Grassed inter-rows in bananas in the Wet Tropics region

Key findings

  • Improved management practices in bananas have reduced the cost of fertiliser application. In addition, grassed inter-rows have reduced the loss of water and sediment.

About this case study

Bananas are an important crop in the Wet Tropics and are grown on 11,000 hectares. High rates of nitrogen loss in deep drainage have previously been measured from paddocks receiving high rates of fertiliser nitrogen. Since 1995, nitrogen application rates used by the industry have reduced by as much as 40 per cent (Sing 2012).

Results

The reduced rate and more frequent application of nitrogen under B class management practice produced similar yield, fruit characteristics and ‘follower' sucker growth to that achieved under conventional management. These lower rates of fertiliser application have already been adopted on commercial plantations by some growers without affecting productivity.

Banana bunch weight and sucker height graph

Graph data (CSV, 81.0Bytes)

Open larger image

B class practice, February 2010. Photographer: John Armour, Department of Natural Resources and Mines.

Open larger image

C class practice, February 2010. Photographer: John Armour, Department of Natural Resources and Mines.

The cost of nitrogen fertiliser was $220 per hectare for the B class management practice and $365 per hectare for the C class management practice, a saving of $145 per hectare for the plant crop. In addition, by using fertigation, the B class practice also reduced the application cost by omitting one pass of a tractor and fertiliser spreader each month.

The photographs below were taken minutes apart during a rainfall event in February 2010 before the installation of monitoring equipment was completed. They clearly demonstrate the difference grassed inter-rows make. The B class management practice, with the grassed inter-rows, has no water and sediment movement in contrast to the high (unquantified) sediment load in runoff from bare inter-rows of the C class management practice. However, the grassed inter-rows are difficult to maintain in ratoon crops because of constant traffic and increased shading.

The Paddock to Reef program will continue to measure runoff, sediment and water quality resulting from these two treatments, and gather more information on the productivity and economics of the B and C management practices. For further information on improved banana management practices, see the Monitoring nitrogen losses from bananas in the Wet Tropics region case study.

References

Sing, N.C. (2012). Banana Voluntary Adoption Survey Results, Terrain NRM, March 2012.

Authors

John Armour, Bronwyn Masters and Christina Mortimore (Queensland Government Department of Natural Resources and Mines).

Partners

  • Australian Government Caring for our Country Reef Rescue initiative
  • Queensland Government Department of Natural Resources and Mines