Indigenous Trees as Hedgerows Species on Sloping Acid Upland 

Agroforestry System

Agustin R. Mercado, Jr., PhDDon Immanuel A. Edralin

World Agroforestry Centre (ICRAF)

Outline of presentation

• Upland areas and Smallholder 

• Hedgerow system development

• Agroforestry complementarity

• Indigenous tree species integrated on‐farm

• Promising vegetables grown with trees

Upland areas and Smallholder’sPhilippines• More than 7,000 islands• Population is 92 M people• Land area is 30 M has.• 10 M has sloping acid upland soils• 5 M has are less productive upland

areas due to degradation

A typical farm and farming household in the Philippine uplands: Poor, isolated, disenfranchised, and vulnerable but their actions on farm have impacts locally and beyond their farm boundaries. 

Claveria represents the bio‐physical and socio‐economic environments (>20M people; 30% of Philippines’ land area)

Upland areas and Smallholder’sProblem and solution

•Practices slash and burn system•Occupies about 1-2 has and •Subsistence farming practices•Choice of incorporating trees depends on their perceived influences to crops•Effective sector in restoring forest ecosystems or driving towards near forest ecosystems•Inappropriate farming practices• Soils are acidic and inherently poor•Declining productivity• Deforestation in upper watersheds• Poverty and malnutrition

• Communities in many forest and vegetable producing watersheds in the Philippines are suffering from forest, soil and water resources degradation, and poverty

• Trees should:– not compromise food production and the livelihood of upland farmers. It should instead complement income generation and  promote food security of farmers

– when integrated with vegetable production promote positive interaction, increased productivity, economic profitability, improve fertilizer use efficiency and enhance ecosystem functions

Upland areas and Smallholder’s• Soil loss ha‐1 yr‐1

– Traditional farming = 350 Mg

or 14,000 bags of soil

– Contour farming = 40 Mg

or 1,600 bags of soil

– Tolerable soil loss = 12 Mg

or 480 bags of soil

AgroforestryA land use system in which woody perennials (trees, shrubs, palms, bamboos)

are deliberately used in the same land management unit as agricultural crops (woody or not), animals or both, either in some form of spatial arrangement or temporal sequence – Lungren and Raintree (1982)

‐ Domestication of indigenous trees within AF may reduce pressures on natural forests

‐ Cannot really be as biodiverse as forests but can be better than convensional agric’l system

Hedgerow intercropping or alleycropping system1970-1990:

Pruned hedgerow1990-2000: NVS 2000- present:

commercial trees for fruit and

timber

PositiveControl soil erosionProvide organic fertilizerFodder for animalNegativeLabor intensiveCompetes with crops:space and growth resources

PositiveVery cheap to establishControl soil erosion effectivelyNegativeNo economic benefits

Potentials:Productivity/ProfitabilitySustainabilityEnvironmental services:

- Diversity- Carbon stocks

Upland areas and Smallholder’s

– Tree hedgrow system = 6.5 Mg

or 260 bags of soil

– Tolerable soil loss = 12 Mg

or 480 bags of soil

– Grass hedgerow system = 2.2 Mgor 88 sacks of soil

Upland areas and Smallholder’s

Effect of different hedgerow types on soil loss

===============================Hedgerow systems Soil loss (Mg ha‐1)‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Grasses  2.20 cForage legumes 9.80 cShrubs 5.70 cTrees 6.50 cContour cultivation 40.0 bTraditional cultivation 350.0 a

(up & down the slope)

Tolerable rate 12.0=============================================Rainfall: 3000 mm annually 

“The greatest immediate impact of timber hedgerow system is reduction of soil loss which is about 55 times than traditional up and down the slope cultivation thus making soil nutrients particularly N become available to the food crops”.

