Farming systems and production management

Monitoring of groundwater levels has been undertaken in the Ord River Irrigation Area using a network of bores established on farms throughout the Stage I area. These bores, many of which were installed as part of this project, complement a network previously established off farm. They have been monitored on a regular basis and changes in levels have been examined in relation to a range of factors including irrigation and crop management practices, rainfall and irrigation infrastructure management, to allow causal relationships to be established and hence potential management strategies to be developed. Monitoring has been assisted through the equipping of many bores with water depth probes and loggers to automatically record changes in levels over extended periods of time.

The potential agronomic and environmental benefits of green cane harvesting and trash blanketing, the ongoing issues of nutrients and pesticides threatening the Great Barrier Reef, the rising ground water levels in the area, and water use efficiency issues, prompted the progressive MAFIA grower group to conceptualise a project to trial alternative irrigation systems and compare them with the conventional furrow irrigation system. A lateral move irrigation system was established on the Hesp property, in the Mulgrave farming area in the Burdekin, to irrigate sugarcane throughout a full 4 year crop cycle. This system was compared to conventional furrow and, on a nearby property, a drip irrigation system. The sites were extensively instrumented to measure parameters that would enable the water and nutrient balance to be monitored on the furrow and lateral move irrigated fields. Importantly, an intensive economic analysis was conducted to provide a guide to the economic evaluation of the three systems. Overall the results of the trial indicated that it was indeed possible to grow large sugarcane crops under the lateral move and drip irrigation systems, and that these crops could be subsequently harvested green. It was shown that the lateral move and drip systems also provided opportunity for improved water use efficiency over the furrow irrigation system and that the subsequent flow on benefits from this was reduced loss of nutrients via deep drainage and irrigation runoff. The economic evaluation, using actual inputs costs from the trial sites, show that the furrow and lateral move had similar operating costs which were significantly less than the drip system. However, it should be pointed out that this economic study looked at the adoption of a new irrigation system versus an existing furrow irrigation system. If the analysis was to examine a greenfield investment comparison, then the economic results could significantly change because of the extra capital investment required to establish a furrow irrigation system. In this analysis, environmental benefits resulting from improved water, nutrient and pesticide use are not accounted for in dollar terms, but if included would recognise the value of more efficient farming systems. While every effort was made to provide reliable information from this study, constraints associated with conducting the trial, within an existing “whole of farm” operation, meant that it should be considered more as a pilot study rather than a rigorous scientific trial. For this reason care should be taken in extrapolating the data from this study to other properties or areas where different circumstances and constraints could alter the perspective significantly.

In the late 1980’s the Burdekin dam commenced operation and resulted in a large area of land being cleared and converted to irrigation. This influx of water has caused the groundwater level to rise alarmingly over the past 20 years from its previous level typically 10 to 15 meters below the surface to around 0.5m in some places in 2009. This is an alarming increase and if not rectified and reversed quickly will lead to significant crop losses and is likely to render some land unviable for farming in the next 5 years.

Farming systems and production management

Browse

Filters

Advanced Search

Filter by

Settings

Sort By

Results per page

Search Results