Upload
coby-esterbrook
View
220
Download
3
Tags:
Embed Size (px)
Citation preview
Sustainable Agroforestry in Degraded Drylands:
Win – Win Approaches for Local, Regional and Global Problems
Leu S. and Mor-Mussery A.
in collaboration with the Sustainability Laboratory
Overexploitation Land Degradation by
-Productivity
-Carbon Stocks
-Biodiversity-Resilience and Sustainability Mismanagement
Acceleration of and Sensitization to Effects of Global Warming
2. Rehabilitation by Restoration of Vegetation
Productivity+
Carbon Stocks+
Biodiversity+ Resilience and Sustainability+ Management
Mitigation of and Adaptation to Effects of Global Warming!
Engineering or Forestry
Topography Analysis and Engineering RequirementsN
Site plan
Riverine, native plants
*Plants the will be suited in the edges of the river
Silvipasture
Savanna trees with additional uses (mainly pasture), suited to arid zones,
Shade trees
The shade pathways
Fenced Green Tree
To border between the different fields and supplement extra use (crop, pasture, shade
etc…)
• The area excluded by the black line is unsuitable for large agricultural plots, while areas 1 – 4 do not pose any problems except for small corrections along the river;
• The following pictures demonstrate these facts;
200m
Only the two marked rhomboids are suitable for agriculture, about 10 and 5 dunam;
Stable Wadi
Unstable Wadi
and Soil
Large Rocky Slope with Wadis
The Soil in the southern-most Wadi is highly erosive; these erosion structures have to be stabilized by terraces, planting of
mixed trees, olive plantations and high value trees; Native trees will be incorporated for high grazing value, biodiversity and
agricultural return;
Technique1: Restoration of vegetation, erosion control and tree planting using contour drip irrigation
Trees and Shrubs were planted along drip irrigation, every 2m one line was established, and every dripper received 100L of water
during November-December 2008.
The number of functions fulfilled by dryland trees is huge• Carbon Sequestration into biomass;
• Recovery of nutrients from deep soil;
• Enrichment and protection of top soils by plant litter;
• Increasing productivity of annual vegetation;
• Preventing wind erosion;
• Providing shade to animals and buildings;
• Preventing water runoff and erosion;
• Restoring natural habitats and biodiversity;
• Providing fodder during the dry season;
• Providing biomass energy;
• Providing high value oils and fruit for economic expansion;
Technique2: Restoration of land using dryland trees
20 years old Acacia victoria woodland near Yattir farm (220 mm
mean Annual Precipitation)
2.5 t per ha and year annual vegetation;2.5 tons per ha and year tree litter (edible);1 ton per ha and year woody biomass;6 tons per year CO2 sequestration;Supports 2 goats per ha:
RICH ANIMAL LIFE
Degraded land nearby:
0.5 t per ha and year annual vegetationNO tree litter!NO woody biomass!NO CO2 sequestration!Supports 0.2 goats per ha
NEGLIGIBLE ANIMAL LIFE!!!
*Problem: Acacia victoria is not a native species!
Fact: Woodland trees Sequestrate high Carbon amounts into biomass
Biomass, slope trees
0
5
10
15
20
25
30
35
40
45
Total Litter Weeds
g p
er
600cm
^2
canopy
open
Facts: Grazing Improvement, Land Rehabilitation and Biomass Production by Silvipasture
Biomass and Litter under Tree Canopy and in nearby Open Areas:
Suitable Trees Promote Growth of Annual Vegetation and Provide Extraordinary Amounts of Organic Litter!
Facts: Using trees for agriculture purposes in arid environments
Left: niche of wheat growing without need of irrigation and nutrient supply;
Right: Small olive tree survives inside the Acacia victoria woodland, taking advantage of higher soil fertility and humidity, reduced
evaporation and protection from wind by the other trees .
planting techniques: The planting method dramatically affects soil characteristics
Contour Trenching Planting without Soil Disturbance
0
0.5
1
1.5
2
2.5
3
Savanna Open Contour Open Savanna Canopy Contour Canopy
SO
C (
%)
Terrace Agroforestry using Natural Topography
A simple stone terrace suffices to create excellent conditions for Olive cultivation. The reduced water runoff intensity allows natural vegetation to recover as well.
Intercropping in Agroforestry Terraces
Other Crops Used for Intercropping:
• Vegetables• Watermelons• Sunflowers• Tobacco
Classical agroforestry with summer sorghum (left behind) intercropped with olive trees. The humidity stored in the soil of the dammed areas suffices to maintain growth of sorghum throughout the hot, completely dry summer.
An area covered by manure (right) displayed very significant plant growth in spite of very poor rainfall (~110 mm in 2009), in contrast to the
exposed soil to the left.
Principle of Soil Management:THE MOST IMPORTANT:Exposed Soil Degradation
Expected Benefits at Wadi Attir
• Carbon sequestration compensating for the agricultural greenhouse gas emissions.
• Water savings by optimized agricultural production, wind breaks, plant litter and no till agriculture;
• Reduced fertilizer use due to nitrogen fixing plants and nutrient recovery from deep soil by trees;
• Improved biodiversity due to planted native trees;• Increased profitability due to growing amounts of
high quality high price oils;• Providing waste biomass for energy production from
tree trimming; • Reduced erosion and soil loss due to terrace
agroforestry and erosion barriers;