Understanding agroforestry biophysical processes leads to greater economic returns: Enhancing landscapes functions, livelihood

opportunities and sustainability

Tree‐vegetable interaction

Agroforestry system

4 Ways of Improving Economic Benefit of Agroforestry System

1. Increase the value of trees (T)

2. Increase the value of complementarity (Y2)

3. Decrease or eliminate competition value (Y1)

4. Decrease or eliminate the value of crop displacement area (D)

Increasing the value of T (Trees) (1)

• Choose indigenous timber trees with premium timber quality 

• Optimize vertical use of aboveground resources (space and light) by using multi‐canopies hedgerow systems (e.g. trees + banana + grasses)

• Optimize use of vertical and horizontal belowground  resources (space, water and nutrients) by using deep rooted indigenous trees)

• Optimize use of inert resources such as air and CO2 by using N2‐fixing trees (e.g. Narra Pterocarpus indicus and fast growing trees e.g lauan for timber and carbon sequestration)

Increasing the value of Y2 (2) (complementarity

zone) through the use of:

• Optimum tree line/

hedge spacing

• Responsive alley crops to 

micro‐climate improvement

• Deep‐rooted hedgerow species

• Optimum tree pruning regime (silviculture)

• Appropriate tree species or other hedgerow species (less competitive)

Decreasing the value of Y1 (3) (competition zone) through the use of:

• Adapted alleycrops (cassava vs maize)• Appropriate tree species 

– Medium to narrow and light canopies– Deep rooted – N2‐fixing (if possible)– Appropriate tree pruning regime

• Appropriate tree pruning regime (canopy removal and timing)• Supplemental water and nutrient application at competition 

zone (e.g. skewing the application of prunnings and fertilizer, application of drip irrigation)

• Orient the tree rows parallel to the direction of the sun (east‐west if possible)

Decreasing or  eliminating the value of D (crop displacement area) (4)

• Ensure that the value of T is greater than opportunity cost of D• Use similar approach as employed in increasing the value of T• Use of early maturing hedges in combination with indigenous 

trees (clonally propagated trees: rubber, coffee, timber and fruit trees (marcotting vs grafting; use of rooting hormones (IBA, ANAA, etc); forage grasses and legumes

• Reduce the displacement area by having fewer hedges (e.g. 20 meters instead of 5‐6 meters apart) thus enhancing AF complementarity effect

Indigenous trees on farm

kalumpit

molave

saplungan

lauan

apitong

tindalo

Indigenous tree species used as hedge

Local Name Scientific Name Family

Almon Shorea almon Dipterocarpaceae

Apitong Dipterocarpus grandiflorus Dipterocarpaceae

Dao Dracontomelon dao Anacardiaceae

Kalumpit Terminalia microcarpa Combretaceae

Molave Vitex parviflora Verbenaceae

Narra Pterocarpus indicus Fabaceae

Tindalo Afzelia rhomboidea Fabaceae

White lauan Shorea contorta Dipterocarpaceae

Yakal-saplungan Hopea plagata Dipterocarpaceae

Indigenous trees on farm

Indigenous trees on farm

0

10

20

30

40

50

60

70

80

90

100

Lower elevation Middle elevation Higher elevation

Percen

tage

Indigenous tree species

Harvested (%)

Mortality (%)

Survival (%)

Indigenous trees on farm

0

10

20

30

40

50

60

70

80

90

100

Lower elevations (457‐476 masl)

Middle elevation (519‐529 masl) Higher elevation (788‐953 masl)

Percen

tage

Indigenous tree species

1‐10 cm 

10‐20 cm 

20‐30 cm

30‐40 cm 

Diameter class

Performance assessment of tree, leafy, vegetables, fruit, root and climbing  vegetables 

Tree‐vegetable interaction

Growth of vegetables under trees

0

5

10

15

20

0 5 10 15 20

Bea

ns (g

/plt)

Distance from the tree

Competition zone Complementarity zone Nuetral zone Average yield 

Yield is less than Without trees

Yield is greater than without trees

Yield same as without trees

Schematic diagram of  tree‐vegetable agroforestry farm

D

Tree‐ tomato interaction under boundary planting system

Yield same as without trees

Yield is greater than without trees

Yield is less than Without trees

ComplementarityCompetition Neutral

Relationship between tree height (m) and net complementarity

y = 0.3034x + 12.696R2 = 0.14

0

2

4

6

8

10

12

14

16

18

20

(10.00) (5.00) - 5.00 10.00

Net complementarity

Tree

hei

ght (

m)

