Topdressing fertilization for sugarcane

1. Objetivo

This guide aims to show the workflow that must be followed to obtain a deliverable for top-dressing fertilization in sugarcane cultivation. Both the process for satellite in Layers and for drone are explained.

2. Satélite

2.1 No samples

For the preparation of the topdressing fertilization deliverable, for sugarcane cultivation, with satellite as the base layer and without foliar samples to adjust dosage, the following steps must be followed:

  • Find the plot of interest in Layers

Figure 1. Select cover deliverable

  • Select the date closest to the present that does not contain clouds. You must enter the kg of the product you want to apply (in kg/ha) and its richness. You must also select the strategy to follow (optimize, invest or save). When optimizing, it attempts to homogenize the field so that the entire field tends to be in the middle class. Thus, in high vigor areas, it is recommended to apply less fertilizer and in lower vigor areas, it is recommended to apply more. In the invest strategy, it attempts to apply in areas where vigor is lower, and in the save strategy, it attempts to apply in areas that show higher vegetative vigor (ignoring areas of lower vigor).

  • Select the class for which we define the kg/ha we want to apply. By default, medium class is defined. If we select minimum class, the input amount will be considered the minimum contribution we want to make. If, on the contrary, we select maximum class, it will be considered that the indicated contribution corresponds to the maximum that we want to apply in the field. In these cases where we do not select the contribution as medium class, the dosage is corrected as follows:

    • We select middle class

    • Upper class: +20%

    • Middle class: the contribution we indicate

    • Lower class: -20%

    • Selected lower class

    • Upper class: +20%

    • Middle class: +10%

    • Lower class: the contribution we indicated

    • Selected high class

    • Upper class: the contribution we indicate

    • Middle class: -10%

    • Lower class: -20%

  • The resolution parameter refers to the pixel size of the resulting Shp.

Figure 2. Top dressing parameters

  • Once we have all the parameters defined, a deliverable is requested in PDF format or Shp format (if we want/can input it into the tractor we have for variable fertilization).

Figure 3. Deliverable in PDF format

Figure 4. Deliverable in Shp format

2.2 With samples

For the creation of the topdressing fertilization deliverable, for sugarcane cultivation, with satellite imagery as the base layer and foliar samples to adjust the dosage, the following steps must be followed:

  • Locate the plot of interest in Layers.

  • Select the date closest to the sampling that does not contain clouds (not more than 20 days away from the foliar sampling date [before or after]). The same information must be entered as we would enter in the case of coverage without samples. Note that in order to correct the dosage with foliar samples, the laboratory results must have been previously entered through the Hemav gauging APP.

3. Dron

To request this deliverable, you must mark ‘fertilization recommendation’ in MOM and, for now, inform the reference KAM that foliar sampling data has been entered in the sampling APP so that it can be notified to the processing department since, at present, dosage correction with samples is not automatic.

3.1 No samples

If you want a top-dressing fertilizer deliverable using drone flight data as the base layer, but you don’t have samples, a dosage calculation will be performed. The client must enter in MOM the dosage they plan to apply (same as in Layers). With this information, the amount of fertilizer to be applied in the field is adjusted considering the classes found in each zone (see table 1).

3.2 With samples

If a topdressing subscription deliverable is desired, using the data provided by the drone flight as the base layer, and we have foliar measurements, an adjustment will be made to the dosage that the client indicates in MOM. To request this deliverable, it is necessary to have entered, through the measurement APP, the results provided by the laboratory. Note that a minimum of one sample per class (5 samples) is needed for each plot.

Translation: Once we have this data, the procedure to follow is:

  • The average of these samples is calculated for each macronutrient.

  • The class in which these samples are included is determined (from deficient to excessive).

  • Apply the appropriate corrective treatment to the samples and calculate the kg/ha that need to be applied (see table 2).

  • It is entered into our system and correction by zones is applied through drone flight.

4. Correciones según clase

4.1 No samples

The correction applied to the dosage that the client enters is made depending on which class each zone belongs to. Zones that present, for example, excessive content of a macronutrient will have a correction applied to reduce the amount of fertilizer to be applied. The objective of these top dressings is to homogenize the entire plot and save on fertilizer.

The following table summarizes the corrections, by class, that are applied for N, P and K.

Table 1. Corrections by class (%) for plots without foliar samples

4.2 With samples

To perform the correction in plots that do have foliar samples, the same logic is followed as in the correction of those without samples. Each zone of the plot is defined in its class (from deficient to excessive), according to tables verified with bibliography, and the appropriate corrective is applied. The objective of these top dressings is to homogenize the entire plot and save on fertilizer. Note that a minimum of one sample per class (5 samples) is needed for the preparation of this deliverable.

In the following table, the different ranges for classifying sugarcane according to N, P, and K content (in %) are shown:

Table 2. Corrections by class and macronutrient content (%) for plots with foliar samples