Developing a novel way of rapidly measuring agronomic treatment effects on grass growth

Measuring grass yield is time consuming and laborious because it either involves multiple measurements with a rising plate meter or counting and weighing silage trailers.

Recent studies have demonstrated that spectral reflectance of grass crops measured by satellite could be used to accurately measure grass yield. This method offers a much simpler and quicker method of measuring grass yield that would enable farmers to test the effect of different agronomic treatments in order to optimise their grass husbandry approach. Spectral reflectance imagery captured by drones can now also be used to measure grass growth which can produce finer resolution images however this relies on manual operation.

Three dairy farmers in Monmouthshire have come together to investigate whether these new methods of measuring grass will enable them to reliably and quickly measure grass yields. They’re hoping that this new technology will allow them to measure the effects of different agronomic treatments (fertiliser treatments, grass varieties and the use of herbicide etc.) remotely on their own fields.

The three year project plan:

• Trial plots will be set up on one silage field on each of the three farms
• Each trial plot will test an agronomic treatment - whichever is of greatest interest to the farm in question, which will be replicated and randomised on each field 2-4 times.
• The control treatment will be the farm standard treatment, which the treatments will be trying to improve upon.
• Two to four weeks after the treatment (depending on the type of treatment) has been applied, satellite and drone spectral reflectance imagery of the test fields will be acquired.
• Grass growth will be collected using a rising plate meter at the same time to give the ground truthed data.
• The grass measurements from all three methods will then be compared to test the effects the agronomic treatments had on grass yield.

This project will hopefully highlight the advantages and disadvantages of each grass measurement technique which will allow farmers who wish to utilise this new technology to decide which technique would best suit their system. These new methods could potentially provide a non-labour intensive method of accurately measuring grass which can improve farm viability and competitiveness.