1.3 Conditions relatives à l'utilisation par WOCAT des données documentées

Quand les données ont-elles été compilées (sur le terrain)?

01/09/2005

Le compilateur et la(les) personne(s) ressource(s) acceptent les conditions relatives à l'utilisation par WOCAT des données documentées:

Oui

2.1 Courte description de la Technologie

Définition de la Technologie:

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 Description détaillée de la Technologie

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 de la Technologie

2.5 Pays/ région/ lieux où la Technologie a été appliquée et qui sont couverts par cette évaluation

3.2 Type(s) actuel(s) d'utilisation des terres, là où la Technologie est appliquée

Commentaires:

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 Informations complémentaires sur l'utilisation des terres

Approvisionnement en eau des terres sur lesquelles est appliquée la Technologie:

• pluvial

Nombre de période de croissance par an: :

• 1

Précisez:

Longest growing period in days: 300

Longest growing period from month to month: Aug - May

3.5 Diffusion de la Technologie

Commentaires:

Total area covered by the SLM Technology is 800 m2.

Wet tropics region of far north Queensland

3.6 Mesures de GDT constituant la Technologie

3.7 Principaux types de dégradation des terres traités par la Technologie

Commentaires:

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 Prévention, réduction de la dégradation ou réhabilitation des terres dégradées

Spécifiez l'objectif de la Technologie au regard de la dégradation des terres:

• réduire la dégradation des terres

Commentaires:

Main goals: mitigation / reduction of land degradation

4.1 Dessin technique de la Technologie

4.2 Spécification/ explications techniques du dessin technique

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 Informations générales sur le calcul des intrants et des coûts

4.6 Activités d'entretien/ récurrentes

	Activité	Type de mesures	Calendrier/ fréquence
1.	mulching of inter-rows with trash [previously: burn cane with associated trash and then harvest]	Agronomique	August
2.	fertilize cane	Agronomique	October
3.	spray with Amicide (very efficient herbicide, systemic and non-selective)	Agronomique	November
4.	spray with Amicide	Agronomique	January

4.7 Coûts et intrants nécessaires aux activités d'entretien/ récurrentes (par an)

Commentaires:

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 Climat

5.2 Topographie

5.3 Sols

5.6 Caractéristiques des exploitants des terres appliquant la Technologie

Indiquez toute autre caractéristique pertinente des exploitants des terres:

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

5.7 Superficie moyenne des terres détenues ou louées par les exploitants appliquant la Technologie

5.8 Propriété foncière, droits d’utilisation des terres et de l'eau

Propriété foncière:

• individu, avec titre de propriété

Droits d’utilisation des terres:

• individuel

6.1 Impacts sur site que la Technologie a montrés

Impacts socio-économiques

Revenus et coûts

Impacts socioculturels

Impacts écologiques

Cycle de l'eau/ ruissellement

Sols

6.2 Impacts hors site que la Technologie a montrés

6.4 Analyse coûts-bénéfices

Quels sont les bénéfices comparativement aux coûts d'entretien récurrents (du point de vue des exploitants des terres)?

6.5 Adoption de la Technologie

Commentaires:

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 Points forts/ avantages/ possibilités de la Technologie

Points forts/ avantages/ possibilités du point de vue du compilateur ou d'une autre personne ressource clé
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 Faiblesses/ inconvénients/ risques de la Technologie et moyens de les surmonter

Faiblesses/ inconvénients/ risques du point de vue du compilateur ou d'une autre personne ressource clé	Comment peuvent-ils être surmontés?
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 Références des publications disponibles

Titre, auteur, année, 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

Titre, auteur, année, 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

Titre, auteur, année, ISBN:

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