M. Sefton’s scientific contributions

CONCERNS ABOUT decreasing productivity in recent years in the Herbert cane growing region prompted the Herbert Cane Productivity Services Limited (HCPSL) to commission a review of the production system in an attempt to identify issues that have likely influenced productivity. The review encompassed the collation and analysis of productivity data held by HCPSL, interpretation of the analyses and interviews with growers. In general the outcomes indicated that water management (seasonal conditions, drainage, waterlogging), various aspects of harvesting (groups too big, harvesting too fast, not enough adjustment for seasonal conditions/geographic harvesting, cane loss and season length (the harvest season being too long) were the main factors influencing productivity in the Herbert. The review showed that productivity was strongly linked to seasonal conditions with high rainfall in November, in particular, having an adverse effect on crop productivity the next year. This is likely due, at least in part, to radiation limitation, waterlogging, and nutrient loss under the wet conditions. However, the combination of high rainfall in November and harvesting with heavy machinery under wet conditions is also likely to be having a significant adverse effect on productivity the next season, through either direct effects on the ratoons and/or limiting the opportunity for field maintenance between cycles. Of the 23 years since 1989 harvesting has continued into November and/or December in 21 and 19 of those years for Victoria and Macknade mills, respectively. It is suggested that if the harvest season is completed by the end of October the adverse effects on productivity the following year are likely to be substantially reduced. Suggestions are made as to how this may be achieved. Contrary to popular opinion there is no clear evidence that varieties are involved in the season to season variation in yield.

In the Herbert River district, around 8000 bins each day of the crushing are assigned via a paper-based system to the cane block from which they were harvested. The Herbert has 20000 cane blocks. About 3000 errors occur each year during this consignment process, mainly due to human error. These errors cause mill stoppages and can cause cane payment re-work. This pilot study consisted of tracking 4500 tonnes of cane from field to factory for the Girgenti harvesting group for a period of two weeks. By linking and utilising various technologies, the opportunity to provide a paperless system with no manual input was realised. As such, the trial was successful in that it provided a proof of concept for full electronic consignment. There was one hundred percent correlation between the hand written consignment of bin numbers by the field crews and the electronic system's SQL data base. This system has potential to add value to the 'field to factory' supply chain. Importantly it will enable new asset management strategies to be adopted.

SURFACE soil samples have been collected for many years to develop on-farm nutrient management guidelines but their precise locations were largely unknown because geo-referencing technology was previously unavailable. Consequently, spatial analysis of the data was not possible. Over the past four years, the Herbert Cane Productivity Services Limited (HCPSL) has provided a service to growers to co-ordinate soil sample collection, sample analysis, and reporting of soil test information; a geo-referenced position is recorded for every sample. This information is collated in a spatial database and forms a layer in the geographic information systems (GIS) managed jointly by HPCSL and the Herbert Resource Information Centre (HRIC). Interpretation of the data has provided spatial patterns of soil properties across the district. This paper presents examples of the spatial distribution of different nutrients and soil chemical characteristics such as soil pH, extractable phosphorus, cation exchange capacity, exchangeable calcium and extractable aluminium. It shows how georeferenced soil test data can be used to develop nutrient management strategies within the region and to address specific issues associated with nutrient deficiencies and excesses. Copyright © (2009) by Australian Society of Sugar Cane Technologists All rights reserved.