Bibliography: Land Degradation in South Africa project

bedekking op afloop, sedimentverliese en waterverbruiksdoeltreffendheid van

natuurlike veld. Journal of the Grassland Society of southern Africa 3(4):153-

158, 1986.

Reprint : In File,

Keywords : SOIL EROSION; RUNOFF; SEDIMENTATION; VELD CONDITION; GRAZING EFFECTS;

GRASSLAND; FREE STATE; PLANT PHYSIOLOGY

Ref ID : 361

1865. Snyman, H.A. and Van Rensburg, W.L.J. Effect of slope and plant cover on

run-off, soil loss and water use efficiency of natural veld. Journal of the

Grassland Society of southern Africa 3(4):153-158, 1986.

Reprint : In File,

Keywords : SOIL EROSION; VELD CONDITION; VELD MANAGEMENT; HYDROLOGY;

SEDIMENTATION; RUNOFF; VEGETATION DYNAMICS; RAINFALL

Abstract : Run-off and soil loss were monitored from a climax, subclimax and

pioneer veld, each on a 5,9%, 4,1% and 2,1% slope, by means of a rainfall

simulator on a Valsrivier soil form. With rainfall intensity, soil moisture

content at the beginning of each rain storm, and soil texture the same for each

treatment, plant cover and composition had a significant (positive) (P < 0,05)

influence on the amount of soil loss and run-off that occurred, as against the

insignificant influence of the slope. An average of 6,2 t/ha soil loss and

80,6% run-off of the amount of water applied occurred from the pioneer veld

(0,7% basal cover) on the steepest slope. In all the successional stages more

run-off and less soil loss occurred from wet soil than from dry soil.

Significant (P < 0,01) relationships between basal and canopy cover were

obtained with run-off and soil loss. The climax, subclimax and pioneer veld

produced on average 0,57 g, 0,23 g and 0,07 g aboveground phytomass for each

litre of water evapotranspirated.

Ref ID : 362

1866. Snyman, H.A. and Van Rensburg, W.L.J. Sedimentverlies en oppervlakafloop

vanaf natuurlike veld in die sentrale Oranje-Vrystaat/Soil loss and runoff from

natural veld in the central Orange Free State. Water SA 13(4):245-250, 1987.

Reprint : In File,

Keywords : SOIL EROSION; SEDIMENTATION; VELD CONDITION; VELD MANAGEMENT; FREE

STATE; RUNOFF; RAINFALL

Abstract : Soil loss and runoff from natural veld in the central Orange Free

State. A rotating-boom rainfall simulator is being used to measure soil losses

and runoff from natural veld in different successional stages at a 1,8% slope on

a Valsriver soil form. Plant cover and composition had a significant influence

on soil loss and runoff. Soil loss from the pioneer grass cover (0,7% basal

cover) was as much as 3,9 t/ha. No runoff was recorded from the climax grass

cover (7,1% basal cover).

Ref ID : 636

1867. Snyman, H.A. and Van Rensburg, W.L.J. Korttermyn invloed van strawwe

droogte op veldtoestand en waterverbruiksdoeltreffendheid van grasveld in die

sentrale Oranje-Vrystaat/Short-term effect of severe drought on veld condition

and water use efficiency of grassveld in the central Orange Free State. Journal

of the Grassland Society of southern Africa 7(4):249-256, 1990.

Reprint : In File,

Keywords : SOIL EROSION; DROUGHT; VELD CONDITION; GRASSLAND; FREE STATE

Abstract : The impact of an intensive drought (1982/83 and 1983/84 - growing

seasons) on botanical composition, basal cover, mortality of grazing plants and

water use efficiency (WUE) of veld in good, moderate and poor condition was

identified. Increaser II species were apparently more capable of surviving

drought than the Decreaser species. Under optimal soil moisture conditions the

Decreaser species increased and the Increaser II species decreased. During the

drought extensive grass mortality took place. Veld condition plays an important

role in determining mortality during drought. Decreaser species have a high

water requirement for optimal WUE, while Increaser II species can reach maximum

WUE with less water. Under water stress conditions Increaser II species

significantly (P<0,01) do not use the water as efficiently as do Decreaser

species. The WUE under water stress conditions for veld in good, moderate and

poor condition was on average, during the study period, 0,90; 0,90 and 0,40 kg

ha-1mm-1, respectively, and towards under optimal water conditions, 2,47; 1,67

and 0,23 kg ha-1mm-1, respectively.

