QGIS: Yield Data Manipulations

OVERVIEW

Manual with step-by-step description to resolve the following troubles with data from yield monitor:

1. Missed projection file (.prj) in shapefile

2. Apply conversion rules for every attribute in shapefile (based on kb/ha to bu/ac sample)

The software to utilize is QGIS (LINK).

Downloading and installation are mandatory.

MISSED PROJECTION FILE

1. Open shapefile with yield data. Move the file inside the QGIS window.

2. The shapefile becomes available for further manipulations in the Layers block.

1. Start saving process

2. 1. Do the right mouse button and click at the shapefile

   2. Choose Export -> Save Feature As ...

1. Choose

2. 1. Format -> ESRI Shapefile,

   2. Filename -> click … and select the preferred directory and filename,

   3. CRS -> EPSG:4326

   4. Encoding -> UTF8

   5. Add saved file to map (optional if you want to see it directly in QGIS)

   6. Geometry type -> Point

1. Click Ok

2. An additional shapefile with the same yield data is created. The projection file (.prj) was added.

BU/AC CONVERSION

1. Do the right mouse button click on the shapefile and choose Open Attribute Table

1. Click Open field calculator

1. Create a new field

2. 1. Mark Create a new field

   2. Enter Output field name -> DryYieldBu

   3. Choose Output field type -> Decimal number (real)

   4. Change Precision -> 4

   5. Put rule to convert kg/ha to bu/ac -> "Dry_Yield" * 0.0149

1. Click Ok

2. Additional DryYieldBu attribute has appeared in the table

1. Save the changes

2. 1. Do the right mouse button click on the interested shapefile

   2. Choose Toggle Editing

1. Confirm saving the changes

The interested shapefile is not marked with Pencil anymore. The data in the shapefile was updated.