System design and the economics for Controlled Traffic Farming (CTF) in grass silage production

Abstract. The objectives of this work were to: (i) identify the dry matter (DM) yield increase from non-trafficked soil (ii) review the commercially available grass forage equipment that could form the basis of Controlled Traffic Farming (CTF) systems and (iii) determine the economic value of implementing a CTF system for grass production. An extensive literature review was undertaken which indicated a 13% increase in dry matter (DM) yield in the absence of wheel damage. This was in alignment with experimental results reported here comparing grass DM yield between CTF and normal traffic management (N). Commercially available grass forage equipment with widths of 3, 4, 5, 9 and 12 m reduced trafficked areas from 80%–90% for N to 40%–13% for CTF. Reducing the trafficked area from 80% for N traffic to 15%, increased the yield by up to 1.00 t ha^-1 and 1.36 t ha^-1 for 2 and 3 cut systems, respectively. The value of these yield increases varied between $48 ha^-1 and $125 ha^-1 assuming a DM value of $92 t^-1 for grass silage. The cost ha^-1 year^-1 for four low accuracy manually steered systems is less than $23.85 for areas in excess of 100 ha; for four fully integrated high accuracy steering systems the cost is $109.06 for areas in excess of 200 ha, reducing to $14.54 for areas greater than 1500 ha. CTF for a multi-cut grass silage system is cost-effective in increasing yields due to a reduction in the extent of compaction.