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

Nom du projet qui a facilité la documentation/ l'évaluation de la Technologie (si pertinent)

The Future of Okavango (TFO / GLUES)

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

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

01/03/2001

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

Oui

1.4 Déclaration sur la durabilité de la Technologie décrite

Est-ce que la Technologie décrite ici pose problème par rapport à la dégradation des terres, de telle sorte qu'elle ne peut pas être déclarée comme étant une technologie de gestion durable des terres?

Non

2.1 Courte description de la Technologie

Définition de la Technologie:

Conservation agriculture using permanent water-harvesting planting basins, or rip-lines and fertilizer/manure application on low fertility dryland soils.

2.2 Description détaillée de la Technologie

Description:

Farmers in north-eastern Namibia practice shifting/semi-permanent subsistence cropping, concentrating on pearl millet cultivation. Here, conservation agriculture (CA) was promoted to sustain and improve production and to reduce conversion of woodland to crops. CA comprises the three principles of minimum soil disturbance, permanent soil cover, and rotation. CA was tested on small plots with volunteers trained by a local NGO. The technology was characterized here by: (i) Early (pre-rains) preparation of the land with two alternative techniques; either: a) basins with a defined spacing opened by a hand hoe, with composted manure added (biochar has also been tested), or b) rip-lines prepared with oxen in lines and with manure application within the rip lines; (ii) Mulching the soil with crop residues, branches or sunnhemp, specially grown for the purpose; (iii) Protection against grazing of crop and mulch by livestock; (iv) Intercropping with vegetables or legumes. (v) Weeding.

CA has been promoted for four seasons, and now trained farmers are transferring their knowledge to others. The technology was promoted to substantially improve the low yields of traditionally practiced agriculture by improving fertility and soil structure as well as better capturing runoff. It was also aimed at avoiding further expansion of croplands into dry woodlands on low fertility arenosols. Eventually it is hoped that the well-being of local subsistence cropping communities will be improved and outmigration reduced.

Knowledge about CA comes from Zambia, where it has been has been practiced successfully for many years by small-scale farmers. A local NGO was engaged by an international project (www.future-okavango.org) which searched for volunteer farmers in the Kavango area. The first CA planting took place in 2011/12. These pioneer farmers were backstopped regularly and the number of farmers trained increased. The NGO monitored crops with contact farmers. 45 more farmers showed interest and were then trained by the contact farmers. Training and backstopping continued until August 2015.

The natural environment is semi-arid. Rainfall is concentrated from November to March. Mean annual precipitation is 570 mm, and mean air temperature is 26.2°C in the hottest month (October) and 16.2°C in the coldest month (July). The landscape forms part of the extended Kalahari basin in central-southern Africa. Deep and extended sands restrict people to living in areas close to surface water. Villages are located along the Okavango on the elevated river terraces – where they produce crops. Here, sedimentation of fine-grained soils, the accumulation of calcium carbonates in the subsoil and the activity of termites have resulted in soils of medium fertility which could potentially ensure yields of 500 kg/ha of millet, if well managed, and assuming good rainfall. Due to the growing population and restricted land availability, cultivation patterns have changed from shifting to semi-permanent and expanded to the adjacent woodlands on the deep Kalahari sands. Here, rapid degradation of soil fertility has caused further expansion and reduced crop yields to very low levels (ca. 150 kg/ha on average). Livestock graze and browse vegetation on the floodplains and in the woodlands. Due to night-time kraaling of livestock, manure is available as fertilizer: thus sustained cropping can be supported. The importance of the woodlands for ecosystem services including timber and firewood, for thatching grass, medicinal plants and biodiversity means they must be conserved and this acts as a reason to support the search for alternative crop production systems such as CA.

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 moins de 10 ans (récemment)

2.7 Introduction de la Technologie

Spécifiez comment la Technologie a été introduite: :

• par le biais de projets/ d'interventions extérieures

Commentaires (type de projet, etc.) :

Introduction in the area by Community Economic Development Programme (CEDP) TFO-project in 2011

3.1 Principal(aux) objectif(s) de la Technologie

• améliorer la production
• réduire, prévenir, restaurer les terres dégradées
• préserver l'écosystème

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

Commentaires:

Major land use problems (compiler’s opinion): Low and very variable yields per ha; ongoing expansion of fields to less fertile woodlands due to nutrient depletion of originally fertile plots; years with dry spells
Major land use problems (land users’ perception): Crop wilting and poor yields, opening new areas in search of better fields, cutting down trees, slushing and burning residues
Type of cropping system and major crops comments: Under CA, sunhemp for residue and nitrogen fixing has been grown as green manure and fodder for livestock.

