Reason for the work
We carried out this work to test the idea that, if a system of tramlines was used in grass fields, in much the same way as is commonly used in arable crop production, then grass yields may be greater as a result of reduced soil compaction, compared with a field where movement of field equipment was not restricted. The project was part of a wider programme of work funded by AHDB Dairy [linked].
What was done
SRUC Crichton Royal Farm was the site for the field study, which was allied to complementary work at Harper Adams University and CTF Europe. A 7ha field was divided in two, half receiving controlled traffic practice (CTF) and half where conventional journeys were made. Measurements were taken of the soil conditions and grass yields from both field halves.
Figure 1. GPS movement across a field
Figure 2. Tractor working widths
Results and recommendations
The field using the CTF practice yielded 13.5% more grass, for 2nd and 3rd cut silage, than the field managed in a conventional way. (The different systems were only implemented from 1st cut harvest and not for the whole growing season, meaning that a difference was not expected to be seen at that stage).
Repeated vehicle passes over the same ground was associated with reduced soil quality (in terms of structure) and soil resistance increasing in line with greater frequency of traffic. Over a whole silage production season, the area travelled over by the CTF system was 57% smaller than the area in contact with equipment travel in the conventionally managed field.
The cost benefits of using specific CTF machinery depended on the level and specification of equipment that might be bought to increase the accuracy of controlled systems.
Potential for Controlled Traffic Farming (CTF) in Grass Silage Production: Agronomics, system design and economics (2017). Hargreaves, PR, Peets, Chamen, WCT, White, DR, Misiewicz, PA and Godwin, RJ. Advances in Animal Biosciences: Precision Agriculture (ECPA) 2017, (2017), 8:2, pp 776–781