1
CONTACT PERSON |
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1.1
Name |
Ms
Adelaide Moyo |
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1.2
Address |
Makoholi
Research Station
Agritex Contill Project,
Box 790, Masvingo, Zimbabwe |
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1.3
Tel |
+263
39 7006/63255 |
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1.4
Fax |
+263
39 64035 |
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1.5
E-mail |
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1.6
List other researchers involved: |
Messrs
Isaiah Nyagumbo and Martin Munyati. |
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2
WATER EROSION |
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2.1
mm2 - cm2: |
Dynamics
of soil aggregation |
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2.2
m2: |
soil
surface dynamics: physical degradation (surface sealing, crusting)
and its impact on surface roughness, infiltration and runoff:
influence of tillage (mulched, ridged, ripped or ploughed) on
run-off and infiltration; biological processes: the effect of
ground cover (crop, mulch and weed) on run-off and subsequent
soil loss. |
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2.6
Other scale or processes investigated: |
interrill
and rill erosion: sheet erosion is quantified on arable land
(cropped and bare plots). |
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3
WIND EROSION |
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4
MASS MOVEMENTS |
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5
TILLAGE EROSION |
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Tillage
erosion assessment on 300 m2 run-off plots. Five
tillage systems are being tested on their effect on erosion.
Can newly developed conservation tillage techniques reduce erosion
to tolerable levels? Conventional mould board ploughing serves
as the basis for comparison. |
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6
TEMPORAL SCALE OF EXPERIMENTS |
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6.1
events: |
Yes |
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6.2
days: |
Yes |
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6.3
weeks: |
Yes |
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6.4
months: - |
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6.5
years: |
Yes |
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6.6
remarks |
+
the experiment has been on-going since 1988/89 and 1996/97 might
be its final year. Validation of an already existing soil erosion
model (SLEMSA) will be done.
Met data
is collected daily. Run-off and soil loss quantification is
done on an event basis i.e. after every storm. Ground cover,
plant growth parameters and soil moisture measurements are
carried out weekly. Yield assessment and some soil analyses
are done annually.
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:
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7
DESCRIPTION OF EROSION FACTORS STUDIED |
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7.1
Climate: |
Daily
rainfall (quantity, intensity), evaporation. |
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7.2
Topography: |
Slopes
(length and steepness fixed). |
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7.3
Soils: |
Hydraulic
conductivity, water retention, bulk density, texture, organic
matter, aggregate stability, soil moisture and analysis of sediments. |
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7.4
Vegetation: |
None |
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7.5
Management: |
Maize
production suitable for small scale and communal farming, land
is tilled using ox-drawn implements. |
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7.6
Others: |
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8
FIELD EXPERIMENTS Description of the field site and
of the type of experiments and equipment involved for each of
the erosion processes being studied: |
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8.1
Erosion process: |
(1)
Quantification of soil loss and run-off from 300 m2
run-off plots. Treatments include one bare fallow and four tillage
systems. |
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8.2
Location (town, state, country): |
(1)
Makoholi Research Station, Masvingo, Zimbabwe.
(2) Domboshawa Training Centre, Harare, Zimbabwe. |
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8.3
Equipment involved: |
Sediment
tanks; spectrophotometer; double ring infiltrometer; neutron
probe weather station; crop cover frames. |
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8.4
Remarks: |
Neutron
probe and weather station currently out of order. |
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9
LABORATORY EXPERIMENTS Description of the laboratory
and the type of experiments and equipment involved for each
of the erosion processes studied: |
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- Soil
retention: pressure pots
- Hydraulic
conductivity: permeameter
- Aggregate
stability: wet sieving
- Bulk
density: ring
- Texture:
hydrometer
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10
REMARKS |
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During
three of the nine years (1993/94 to 1995/96) sediments have
not only been quantified but they also have been analysed for
N, P, K, Ca, Mg, organic matter, texture. The nutrients lost
as a result of erosion will be compared relative to nutrient
losses due to leaching and plant uptake.
Productivity
loss due to erosion is being quantified, where topsoil is
artificially removed from plots and yield assessed (scalping
depths of 0; 5; 10; 15 and 20 cm).
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11
LIST RELEVANT PUBLICATIONS |
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Moyo
A. and J. Hagmann, 1994. Growth-effective rainfall in
maize production under different tillage systems in semi-arid
conditions and shallow granitic sands of southern Zimbabwe.
In proceedings of 13th International Soil Tillage Research Organisation
Conference, Vol. 1, pp 475-480. Aalborg, Denmark.
Moyo,
A. 1996. The effect of soil erosion on soil productivity as
influenced by tillage: with special reference to clay and
organic matter losses. Paper presented at the ISCO Conference
in Bonn, August, 1996. (In press).
Moyo,
A. 1996. Summary results of the on-station results at Makoholi:
1988-1995. (Not yet published).
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