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: 135, Longest growing period from month to month: Nov to March

Densité d'élevage/ chargement (si pertinent):

1-10 LU /km2

3.4 Groupe de GDT auquel appartient la Technologie

• gestion intégrée de la fertilité des sols
• mesures en travers de la pente
• récupération/ collecte de l'eau

3.5 Diffusion de la Technologie

Spécifiez la diffusion de la Technologie:

• répartie uniformément sur une zone

Si la Technologie est uniformément répartie sur une zone, indiquez la superficie couverte approximative:

• < 0,1 km2 (10 ha)

Commentaires:

SLM technology was applied by trained smallholders on small plots

3.6 Mesures de GDT constituant la Technologie

Commentaires:

Type of agronomic measures: early planting, mixed cropping / intercropping, mulching, green manure, legume inter-planting, manure / compost / residues, rotations / fallows, minimum tillage, pits

3.7 Principaux types de dégradation des terres traités par la Technologie

Commentaires:

Main causes of degradation: soil management (Missing nutrient returns)
Secondary causes of degradation: over-exploitation of vegetation for domestic use (Grazing and burning of crop residues), population pressure (Expansion of croplands to less fertile soils)

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:

• restaurer/ réhabiliter des terres sévèrement dégradées

4.1 Dessin technique de la Technologie

4.2 Spécification/ explications techniques du dessin technique

Scheme of CA field with basins
Within the fenced area, basins are dug per hand-hoe in lines with about 15 cm width, 35 cm length and 15 cm depth and in 70 cm distance. To keep the line and position, a rope with knots every 70 cm is used. Each basin is refilled with 2 cans of manure mixed with part of the soil material. Maize or pearl millet - two stages shown on the graph
Location: Mashare. Kavano East/Namibia

Technical knowledge required for field staff / advisors: moderate
Technical knowledge required for land users: low
Main technical functions: increase in nutrient availability (supply, recycling,…)
Secondary technical functions: increase / maintain water stored in soil, increase of biomass (quantity)

Early planting
Remarks: Planting basins prepared in dry season, planting can occur by first rainfalls (earlier than plough-d

Mixed cropping / intercropping
Material/ species: Maize / Millet /Cowpea
Remarks: Cultivated in parallel lines

Mulching
Material/ species: Grasses & crop residues & sunhemp
Remarks: sunhemp cultivated on the CA field and cut to produce mulch

Green manure
Material/ species: branches of fertilizer tree

Manure / compost / residues
Material/ species: Composted manure from cattle post

Rotations / fallows
Material/ species: Maize / Millet /Cowpea
Remarks: Planted in lines and shifted annually

Minimum tillage
Material/ species: Riplines by oxen

Pits
Material/ species: planting basins by hand hoe

Retention/infiltration ditch/pit, sediment/sand trap
Spacing between structures (m): 0.7
Depth of ditches/pits/dams (m): 0.15
Width of ditches/pits/dams (m): 0.15
Length of ditches/pits/dams (m): 0.35

Structural measure: ripline
Spacing between structures (m): 0.7
Depth of ditches/pits/dams (m): 0.25
Width of ditches/pits/dams (m): 0.1

For water harvesting: the ratio between the area where the harvested water is applied and the total area from which water is collected is: 1:8,3
Change of land use practices / intensity level: More specific soil management; crop protection by fencing; earlier seeding
Major change in timing of activities: To a large part, land preparation can be carried out throughout dry season, independent of rainfall level

4.3 Informations générales sur le calcul des intrants et des coûts

autre/ monnaie nationale (précisez):

Nam $

Indiquer le taux de change du dollars en monnaie locale (si pertinent): 1 USD= :

15,5

4.4 Activités de mise en place/ d'établissement

	Activité	Type de mesures	Calendrier
1.		Modes de gestion	dry season

4.5 Coûts et intrants nécessaires à la mise en place

	Spécifiez les intrants	Unité	Quantité	Coûts par unité	Coût total par intrant	% des coût supporté par les exploitants des terres
Main d'œuvre	labour	ha	1,0	1104,0	1104,0	100,0
Matériaux de construction	Wire for fencing	ha	1,0	224,0	224,0	100,0
Matériaux de construction	sticks & poles	ha	1,0	1114,0	1114,0	100,0
Coût total de mise en place de la Technologie					2442,0

Commentaires:

Duration of establishment phase: 3 month(s)

4.6 Activités d'entretien/ récurrentes

	Activité	Type de mesures	Calendrier/ fréquence
1.	Repairing fences and de-bushing of the fields	Agronomique	(May - July)
2.	Gatering and spreading of mulch cover	Agronomique	July - Dec
3.	Cutting sunhemp and applying as additional mulch	Agronomique	Feb-Mar
4.	Re-digging the planting basins	Agronomique	August
5.	Manure collection, Planting & fertilizer application	Agronomique	September - December
6.	Sowing of main crops and sunnhemp and fertilizer application	Agronomique	November - December
7.	Intercropping with legumes like groundnuts and cowpeas normally two weeks after germination of cereals.	Agronomique
8.	Weeding	Agronomique
9.	Harvesting	Agronomique	April - May

