1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

01/09/2005

The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:

Yes

2.1 Short description of the Technology

Definition of the Technology:

Elimination of burning as a pre-harvest treatment of sugar cane, and managing the resultant trash as a protective blanket to give multiple on and off-site benefits.

2.2 Detailed description of the Technology

Description:

Under conventional production systems, sugar cane is burnt before being harvested. This reduces the volume of trash - comprising green leaves, dead leaves and top growth - making harvesting of the cane simpler, and subsequent cultivation of the soil easier. In the humid tropics of North Queensland, harvesting of cane used to be carried out by hand - as it still is in many parts of the developing tropics. Burning was necessary to make harvesting possible in a dense stand (and to reduce the danger of snakes). However, with the advent of mechanical harvesters in the 1960s, burning continued to be practiced through habit.
A new system then brought fundamental changes in soil management: The ‘green cane trash blanket’ (GCTB) technology refers to the practice of harvesting non-burnt cane, and trash blown out behind in rows by the sugar cane harvester. This trash forms a more or less complete blanket over the field. The harvested lines of cane re-grow (‘ratoon’) through this surface cover, and the next year the cycle is repeated: the cane is once again harvested and more trash accumulates in the inter-rows. Generally the basic cropping cycle is the same, whether cane is burnt or not. This involves planting of new cane stock (cuttings or ‘billets’) in the first year, harvesting this ‘plant crop’ in the second year, and then in years three, four, five and six taking successive ‘ratoon’ harvests. In year six, after harvest, it is still common, even under the GCTB system, to burn the residual trash so that the old cane stools can be more easily ploughed out, and the ground ‘worked up’ (cultivated) ready for replanting. A minority of planters, however, are doing away with burning altogether, and ploughing in the residual trash before replanting. A further variation is not to plough out and replant after the harvest in year six, but to spray the old cane stock with glysophate (a broad spectrum non-selective systemic herbicide) to kill it, then to plant a legume (typically soy bean) as a green manure crop, and only replant the subsequent year after ploughing-in the legume. Under this latter system, one year of harvest is lost, but there are added benefits to the structure and nutrient content of the soil.
Whatever variation of GCTB is used, there are advantages in terms of increased organic matter, improved soil structure, more biodiversity (especially below ground) and a marked reduction in surface erosion - from over 50 t/ha to around 5 t/ha on average. Less erosion is good for the growers - but is also of crucial importance off-site, as sediment lost from the coastal sugar cane strip is washed out to sea, and damages the growing coral of the Great Barrier Reef.

2.3 Photos of the Technology

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment

3.2 Current land use type(s) where the Technology is applied

Comments:

Major land use problems (compiler’s opinion): Conventional burning of sugar cane before harvest can lead to compaction of top soil and reduced organic matter. There is also, despite the low slopes, a serious problem of sheet/rill erosion that has a negative impact both on the fields, and also off-site on the coral reef.

Major land use problems (land users’ perception): soil erosion, weeds, flooding

3.3 Further information about land use

Water supply for the land on which the Technology is applied:

• rainfed

Number of growing seasons per year:

• 1

Specify:

Longest growing period in days: 300

Longest growing period from month to month: Aug - May

3.5 Spread of the Technology

Comments:

Total area covered by the SLM Technology is 800 m2.

Wet tropics region of far north Queensland

3.6 SLM measures comprising the Technology

3.7 Main types of land degradation addressed by the Technology

Comments:

Main type of degradation addressed: Wt: loss of topsoil / surface erosion, Wo: offsite degradation effects, Cn: fertility decline and reduced organic matter content

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:

• reduce land degradation

Comments:

Main goals: mitigation / reduction of land degradation

4.1 Technical drawing of the Technology

4.2 Technical specifications/ explanations of technical drawing

Harvester harvesting cane and depositing trash on surface

Location: Queensland

Technical knowledge required for field staff / advisors: low

Technical knowledge required for land users: low

Main technical functions: control of raindrop splash, improvement of ground cover, improvement of soil structure, control of dispersed runoff

Secondary technical functions: increase in organic matter, increase of infiltration, increase in soil fertility, increase in surface roughness

Mulching
Remarks: "trash blanketing"

4.3 General information regarding the calculation of inputs and costs

4.6 Maintenance/ recurrent activities

	Activity	Type of measure	Timing/ frequency
1.	mulching of inter-rows with trash [previously: burn cane with associated trash and then harvest]	Agronomic	August
2.	fertilize cane	Agronomic	October
3.	spray with Amicide (very efficient herbicide, systemic and non-selective)	Agronomic	November
4.	spray with Amicide	Agronomic	January

4.7 Costs and inputs needed for maintenance/ recurrent activities (per year)

Comments:

Machinery/ tools: sugar-cane harvester

The year budgeted above is a non-planting year, the costs therefore refer to an established crop which grows
throughout the year and is harvested in August. The assumption is a cane yield of 80 t/ha. Each of the three categories of costing groups machinery, labour (at US$12 per hour) and inputs together. The comparative costs for a burnt cane crop system with the same yield are (a) contract harvesting = US$ 378 (b) fertilizer = US$ 120 (c) herbicide = US$ 56, plus (d) cultivation = US$ 30. Note that under the burnt cane system, soil cultivation/tillage is required, but the cost of harvesting is a little cheaper. The total for the burnt crop system is US$ 584 compared with US$ 543 for the GCTB crop, representing a saving of approx. US$ 40 (around 7%) per hectare per year.

5.1 Climate

5.2 Topography

5.3 Soils

5.6 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

Off-farm income specification: various off-farm enterprises undertaken to supplement income during years of poor sugar prices

5.7 Average area of land owned or leased by land users applying the Technology

5.8 Land ownership, land use rights, and water use rights

Land ownership:

• individual, titled

Land use rights:

• individual

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Income and costs

Socio-cultural impacts

Ecological impacts

Water cycle/ runoff

Soil

6.2 Off-site impacts the Technology has shown

6.4 Cost-benefit analysis

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?

6.5 Adoption of the Technology

Comments:

95% of land user families have adopted the Technology without any external material support

1000 land user families have adopted the Technology without any external material support

There is a little trend towards spontaneous adoption of the Technology

Comments on adoption trend: It is possible that the few growers who persist in burning will eventually adopt the GCTB system through social and environmental pressure.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
GCTB systems offer multiple on-farm environmental benefits How can they be sustained / enhanced? Continue to refine the system, by encouraging (a) non burning of trash in the
Increases overall farm income by maintaining yields of sugar cane while How can they be sustained / enhanced? Continue to refine the system.
GCTB systems provide protection to the coral reef, through substantially reducing the sediment yield that reaches the lagoon and thence the Great Barrier Reef How can they be sustained / enhanced? Give recognition to the growers for their overall environmental contribution.

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view	How can they be overcome?
Some burning still continues through (a) the few farmers who have not yet adopted GCTB and (b) the common practice of burning trash before replanting	Continue to encourage non-burning for multiple reasons.

7.2 References to available publications

Title, author, year, ISBN:

Mullins JA, Truong PN and Prove BG (1984) Options for controlling soil loss in canelands – some interim values. Proc. Aust. Soc. Sugar Cane Technol., 6: 95–100

Title, author, year, ISBN:

Vallis I, Parton WJ, Keating BA and Wood AW (1996) Simulation of the effects of trash and N fertilizer management on soil organic matter levels and yields of sugarcane. Soil and Tillage Research. 38: 115–132

Title, author, year, ISBN:

Wood AW (1991) Management of crop residues
following green harvesting of sugarcane in north Queensland. Soil Till. Res. 20: 69–85