The Grasshopper sensor unit can be used with an existing Jenquip plate by adding an adapter clip. The location it is mounted on the Jenquip is defined by the clip moulding. Any variations are elminitaed when the plate meter auto-calibrates on Grasshopper sensor power-up.
Grasshopper takes a series of samples across the paddock being surveyed. Each sample is tagged with a date, time (to the second), and it's geo-location. The sample is the compressed height of the grass at the sample point. When reviewing sample data it is possible to review any single sample, a small area, or the paddock as a whole.
An average paddock will require an adequate number of samples - this varies with two factors - the overall paddock area and the uniformity of growth. Sample numbers may be set automatically (the Grasshopper knows which paddock it is in without being told) or manually at the start of the survey. It is recommended to preset the sample number to save time on the survey.
Geo-tagging is the attachment of lattitude and longitude information to the sample. This information is unique to every sample and will have an accuracy of 1 - 1.5m depending on location and the GPS constellation at the time the sample was taken. Geo-tagging allows data analysis based on defined ares.
All survey files are kept on the smart device. Eventually you will run out of space if the files are not moved on.
Your paddock list is input during the setup phase for your Grasshopper. A paddock ID is assigned to each paddock and retained in a separate file which is read every time a survey is undertaken.
Yes, a farm map is required. This can be generated by a supplier or it may be genrated on the farm using Grasshopper. Each paddock needs to be geo-coded so that Grasshopper knows where it is during subsequent surveys.
The live dry-matter measure is a function of the amount of grass, the moisture content at time of measure, and the time of year - or more correctly the stage in the season. After grass volume measurement, the moisture content is by far the most critical of these inputs. The accuracy will largely depend on the accuracy of the moisture figure entered. This input is required at the begining of each survey.
Managing paddock utilisation is up to you as farm manager. Grasshopper will provide your weekly 'wedge', utilising an online service such as Teagasc - 'Pasture Base' or 'Agrinet' is recommended for management purposes.