Dry matter sensor on forage harvester receives the tick of approval

The German Agricultural Society has awarded its prestigious ‘DLG approved’ quality mark to the dry matter yield sensor found on CLAAS JAGUAR forage harvesters.

The sensor uses near-infrared (NIR) technology to provide highly accurate, real-time measurements of the dry matter content, fibre, protein, fat, ash and sugar content of chopped forage as it is blown out the discharge spout. The sensor emits more than 200 pulses of light per second and then measures the spectrum of the reflected light. This data is then compared with a calibration model to determine the dry matter content.

Dry matter and yield content are continuously displayed on CEBIS terminal, allowing the operator to adjust chopping length and the inoculant application rate to suit prevailing conditions. CLAAS claims the technology can accurately measure dry matter content in maize crops ranging from 20 to 60 percent dry matter and pastures ranging from 24 to 65 percent dry matter at crop flows of more than 50 t/hour.

In May last year, DLG tested the accuracy of a NIR sensor fitted to a CLAAS JAGUAR 860 forage harvester, which was used to harvest four fields sown to Italian or perennial ryegrass.

Ten wagons of forage were collected from each crop, with composite samples taken from each wagon as it unloaded. The dry matter content of the 40 samples was determined in a test laboratory using the industry-standard oven-drying method. Dry matter content of the samples ranged from 27 to 45 percent. Laboratory results were then paired with corresponding sensor readings from the NIR sensor.

CLAAS Harvest Centre General Manager of Product – Tim Needham, says the NIR sensor proved itself to be amazingly accurate.

“The difference between the sensor and lab results was less than three percent in all data pairs,” Tim says.

“In 23 of the 40 data pairs, the difference was less than one percent; five were less than two percent, while none of the sensor readings exceeded the tolerated variation by more four percent.

“This is an amazing result when you consider these readings are being taken in 1/200th of a second, whereas the laboratory test takes several hours.

The Deutsche Landwirtschafts-Gesellschaft (DLG) is a not-for-profit organisation that promotes technical and scientific progress within the agricultural and food sectors.

The 135-year-old organisation is best-known for staging Agritechnica, Europe’s leading agricultural exhibition, and for testing dozens of machinery and farm inputs at its agricultural evaluation facility each year.

For more information on CLAAS JAGUAR Forage Harvesters featuring NIR Sensor technology, click here.