Ref ID : 1100

1868. Snyman, H.A., Van Rensburg, W.L.J., and Opperman, D.P.J. Grond - en

afloopverliesbepalings vanaf natuurlike veld met behulp van 'n reenvalnabootser.

Journal of the Grassland Society of southern Africa 2(4):35-40, 1985.

Reprint : Not in File,

Keywords : SOIL EROSION; RUNOFF; LAND DEGRADATION

Ref ID : 638

1869. Snyman, H.A., Van Rensburg, W.L.J., and Opperman, D.P.J. Toepassing van 'n

gronderosievergelyking op natuurlike veld van die sentral Oranje-

Vrystaat/Application of a soil loss equation on natural veld of the central

Orange Free State. Journal of the Grassland Society of southern Africa 3(1):4-9,

1986.

Reprint : In File,

Keywords : SOIL EROSION; GRASSLAND; FREE STATE; VELD CONDITION; RAINFALL

Abstract : A rotating-boom rainfall simulator was used to obtain quantitative

data on certain parameters comprising the Universal Soil Loss Equation (USLE).

Although it was necessary to make important assumptions in this study, it was

found that there was no significant difference between the derived data and the

rainfall simulator results. This is particularly true of soil erodibility and

of the cover and management factor. An example of the use of the USLE to

predict soil losses under natural veld conditions, is discussed. A relatively

high soil loss of 3,86 t/ha/year was estimated for a pioneer grass cover (2%

basal cover) with a 4% slope in contrast to a soil loss of only 0,61 t/ha/year

from climax cover (6% basal cover) with the same slope, on a Hutton soil. There

were no significant differences in soil loss between the Hutton and Valsrivier

soils.

Ref ID : 637

1870. Snyman, H.A., Van Rensburg, W.L.J., and Opperman, D.P.J. Toepassing van 'n

gronderosievergelyking op natuurlike veld van die sentrale Oranje-

Vrystaat/Application of a soil loss equation on natural veld of the central

Orange Free State. Tydskrif.Weidingsveren.S.Afr. 3(1):4-9, 1986.

Reprint : In File,

Keywords : SOIL EROSION; GRASSLAND; VELD CONDITION; FREE STATE

Ref ID : 969

1871. Snyman, H.A., Venter, W.D., and Van Rensburg, W.L.J. Transpiration and

water-use efficiency in response to water stress in Themeda triandra and

Eragrostis lehmanniana. South African Journal of Botany 63(1):55-59, 1997.

Reprint : In File,

Keywords : PLANT PHYSIOLOGY; DROUGHT

Abstract : The influence of water stress on the rate of transpiration and water-

use efficiency(WUE) of the C4 grasses Themeda triandra Forsk. and Eragrostis

lehmanniana Nees was determined for both the vegetative and reproductive phases.

Transpiration was determined by means of an infra-red gas analyser, while the

leaf water potential was used to quantify water stress. Water-use efficiency is

defined as the ratio of mass of CO2 fixed, to mass of water released into the

atmosphere by transpiration. If water was not limiting, the rate of

transpiration was 75.8809 mg H2O m-2s-1 and 101.8384 mg H2O m-2 s-1 for T.

triandra and E. lehmanniana (P<0.001) respectively. The WUE of T. trandra and

E. lehmanniana if water was not limiting was respectively 4.2061 mg CO2 g-1 H2O

and 6.7060 mg CO2 G-1 H2O (p<0.001). The first signs of a decrease in

transpiration rate was observed at a leaf water potential of -2054 kPa for T.

triandra and -2433 kPa for E. lehmanniana (p<0.01). The decrease in

transpiration rate and WUE was significantly (P<0.01) correlated with leaf water

potential for both species. The rate of transpiration and WUE with water stress

differed significantly (p<0.01) between the two species.

Ref ID : 1101

1872. Snyman, H.A., Venter, W.D., Van Rensburg, W.L.J., and Opperman, D.P.J.

Ranking of grass species according to visible wilting order and rate of recovery

in the central Orange Free State. Journal of the Grassland Society of southern

Africa 4(2):78-81, 1987.

Reprint : In File,

Keywords : PLANT PHYSIOLOGY; GRASSLAND; DROUGHT

Ref ID : 2509

1873. Sonandi, A. Evaluation of small-scale poultry projects in rural and sub-

urban areas of the Central Eastern Cape. ARDRI News , 1996.

