Competition, land rehabilitation & research communication.

Gert Nyberg, Bekele Lemma, Zacharia Gnakambary, Jules Bayala, Edmundo Barrios, Henry Neufeldt, Bernard Vanlauwe,

Hugues Bazie, Mats Öqvist, John Nyaga, Aida Bergues Tobella

Decrease in communal grazing land

Decrease in inorganic fertilizer

use. Increasing fertilizer price & no

subside.

Decrease in cattle number

Decrease in manure

increased removal of crop residue for fodder and fuel

Decrease in soil fertility

Decrease in forest cover

Trees

Crops -Shade -Soil fertility

animals - Shade around homestead - Fodder (leaves & pods)

humans -Shade for resting and lunching -Farm equipments, fuel wood, construction material

Trees on farm lands

• households - have trees on their farms • Common trees – acacia, croton and cordia – kela -acacia and croton – dorebafana

• Distribution – scattered

• Grown naturally- remnant or regenerated

• Age –old and young trees

• Management – pollarding and pruning (dominant) – To collect fuel wood, construction material, … – To reduce shade to acceptable level – Done once in a year or in two year or in three year

• Benefits- crops cattle and humans

• Most households believe that on farm trees improve soil fertility – Very few think that trees are competitive with crops

• Almost all recognize soil fertility differences under canopy and

outside canopy – Evidences

• soil color (darker), soil moisture, appearance of crops (vigor, taller, color of leaves …)

– When applying fertilizers • 68 %, 52% (Kela, Dore) of households applied less

fertilizer under canopy – Reason crops grow faster and collapse when applied on the

same rate • 32 %, 48% (Kela, Dore) of the households claimed

uniform application, but better crop performance under canopy

0,000

20,000

40,000

60,000

80,000

100,000

120,000

0 1 2 3 4

resp rate/distance from trees

Eucalytptus

Markhamia

Sesbania

Sesbania in Napier

1

1,2

1,4

1,6

1,8

2

2,2

0 1 2 3 4 5

Eucalyptus

Markhamia

Sesbania

Sesbania in Napier

-21

-20

-19

-18

-17

-16

-150 1 2 3 4 5

Eucalyptus

Markhamia

Sesbania

Sesbania in Napier

y = -0,4071x - 14,606 R² = 0,8195

-19,000

-18,000

-17,000

-16,000

-15,000

-14,000

-13,000

-12,000

-11,000

-10,0000 1 2 3 4 5 6 7 8 9

y = 0,3392x - 19,974 R² = 0,9923

y = 0,3079x - 19,823 R² = 0,998

y = 0,3153x - 19,828 R² = 0,9964

y = 0,3067x - 19,221 R² = 0,9929

-19,000

-18,000

-17,000

-16,000

-15,000

-14,000

-13,000

-12,0005,000 6,000 7,000 8,000 9,000 10,000 11,000 12,000 13,000 14,000 15,000

dist 1 dist 2

dist 3 dist 4

y = 0,3601x - 19,785 R² = 0,9966

y = 0,4047x - 19,848 R² = 0,9741

y = 0,3822x - 19,817 R² = 0,9887

-18,500

-18,000

-17,500

-17,000

-16,500

-16,000

-15,500

-15,0004,000 5,000 6,000 7,000 8,000 9,000 10,000 11,000 12,000

dist 1

dist 2

dist 3

Gully rehab Gully reference

Woodlot at farmers field

Control

0

1

2

3

4

5

6

7

8

C C ratio2011

N N ratio2011

P 2009 ic 2009 ic 2011

Woodlots/reference ratio

0,0

10,0

20,0

30,0

40,0

50,0

60,0

woodlots 2009 control 2009 woodlots 2011 control 2011

mm

/h

b

a

c

b

bars with the same letter are not statistically different at p<0.05

Infiltrability four & six years after planting

Infiltration rates in land rehab sites 2009 & 2011

0

5

10

15

20

25

30

35

T C

2009

2011