SA01WB-02 Site selection layout & drainage | SA05WB-02: Management erosion and sedimentation

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Research Site/Demonstration Number: SA01WB-02 and SA05WB-02
Grower Collaborator: Littabella Pines
Location 2: South Littabella Road, Yandaran
Start Date: April 2019

PHASE 1

OUTLINE

To evaluate the use of aerial imagery, topographic maps and/or in-field surveying to establish better layout of pineapple blocks incorporating contour drains and other erosion management practices to mitigate off-farm deposition in moderate to heavy soil types.

OBJECTIVES

To compare the different methodologies of implementing better farm layout practices using aerial imagery, topographic maps and/or in field surveying.
To reduce off farm deposition of moderate to highly erosible soil types.
To improve surface water flow and soil drainage reducing key pest issues such as Phytophthora root rot.
To increase yield in plant and ratoon crops.
To identify additional advantages to keeping soil in-field and positive effects on cost of production.

PHASE 2

OUTLINE

To evaluate the benefits of different erosion products and practices in-field and out-field to manage surface and subsurface off-farm deposition in low to medium textured soil types and slopes.

OBJECTIVES

To improve the methodologies of implementing better surface and sub-surface erosion practices.
To evaluate different anti-erosion products and their impact on mitigating soil erosion.
To identify additional advantages to maintaining soil in-field and positive effects on cost of production.
To evaluate methodologies for capturing, managing and treating surface water to reduce the loss of soil, pesticides and nutrients.

METHODOLOGY

The trial site is strategically located draining into Littabella Creek and subsequently into a High Environmental Value (HEV) area – the Great Barrier Reef marine park.

The soil was prepared to standard industry conditions with good soil tilth, no crop residue and good soil moisture with a soil pH of 4.3.

Trial site – prior to treatments

Contour map of trial location (image courtesy of Central Queensland University).

PHASE ONE

Aerial imagery taken from a drone (courtesy of the University of Central Queensland) was used to survey the site for three different field layouts:

Treatment 1A – beds planted up and over slopes with no contour banks (standard practice),

Treatment 1B– beds planted to contours on 1-2% slope, and

Treatment 1C – beds planted down slope separated by contour drains / banks on 1-2% slope.

Field Layouts 3 months after planting:

PHASE TWO

Aerial imagery taken from a drone was used to survey the site for three different primary drainage locations and layouts:

Treatment 2A – open drain with no ground cover with a silt trap at the bottom (standard practice),

Treatment 2B – open drain with Geofabric as ground cover, segregated by gabian basket levy banks with a silt trap at the bottom,

Treatment 2C – open drain with Dute Mesh as ground cover planted with sorghum with a silt trap at the bottom.

Treatment 2B:

Treatment 2C:

ASSESSMENT / EVALUATION METHOD AND DELIVERY SCHEDULE

Phase 1

Phase 2

PROGRESS REPORT

May 2019

Block was land prepped
Pre-plant pesticide and nutrition applied

June 2019

Bed-formed
Initial demonstrations applied.
Site planted

Oct 19

Treatments were installed

Feb 20

First assessment – Phase 1
Observations – Phase 2

ISSUES ENCOUNTERED

Delayed start awaiting outcomes of DES findings for further monitoring sites across industry mitigating off-farm deposition.

OTHER NOTES

Site has been selected for its strategic location – it drains into Littabella Creek which runs into the nearby ocean with the Great Barrier Reef off-shore. Staff are collaborating with Growcom and DAF with on-farm initiatives in this trial.

RESULTS

PHASE 1

Soil erosion levels were measured using metal troughs buried at the edge of the pineapple fields in each treatment. Two metres of plastic sheeting were laid on the surface of the ground and seed beds leading into the troughs. The plastic sheeting allowed unobstructed flow of water and sediment directly into the troughs. The troughs captured water at each rainfall event and once the water had evaporated the sediment remained in the trough.

From the period of April 2019 to November 2019 there were no rainfall events. However, from late December 2019 to February 2020 a significant number of rainfall events occurred throughout this period.

The following results were measured in February 2020 (10 months after planting):

Key Points:

Significantly high amount of soil erosion in the standard practices, lowest soil erosion in pineapples planted along the 1% contour and moderate to high levels soil erosion in the treatment with pineapples planted down slope separated by contour drains / banks.
Both standard and pineapples planted along the 1% contour treatment – soil erosion was captured on the edge of field (outside the block).
The treatment with pineapples planted down slope separated by contour drains / banks sediment was captured within the block by the contour banks / drains.
Clear, visible signs of waterlogging were observed in the treatment with pineapples planted along the 1% contour which would lead to issues of phytophthora root rot.

Treatment 1A:

High amounts of sediment captured by metal troughs

Treatment 1B:

Low amounts of sediment – Potential water logging in field

PHASE 2

Treatment 2B

Sediment from Treatment 1A – beds planted up and over slopes with no contour banks (standard practice) captured in primary drain by gabian basket levy banks.

Sediment captured in primary drain – Sediment removed from primary drain