Reprint : Not in File,

Keywords : EASTERN CAPE; CISKEI; LIVESTOCK PRODUCTION; ECONOMIC ASPECTS

Notes : The purpose of the study was to investigate into small-scale poultry

projects developed over the last decade in rural and sub-urban areas of the

central Eastern Cape. The study was conducted through field visits. The report

contains a profile of a medium sized egg production enterprise at Rhayi near

King William's Town. The other 44 projects investigated were all small-scale

broiler units where the number of birds ranged between 20 and 300, but may be

high as 3000 in isolated cases. Participants in all the projects stated that

generating additional income for the household, is the sole purpose for being

involved in broiler production. Information on small-scale broiler production

practices is contained in the report. This article is obtainable from ARDRI,

Document Centre, Agriculture, University of Fort Hare. See ID no. 2339.

Ref ID : 363

1874. Southern African Regional Committee for the Conservation and Utilization

of the Soil Report of the sub-committee on run-off and erosion data in Southern

Africa. Sols Africains 7:207-238, 1962.

Reprint : Not in File,

Keywords : SOIL EROSION; SOUTHERN AFRICA; RUNOFF; SEDIMENTATION; INSTITUTIONAL

ASPECTS

Ref ID : 2081

1875. Southwood, A.J. Alien plant control by larger official management agencies

in the fynbos biome. 3. Department of Environment Affairs, Directorate of

Forestry : Mountain catchments areas of the southern Cape and Tsitsikama Forest

Regions. Management of invasiver plants in the fynbos biome. Macdonald, I.A.W.,

Jarman, M.L., and Beeston, P.M. Pretoria:Foundation for Research Development.

111:6-15, 1985.

Reprint : Not in File,

Keywords : ALIEN PLANTS; FYNBOS; FORESTRY; FOREST

Notes : South African National Programmes Report no. 111.

Ref ID : 1475

1876. Speight, W.L. Karroo sheep a century ago. Merino Breeders J. 24(3):21-23,

1962.

Reprint : Not in File,

Keywords : EASTERN CAPE; ENVIRONMENTAL HISTORY; FAUNA

Ref ID : 1115

1877. Spies, C.W. An approach towards the rehabilitation of degraded land. A

case study: geen einde -Sekhukhuneland. Paper presented at a conference

"Appropriate Restoration Technologies, held at Cashet Park Theatre,

Potchefstroom, 23-26 March 1998. 1998.

Reprint : In File,

Keywords : EROSION CONTROL; SOIL EROSION; ECONOMIC ASPECTS; NORTHERN PROVINCE;

RESTORATION; CONSERVATION; COMMUNAL AREA; POPULATION; POVERTY

Abstract : For environmental conservation to succeed in Communal Areas it must

be production orientated. Conservation, just for the sake of conservation, will

not work. Most of the land in the communal areas is so severely degraded that

to attempt to conserve, or maintain it in its present state, is to condemn the

present and future population to a life of permanent poverty and deprivation.

For conservation to succeed the land must be rehabilitated and the production

potential increased by the people themselves. The project at Geen Einde has

shown that local communities can be empowered to practice conservation, increase

production of their natural resoruces and to improve their quality of life.

Ref ID : 1468

1878. Stead, A. Saaidam terraces in the Karroo. Reprinted from South African

Journal of Science 21:314, 1924.

Reprint : Not in File,

Keywords : IRRIGATION; HYDROLOGY

Ref ID : 685

1879. Stead, B.A. and Stranack, A. Extension strategy to implement the

Conservation of Agricultural Resources Act (1983) on the Natal north coast.

Symposium: Communications in Successful Extension Action, 20 June 1991.Anonymous

Anonymous South African Society for Agricultural Extension: Natal Branch. :1-6,

1991. 06-20-1991.

Reprint : In File,

Keywords : AGRICULTURAL EXTENSION; GOVERNMENT INITIATIVES; POLICY; SOIL

CONSERVATION; CONSERVATION; SOIL EROSION; EROSION

Notes : The promulgation of the Conservation of Agricultural Resources Act of

1983 necessitated a change in management practices by some cane growers on the

Natal North Coast. Plouging on steep slopes and managing fields in large

blocks, instead of in panels, was considered unacceptable. In terms of the old

Act, soil erosion had to be seen to occur before the land owner could be

prosecuted. However, under the new Act the Executive Officer is empowered to

take action against any landowner whose method of farming he regards as likely

to result in excessive soil loss. Responsibility for upholding standards of

conservation on the North Coast of Natal rests with the Lower Tugela

Conservation Committee (LTCC) whose area of jurisdiction is between the Umgeni

and Tugela Rivers. The Committee comprises cane grower and miller

representatives appointed by the Minister. Extension staff of the Department of

Agriculture and Water Supply, the House of Delegates, the South African Sugar

Association Experiment Station (SASA) and the South African Cane Growers

Association are invited to attend as observers. The role of SASA Extension

Officers (EOs) on the Committee is primarily to provide technical advice.

