Controlled traffic for irrigated double cropping in a semi-arid tropical environment: Part 3, Timeliness and trafficability

Timeliness and trafficability were investigated in a research programme undertaken to assess the potential of controlled traffic for irrigated double cropping in a semi-arid tropical environment. Two controlled traffic treatments, using direct drilling and conventional tillage between the traffic lanes, were compared with a conventional tillage system. Controlled traffic with direct drilling provided marked improvements in timeliness, allowing earlier planting opportunities in all seasons of work, compared with both controlled traffic with cultivation and conventional tillage. In a separate experiment, compacted traffic lanes improved access after rainfall. Under the conditions of the experiment, it would have been possible to sow a crop using controlled traffic and direct drilling 7 days after rainfall, whereas 15 days were required to gain access to begin primary tillage on the conventional treatment. The timeliness benefits obtained from a system of controlled traffic and direct drilling were very dependent on seasonal variations. Nevertheless, this work indicated that, to a greater or lesser extent, timeliness benefits could be gained in all seasons. While this may not necessarily lead to a yield increase on an individual crop basis, it reduces the risk of missing a crop, and offers the opportunity to improve the reliability of producing two crops per year in a semi-arid tropical environment.