1.2 Coordonnées des personnes-ressources et des institutions impliquées dans l'évaluation et la documentation de la Technologie

Nom du ou des institutions qui ont facilité la documentation/ l'évaluation de la Technologie (si pertinent)

EEZA-CSIC (EEZA-CSIC) - Espagne

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

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

Oui

1.5 Référence au(x) Questionnaires sur les Approches de GDT (documentées au moyen de WOCAT)

2.1 Courte description de la Technologie

Définition de la Technologie:

Organic mulching to protect against rain-splash, sheet wash and rill formation, reduce evaporation losses and weed growth.

2.2 Description détaillée de la Technologie

Description:

Organic mulch is applied in Almond fields to provide a permanent surface cover that protects the soil against soil erosion, reduces evaporation and limits the growth of weeds. This makes that less ploughing is needed under Almond trees that are normally ploughed 3-5 times per year if no mulch cover is present. The material used for mulching can be diverse. Most feasible are straw or bark and wood chips from pruning residues from almonds and forest species (mostly pines). Alternatively, alpha-grass can be used as mulch. Mulch can best be applied late spring or early summer in order to maintain soil humidity of spring rainfall. Mulch should come mixed and homogenised. It is spread around trees by a mechanical spade or by the arm of a caterpillar. A layer of maximum 3-5 cm of mulch should be applied for economical reasons.

Purpose of the Technology: The ultimate goal of organic mulching under almond trees is to maintain soil water through a reduced evaporation and reduce soil loss by erosion. A mulch covers reduces soil erosion by 1) reducing raindrop impact, 2) increasing water infiltration, 3) increasing surface storage, 4) decreasing runoff velocity, 5) improving soil structure and porosity, and 6) improving the biological activity in the soil. Mulching prevents off-site effects of erosion like flooding, damage to infrastructure and siltation of water reservoirs, while maintaining or slightly increasing crop productivity. The mulch results in a higher soil roughness, a better infiltration of water into the soil, and so also in a reduced runoff. The mulch also has a favorable effect on soil quality since the organic material of the mulch will slowly decompose and provide nutrients to the soil. The decomposing part of the organic mulch will increase aggregation and soil structure through the production of organic compounds (e.g. humic acids). The reduced necessity for ploughing of the Almond fields will result in less fuel use and labour as well as reduced emission of CO2. In addition, the mulch cover prevents weeds to grow and so less competition from weeds will occur and less herbicides are needed.

Establishment / maintenance activities and inputs: The establishment of mulching depends on the material used for mulching. Given its availability, the easiest is the use of pruning residue from Almond trees. Almonds are pruned in autumn, and residue can be chopped and applied directly or stored in the field until early spring. Residues are chopped and spread around the tree stem and if enough material is available between tree stems. Alternatively, and depending on availability, pruning residue of pine trees or alpha-grass can be used. Pine tree residue should come from nearby forest stands and need to be chopped just like the almond pruning residue in spring. Litter from the forest floor should not be used as this will cause damage to the forest. Alpha-grass is very common in the region and should be harvested in winter in the fields surrounding the cultivated area without destroying the plant allowing it to regenerate. The alpha-grass does not need to be chopped and can be put around the tree stem of the almond trees.

Natural / human environment: The technology is feasible for soils of shallow to medium depth (between 20-60 cm), and with gentle to moderate slope gradients (2 - 8%). The climate is semi-arid with a mean annual rainfall around 300 mm. Droughts, centred in summer commonly last for more than 4-5 months. Annual potential evapotranspiration rates larger than 1000 mm are common. The production system is highly mechanised and market oriented but depends strongly on agricultural subsidies. All cropland is privately owned.

2.3 Photos de la Technologie

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

2.6 Date de mise en œuvre de la Technologie

Si l'année précise est inconnue, indiquez la date approximative: :

• il y a entre 10-50 ans

2.7 Introduction de la Technologie

Spécifiez comment la Technologie a été introduite: :

• au cours d'expérimentations / de recherches

Commentaires (type de projet, etc.) :

Mulching is a well-known technique. However, until now not widely applied under semi-arid conditions without irrigation. With irrigation, plastic mulch is widely applied.

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

Les divers types d'utilisation des terres au sein du même unité de terrain: :

Oui

Précisez l'utilisation mixte des terres (cultures/ pâturages/ arbres):

• Agroforesterie

Commentaires:

Major land use problems (compiler’s opinion): A lack of water availability seriously limits the production potential of the soil and results in a low vegetation/crop cover. The relatively high soil erosion rates cause various off-site related problems (i.e. flooding, reservoir siltation) and on-site problems (i.e. gully formation and loss of soil depth).

Major land use problems (land users’ perception): Lack of water for irrigation of crops limiting the crop types that can be planted as well as the crop yield of dryland farming.

