Improving Internal Soil Drainage

Improvement of internal soil drainage and yield on heavy soils in the Herbert

Objectives:

The Herbert consists of large areas of clay soils being sugarcane farmed within the region. These soils are usually nutritionally fertile; however yield potential is limited due to waterlogging. Surface drainage has been improved through laser levelling, however yield potential is not fully realised due to limitations associated with internal soil drainage. Mole draining has been undertaken in the region in the past with varying success because of the inability of the mole drain to be positioned away from trafficked areas (traffic can caused the mole drain to collapse when trafficked upon). With the availability of GPS systems growers can now determine the exact position of the mole drain below a cane row on controlled traffic farming system blocks.

This project will investigate 3 methods to potentially increase internal soil drainage and cane yields. If the concepts are proven in the project, it has the opportunity to be extended to other farms within the region with similar problems.

Project Activities:

The project intends to establish a trial in the Warren's Hill area (outside of Ingham) to assess the following treatments:

• Zonal application of mill ash below the soil surface- to improve internal soil drainage and crop establishment. The zonal strips will be applied using GPS technology to ensure that applications are undertaken within the root zone of the plant. Row spacing 1.8m.
• GPS positioned mole drainage line (filled with coarse sand or some other porous material) located directly below the cane row on a permanent 1.8m bed system. Mole drains have worked effectively in the industry, however location of these drainage lines have never been geographically positioned in a field using GPS and used in a permanent bed system.
• GPS positioned agricultural pipe (5cm diameter) located directly blow the cane row on a permanent 1.8m bed system. Agricultural pipes have worked effectively in the industry, however location of these drainage lines have never been geographically positioned in a field using GPS and used in a permanent bed system.
• A single leg deep ripping below the cane row using zonal tillage.
• Control treatment where-by "traditional" practices are undertaken and will allow for a comparison. This treatment would consist of conventional tillage practices (like ripping, discing and rotary hoeing across the field).

All treatments will be planted on a 1.8m controlled traffic configuration.

The sub-surface mole drainage equipment will be hired from T & G Drains (in Victoria) for the project. Relocation costs from Victoria will be met as a part of the project. After further investigation throughout Australia there were no other such units available closer to the Herbert available for the project.

It is proposed that the trial will consist of a minimum of 2 replicates and 5 treatments.

A nutrient balance of all treatments will be undertaken to account for nutrients applied in each treatment. Soil ameliorants will only be applied if a soil test indicates the soil requires it.

The trial will be analysed for cane yield, CCS, soil moisture, soil and leaf testing results, water quality exports from field, economic cost for each treatment and a cost benefit analysis undertaken. Yields in plant and 1^st ratoon will be assessed by the project.

Contact Person: Chris Bosworth 0418 983 507