Relationship between canopy width and net complementarity

y = -14.254x + 560.37R2 = 0.08

0

100

200

300

400

500

600

700

800

900

(10.00) (5.00) - 5.00 10.00

Net complementarity

Can

opy

wid

th (c

m)

Promising vegetables at competition zone (4.5 (±1.2)m from tree hedge)

Type Species Scientific name VarietyLeafy Amaranthus (5) Amaranthus caudatus TOT 2272 0.80 a

Jute (4) Corchorus olitorius TOT 4721 0.53 cCabbage Brassica oleracea Resest crown 0.73 abChinese cabbage Brassica rapa Blues 0.63 b

Fruit Eggplant (3) Solanum melongena S00- 633 0.67 b

Bellpepper Capsicum annuum 9950-5197 0.80 aOkra Abelmoschos esculentus 0.60 bTomato Lycopersicon esculentum WVCT-1 0.73 ab

Climbing Alugbati (3) Basella alba TOT 5274 0.73 ab

Yardlong bean (3) Vigna unguiculata TVO 2074 0.40 dTree (4) Malunggay Moringa oleifera local 0.57 bc

Chinese malunggay Sauropus androgynous local 0.80 aRoot Carrots Daucus carota local 0.80 a

In a column, means having a common letters are not significantly different by

by Tukey's test at 5% level

Adaptability index

Adaptability index = Yield at competition zone (Y1)  / yield at neutral zone (Y0)

Where: 1= adapted

Promising vegetables at complementarity zone(from 5 – 15 (±2) m from tree hedge)

Type Species Scientific name VarietyComplementarity

indexLeafy Amaranthus (5) Amaranthus caudatus TOT 2272 Taiwan 2.10

Jute (4) Corchorus olitorius TOT 6667 2.70Cabbage Brassica oleracea Resest crown 1.33Chinese cabbage Brassica rapa Blues 1.60

Fruit Eggplant (3) Solanum melongena S00- 633 1.50Bellpepper Capsicum annuum 9950-5197 1.57Okra Abelmoschos esculentus 1.57Tomato Lycopersicon esculentum WVCT-1 1.33

Climbing Alugbati (3) Basella alba TOT 5274 1.87Yardlong bean (3) Vigna unguiculata TVO 2141 Philippines 2.27

Tree Malunggay (4) Moringa oleifera local 1.43Chinese malunggay Sauropus androgynous local 1.17Katuray Sesbania grandiflora local 3.37

Root Carrots Daucus carota local 1.57

Complementarity index = Yield at complementarity (Y2)  / yield at neutral zone (Y0)

Where: 1= no complementarity effect

Percent increase of crops at complementarity zones

Vegetables Wet season(June – Sept)

Dry season(Feb – May) Average

Chinese cabbage 37 30 34

Cabbage 13 0 7

Tomato 40 10 25

Bell pepper 20 10 15

Carrots 37 30 34

Mean 29 16 18

Conclusion• Indigenous  trees e.g. Lauan performed well with agric. crops hence can be use to improve the value of T to have higher net benefit or complementarity

• Inclusion of indigenous trees on farm reduces the amount of soil erosion and thereby reducing fertilizer replacement cost making the system an advantage to smallholder farmers 

• Indigenous trees increase above ground and fertilizer use efficiency by taking up leached nutrients below crop root zone

Conclusion• Amaranthus, cabbage, bellpepper,  tomato, alugbati, chinese malunggay and carrots are adapted to the 1‐4.5m +/‐ 1.2m from tree lines hence may produce well under competition zones 

• Amaranthus, jute, chinese cabbage, bellpepper, okra, yardlong bean and katuray planted under trees attained above average yield than w/o trees thus may produce more when planted at complementarity zones 

Conclusion

• The use of indigenous tree species, like Molave, Saplongan, Lauan,  in agroforestry is a viable option for smallholders to increase upland farming systems total productivity and climate change resilience

• The added value of using indigenous trees in agroforestry apart from having premium timber price is they act as biodiversity corridors linking patches of forests for habitat linkage and solving forest fragmentation

Conclusion

• Incorporating timber trees on farm is economically viable as it enhances agricultural production promoting short‐term and medium‐term and long‐term requirements and promotes soil and water conservation

End of presentation