as this is usually one of the main reasons for lack of representativeness. In the absence of clouds, take 3 samples distributed throughout the plot

Sample area selection (Linear meters per sample)

When possible, each sample will cover 2 linear meters of crop. The linear meters will only be modified in the following cases:

– Fase temprana del cultivo, La remolacha es muy es muy pequeña y para poder triturarla y hacer “la papilla” se necesitan 10 kg aprox. Cuando el conjunto de remolachas de 2 metros lineales no alcance este peso mínimo, se puede llegar a ampliar el área de muestreo hasta 4 metros lineales, siempre y cuando quede indicado.

– Problems in sugar beet transport

When the beet is in the final phase of cultivation, due to its large volume, it can be reduced but the sample should never be less than 2 linear meters.

Sampling time:

In order to study the relationship between spectral data obtained with drone and laboratory data, no more than 5 days should elapse from when the flight is conducted until sample collection. It is very important that the flight is performed before collecting the sample to obtain spectral information from it before it has been pulled out.

3. Recogida de muestras

  • Locate the different crop classes in the water allocation APP using the PCD layer or default layer

Illustration 3
Ilustración 3: Leyenda del mapa de vigor

  • Locate the crop row where the sampling will be carried out, taking into account that it must be situated at least 10 meters away from the plot boundary.

  • Place a first stake and from this point stretch the 2-meter string until taut, following the same crop line. Where the string ends, drive the second stake to mark off the study area.

  • Collect the beets included in the sampling and put them in the sack.

  • Create a point with the HEMAV gauging APP in the center of the 2 linear meters of the sample.

  • Introducir la siguiente información en “Apuntes del aforo” de la APP

  • Sample identifier: To be able to link the samples, you must add in the APP the sugar refinery reference that appears on the label. For example: 22-M-00001-1

  • Linear meters represented by each sample

  • Plant count per linear meters.

  • Sample color: In relation to the vigor of the sample.

Example for the label in illustration 2 with 2 linear meters of sampling, 15 beets, and dark blue area: 22-M00001-1;2m;15;Blue

Illustration 4
Illustración 4: Añadir información en l aplicación apartado “Apuntes del aforo”

  • Write in the bag the capacity identifier generated in the capacity application.

  • Repeat the procedure for the rest of the plot samples (At least 3 samples per plot to be representative).

  • Send the samples to the laboratory as soon as possible.

  • Return of unused labels: When root samples are delivered to the laboratory, it is very important that the technician returns any unused labels, if any, in order to maintain control.

Mas Información sobre manejo de aplicación: Layers App