Livestock is grazing on crop residues

3.4 Approvisionnement en eau

autre (par ex., post-inondation):

• all three

Commentaires:

Water supply: rainfed, mixed rainfed - irrigated

3.6 Mesures de GDT constituant la Technologie

Commentaires:

Main measures: agronomic measures

Type of agronomic measures: mulching

3.7 Principaux types de dégradation des terres traités par la Technologie

Commentaires:

Main type of degradation addressed: Wt: loss of topsoil / surface erosion, Pk: sealing and crusting, Ha: aridification

Secondary types of degradation addressed: Wo: offsite degradation effects

Main causes of degradation: crop management (annual, perennial, tree/shrub) (Almond fields often have a very low surface cover by vegetation during long periods of the year, due to frequent ploughing, leaving the soil unprotected against raindrop impact and rill or gully forma), disturbance of water cycle (infiltration / runoff) (Reduced infiltration capacity causing runoff and soil erosion), poverty / wealth (Alternative and more profitable labour sources are a permanent risk of land abandonment that can lead to degradation.)

Secondary causes of degradation: Heavy / extreme rainfall (intensity/amounts) (High intensity erosive rainfall is common), droughts (Dry periods and dry years require higher water availability)

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:

• prévenir la dégradation des terres
• réduire la dégradation des terres

Commentaires:

Main goals: prevention of land degradation, mitigation / reduction of land degradation

4.1 Dessin technique de la Technologie

4.3 Activités de mise en place/ d'établissement

	Activité	Calendrier des activités (saisonnier)
1.	Purchase of per (to cut pruning residue)

4.4 Coûts et intrants nécessaires à la mise en place

	Spécifiez les intrants	Unité	Quantité	Coûts par unité	Coût total par intrant	% du coût supporté par les exploitants des terres
Equipements	Per (to cut pruning residue)	piece	1,0	4761,0	4761,0	100,0
Coût total de mise en place de la Technologie					4761,0
Coût total de mise en place de la Technologie en dollars américains (USD)					4761,0

Commentaires:

Duration of establishment phase: 12 month(s)
Life span of the per: 10 years. Number of parties sharing: 2

4.5 Activités d'entretien/ récurrentes

	Activité	Calendrier/ fréquence
1.	Cut alpha-grass (optional)	winter
2.	apply mulch of alpha-grass, almond and pine tree pruning residue	early spring or autumn after almond pruning

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

	Spécifiez les intrants	Unité	Quantité	Coûts par unité	Coût total par intrant	% du coût supporté par les exploitants des terres
Main d'œuvre	Cut alpha-grass (optional)	person/days	4,0	95,25	381,0	100,0
Main d'œuvre	apply mulch of alpha-grass, almond and pine tree pruning residue	person/days	4,0	10,0	40,0	100,0
Equipements	Machine use	person/days	0,5	88,0	44,0	100,0
Engrais et biocides	Mulch	tons/ha	15,0	55,53333	833,0	100,0
Coût total d'entretien de la Technologie					1298,0
Coût total d'entretien de la Technologie en dollars américains (USD)					1298,0

Commentaires:

Machinery/ tools: Tractor and chopper to chop the almond pruning residue.

The original price of the chopper is estimated at $4761. In calculations it is assumed that the chopper is shared between at least two farmers, and with an average farm size of 10 ha, which gives a price of $238/ha establishment costs. Calculations include the cutting of alpha-grass to apply this as mulch in addition to the chopped almond and pine tree residue. Excluding the alpha-grass as a mulch reduces the total maintenance cost to 650. Leaving out also the chopped pine tree residue and using only the chopped almond pruning residue reduces maintenance costs to $44. The costs were indicated assuming a distance of 7 meter between almond trees and a mulch cover around each tree of 3*3 meters. Prices are for spring 2008.

4.7 Facteurs les plus importants affectant les coûts

Décrivez les facteurs les plus importants affectant les coûts :

Labour for cutting alpha grass, and the price of the mulch are most determining factors of the costs. Almond prunings are free of charge (except for costs to chop them), but will not provide enough mulch. Chopped Pine pruning or straw mulch are relatively expensive.

5.1 Climat

5.2 Topographie

5.3 Sols

5.4 Disponibilité et qualité de l'eau

5.5 Biodiversité

5.6 Caractéristiques des exploitants des terres appliquant la Technologie

Indiquez toute autre caractéristique pertinente des exploitants des terres:

Land users applying the Technology are mainly common / average land users

Difference in the involvement of women and men: Traditionally most agriculture is done by men in this region.

Population density: 10-50 persons/km2

Annual population growth: < 0.5%

15% of the land users are rich and own 20% of the land.
80% of the land users are average wealthy and own 75% of the land.
5% of the land users are poor and own 5% of the land.

Off-farm income specification: There is no difference in the ones who apply the technology and those who don’t. Most farmers do have an off-farm income for example from hunting, work in a factory, or office.

