Agroscope, Institute for Sustainability Sciences ISS (International Conference of Agricultural Engineering, Zurich, 2014)
Aim of this study was to identify the influence of the parameters compacting time, weight of compacting tractor and tyre section width on the achievable compaction rate in grass silage.
Grass silage compaction in horizontal silos
Latsch Roy and Sauter Joachim
Agroscope , CH-8356 Ettenhausen; www.agroscope.ch
Conclusions
- Heterogeneity of bulk density is one main problem.
- Forage distribution should be improved.
- Creating thin even layer is essential.
- Silage spreaders should be used for good forage distribution.
Operating hight of sensors 6 m
6 m
Ultrasonic sensors
A B C
GPS
2,5 bar
2,5 bar 10 t
John Deere 6920
Tyre dimension 650/65R38 540/65R28 20.8R38 16.9R28 Position rear left front left rear right front right Compacting area
(Width)
A (1.89 m) C (1.77 m)
B (2.34 m)
Tyre section width [mm] 642 520 553 429
Wheel load [kg] 2980 2130 2910 2170
Contact area [cm2] 4667.6 4346.6 3720.0 2977.2
Contact pressure [kg/cm2] 0.638 0.490 0.782 0.729
Results
- Silos had good to very good compacting work quality compared to minimal compaction values (Honig 1991) - Almost identical calculated bulk density vs. median
drilling sample density
- Enormous heterogeneity in bulk density in one and the same height
- No spatial structuring within the layers of the same height inside the silo
- No significant differences between the bulk density in compacting Area A, B or C
- No verifiable effects of different tyre dimensions on bulk density under given conditions
- No significant interaction between bulk density and compacting time
- Extra compacting time in Area B does not lead to better bulk density values
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6
50 100 150 200 250 300
Height [m]
Bulk density [kg DM/m3] 1. Silo 2010
Compacting area A Compacting area B Compacting area C Mean value A Mean value B Mean value C
Materials and methods
Four horizontal silos (W x L x H: 6 x 25.6 x 1.8 metres) were filled with grass and compacted with a tractor of 10.1t weight and different tyre section width on each side.
Therefore three different compacting areas A,B and C occurred.
Selection of collected data:
- original substance (OS) and dry matter content (DM) - position of compacting tractor (via RTK-GNSS logger) - compacting time related to the compacting areas - pile height linearly scanned by 6 ultrasonic sensors - location and density of drilling samples (spaced 20 cm) - retention time and number
- passages of the compacting tractor per wagonload
00:00 05:00 10:00 15:00 20:00 25:00 30:00
A B C
Compacting area Compacting time/Forage mass [mm:ss/t OS]
50 % of values 25 % of values
25 % of values Median