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

	Spécifiez les intrants	Unité	Quantité	Coûts par unité	Coût total par intrant	% des coût supporté par les exploitants des terres
Main d'œuvre	labour	ha	1,0	848,0	848,0	100,0
Matériel végétal	seeds	ha	1,0	22,0	22,0	100,0
Engrais et biocides	fertilizer	ha	1,0	159,0	159,0	100,0
Engrais et biocides	compost/manure	ha	1,0	276,0	276,0	100,0
Matériaux de construction	Wire for fencing	ha	1,0	220,0	220,0	100,0
Coût total d'entretien de la Technologie					1525,0

Commentaires:

Machinery/ tools: Values above are for manual CA using a hoe; an external worker earns 4 N-$ per working hour; above, family labour was multiplied by 4 to estimate the “value” of the family labour invested
The costs are based on labour needs of one year and 500 kg/ha of fertilizer

4.8 Facteurs les plus importants affectant les coûts

Décrivez les facteurs les plus importants affectant les coûts :

CA was designed to require minimal financial investments; theoretically, everything apart from wire for the fences and inorganic fertilizer can be created or gather by the household. This turns CA into a very labour intensive farming practice. The high Dollar values above result from multiplying the (free) family labour invested in farming with the typical hourly wage rate of an external worker

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
Population density: 10-50 persons/km2
Annual population growth: 1% - 2% (One farmer to our knowledge could be considered wealthy). (Few average farmers). (Mostly CA farmers are poor).

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:

• état
• communauté/ village

Droits d’utilisation des terres:

• communautaire (organisé)

Droits d’utilisation de l’eau:

• communautaire (organisé)

Commentaires:

parallel existence of state and communal laws

5.9 Accès aux services et aux infrastructures

6.1 Impacts sur site que la Technologie a montrés

Impacts socio-économiques

Production

Revenus et coûts

Impacts socioculturels

Impacts écologiques

Cycle de l'eau/ ruissellement

Sols

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)

Extrêmes climatiques (catastrophes)

Catastrophes climatiques

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

Commentaires:

Dig basins at 20cm (0.20m) deep; and extra water harvesting basins at 0.45m in-between the rows. For the ox-ripped lines, use ripper wings to open a wider farrow for water harvesting

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)?

6.5 Adoption de la Technologie

Commentaires:

SLM Technology has been applied by own interest of smallholders
100% of land user families have adopted the Technology without any external material support
There is a strong trend towards spontaneous adoption of the Technology

6.7 Points forts/ avantages/ possibilités de la Technologie

Points forts/ avantages/ possibilités du point de vue de l'exploitant des terres
Saves labour over time
Can use less land compared to conventional system for the same harvest/yield

Points forts/ avantages/ possibilités du point de vue du compilateur ou d'une autre personne ressource clé
A strength of the system is the timely land preparation
The advantage of permanent planting stations results from the higher availability of nutrients to crop roots.
The moisture retention within the rooting space is improved by the surface structure and the increase in soil organic matter
The rotations of crop rotations is encouraged
All inputs can be used precicely, there is less wastage of inputs

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 weed management is labour intensive and the impact of pests might be a future challange.	The application of more mulch and the weeding regularly in the first part of the season is supposed to reduce weeds.

Faiblesses/ inconvénients/ risques du point de vue du compilateur ou d'une autre personne ressource clé	Comment peuvent-ils être surmontés?
To start with this technology is labour intensive at the beginning. In this moment, the hard pan caused by years of ploughing has to be loosened.	Because the basins/riplines are permanently maintained in CA, the preceding land preparations become easier. Also since land preparation starts before on-set of rains, one can spread labour by starting just after harvesting crop
There is a general problem of constructing fences around fields in communal lands, as state authorities declare this land as being owned by the state.	By agreeing with the local leadership to allow those doing CA to fence off their fields for proper keeping of residues and basins/riplines that might be prone to free livestock grazing after crop harvests.

7.1 Méthodes/ sources d'information

7.2 Références des publications disponibles

Titre, auteur, année, ISBN:

Groengroeft, A., et al. (2013) A method for yield assessment on rainfeld dryland agricultural fields.

Disponible à partir d'où? Coût?

Biodiversity & Ecology 5:279 - 286

Titre, auteur, année, ISBN:

Kowalski, B. et al. (2013) Mashare - The People.

Disponible à partir d'où? Coût?

Biodiversity & Ecology 5:121-128

Titre, auteur, année, ISBN:

Pröpper, M. et al. (2010) Causes and perspectives of land-cover change through expanding cultivation in Kavango.

Disponible à partir d'où? Coût?

Biodiversity in southern Africa. Volume 3: Implications for landuse and management, eds. M. T. Hoffman, U. Schmiedel and N. Jürgens. Göttingen & Windhoek: Klaus Hess Publishers.

Titre, auteur, année, ISBN:

Pröpper, M. et al. (2015) The Future Okavango – Findings, Scenarios and Recommendations for Action.

Disponible à partir d'où? Coût?

Research Project Final Synthesis Report 2010-2015, 190. Windhoek: University of Hamburg