5.7 Superficie moyenne des terres utilisées par les exploitants des terres appliquant la Technologie

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

Propriété foncière:

• état
• individu, avec titre de propriété

Droits d’utilisation des terres:

• communautaire (organisé)
• individuel

Droits d’utilisation de l’eau:

• communautaire (organisé)
• individuel

Commentaires:

Most land is privately owned. Some shrubland or forest is state property. Water use is organised by permits to water extraction from aquifers on individual basis. Water rights are provided and controlled by the Water authority of the Segura river basin (CHS).

5.9 Accès aux services et aux infrastructures

6.1 Impacts sur site que la Technologie a montrés

Impacts socio-économiques

Production

Disponibilité et qualité de l'eau

Revenus et coûts

Impacts socioculturels

Impacts écologiques

Cycle de l'eau/ ruissellement

Sols

Biodiversité: végétale, animale

Réduction des risques de catastrophe et des risques climatiques

6.2 Impacts hors site que la Technologie a montrés

6.3 Exposition et sensibilité de la Technologie aux changements progressifs et aux évènements extrêmes/catastrophes liés au climat (telles que perçues par les exploitants des terres)

Changements climatiques progressifs

Changements climatiques progressifs

	Saison	Augmentation ou diminution	Comment la Technologie fait-elle face à cela?
températures annuelles		augmente	bien

Extrêmes climatiques (catastrophes)

Catastrophes météorologiques

	Comment la Technologie fait-elle face à cela?
pluie torrentielle locale	bien
tempête de vent locale	bien

Catastrophes climatiques

	Comment la Technologie fait-elle face à cela?
sécheresse	bien

Catastrophes hydrologiques

	Comment la Technologie fait-elle face à cela?
inondation générale (rivière)	pas bien

Autres conséquences liées au climat

Autres conséquences liées au climat

	Comment la Technologie fait-elle face à cela?
réduction de la période de croissance	bien

6.4 Analyse coûts-bénéfices

Quels sont les bénéfices comparativement aux coûts de mise en place (du point de vue des exploitants des terres)?

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

Commentaires:

Mulch is relatively expensive and so implies an additional cost.

6.5 Adoption de la Technologie

Commentaires:

There is no trend towards spontaneous adoption of the Technology

Comments on adoption trend: There is not so much awareness, and most farmers are afraid of possible costs of mulching and don’t count on increased crop yield.

6.7 Points forts/ avantages/ possibilités de la Technologie

Points forts/ avantages/ possibilités du point de vue de l'exploitant des terres
A good surface cover throughout the year provides good protection against erosion and helps reducing number of tillage operations and expenses How can they be sustained / enhanced? no suggestions

Points forts/ avantages/ possibilités du point de vue du compilateur ou d'une autre personne ressource clé
The main advantage is that a good surface cover is obtained below almonds that traditionally are characterised by a very poor surface cover during the whole year. The mulch will reduce evaporation and prevent erosion to take place. How can they be sustained / enhanced? Cheapest type of mulch should be identified (alpha grass, chopped pruning residues, …).

6.8 Faiblesses/ inconvénients/ risques de la Technologie et moyens de les surmonter

Faiblesses/ inconvénients/ risques du point de vue de l’exploitant des terres	Comment peuvent-ils être surmontés?
The price of the mulch	Look for alternative low cost materials

Faiblesses/ inconvénients/ risques du point de vue du compilateur ou d'une autre personne ressource clé	Comment peuvent-ils être surmontés?
The price of the mulch and/or the price of carrying it to the field	Look for alternative low cost materials, the nearest to the plots as possible.
Once the mulch in situ, any tillage operation would incorporate it to the soil, reducing part of its initial benefit; if the mulch is green (alpha grass) it would depress soil N levels upon decomposition, though it would increase SOM in the medium-long term	Avoid tillage in mulched areas

7.1 Méthodes/ sources d'information

7.2 Références des publications disponibles

Titre, auteur, année, ISBN:

Smets, T., Poesen, J. and Knapen, A., 2008. Spatial scale effects on the effectiveness of organic mulches in reducing soil erosion by water. Earth-Science Reviews, 89(1-2): 1-12.

Disponible à partir d'où? Coût?

Internet

Titre, auteur, année, ISBN:

Verdu and Mas 2007. Mulching as an alternative technique for weed management in mandarin orchard tree rows. AGRONOMY FOR SUSTAINABLE DEVELOPMENT. 27(4): 367-375

Disponible à partir d'où? Coût?

Internet

Titre, auteur, année, ISBN:

http://www.isahispana.com/

Disponible à partir d'où? Coût?

Internet

Titre, auteur, année, ISBN:

Mellouli, H.J., van Wesemael, B., Poesen, J. and Hartmann, R., 2000. Evaporation losses from bare soils as influenced by cultivation techniques in semi-arid regions. Agricultural Water Management, 42(3): 355-369.

Disponible à partir d'où? Coût?

Internet