However, they may also help to formulate Committee objectives and assist members

in their efforts to achieve their goals. During 1986 the committee members

realised that there was insufficient awareness of the provisions of the Act, and

they made it the responsibility of the members to advise all the growers in

their area and to gain their active co-operation in implementing the necessary

changes to farming practices. The strategy adopted to achieve this objective

and the results obtained are discussed.

Ref ID : 253

1880. Steinschen, A.K., G"rne, A., and Milton, S.J. Threats to the Namaqualand

flowers: outcompeted by grass or exterminated by grazing? South African Journal

of Science 92:237-242, 1996.

Reprint : In File,

Keywords : STOCKING RATE; GRAZING EFFECTS; ALIEN PLANTS; VEGETATION CHANGE;

SUCCULENT KAROO

Abstract : Annual grasses appear to be invading areas of southern Namaqualand

that are renowned for their spectacular displays of spring wild flowers. In this

study we investigated the abundance of grasses (Bromus pectinatus and Stipa

capensis), annual forbs and geophytes in ungrazed road verges and in three

rangeland sites that differed in grazing history and perennial vegetation cover.

Grazing by sheep initially reduced perennial cover on zoogenic soil mounds

(heuweltjies) and later reduced cover and diversity throughout the bottomland

landscape. The abundance of annual plants was highest where perennials were

sparse, but the diversity of annuals was reduced by grazing. Our findings

indicate that the annual flower displays are threatened by grazing rather than

by grasses, and that the awned and unpalatable grass Stipa capensis poses a

serious problem for sheep farmers.

Ref ID : 423

1881. Stephenson, D. Drought management as an alternative to new water schemes-

theory. Water SA 22(4):291-296, 1996.

Reprint : In File,

Keywords : DROUGHT; DISASTER MITIGATION; CONSERVATION

Abstract : Instead of planning water resource projects to yield a constant

maximum rate, it is advocated that reservoirs be operated on a variable draft

basis. That is, when water levels drop to predefined levels the supply rate is

decreased accordingly. This will increase the yield of the reservoirs and

reduce the necessity to build additional dams. The level of water restrictions

during drought should be sensitive to the economic consequences. If possible

the tariff should be adjusted to reduce consumption to the desirable level of

supply. Other uses of water tariffs are presented, including for repayments of

costs, subsidisation, tiered, punitive tariffs, maximum use of resources and

conservation.

Ref ID : 652

1882. Stephenson, D. and Paling, W.A.J. An hydraulic based model for simulating

monthly runoff and erosion. Water SA 18(1):43-52, 1992.

Reprint : In File,

Keywords : SOIL EROSION; RUNOFF; EROSION; MODELS; RAINFALL

Abstract : A number of rainfall-runoff computer models exist for estimating

catchment runoff from daily or monthly rainfall records. The majority of these

are based on semi-empirical models which therefore lack the ability to be

applied to new catchments without calibration. A model based on simplified

hydrodynamics equations was therefore compiled in an attempt to reproduce runoff

based on the physical laws of nature. The kinematic equations were used so that

the model does not account for backwatering or unsteady flow conditions, but

otherwise it is designed to include the effects of bed shear and the

concentration of water from overland, subsurface and stream components. Monthly

rainfall figures, which are more readily available than autographic and even

daily records, are required as well as the number of rain days per annum which

enables the program to estimate storm durations. This in turn enables runoff

rates to be estimated which in turn can be used for calculating rates of soil

erosion and transport. Infiltration into the ground is accounted for by means

of a plug-type model and subsurface flow is assumed to comprise two components.

A perched water table releases water soon after a storm, thereby creating the

recession limb of the hydrograph and infiltration from the perched water table

into a subterranean ground-water aquifer recharges the aquifer for providing dry

weather base flow into streams. The model has been tested with a number of

catchments in SA and has proved reliable with minimal calibration as would be

expected from an hydraulic-type model.

Ref ID : 494

1883. Stern, R. The effects of soil properties and chemical ameliorants on seal

formation, runoff and erosion.University of Pretoria. , 1991. Doctoral

Dissertation.

Reprint : Not in File,

Keywords : SOIL EROSION; RUNOFF; EROSION CONTROL

Ref ID : 2183

1884. Stewart, B.A. and Davies, B.R. Allochthonous input and retention in a

small mountain stream, South Africa. Hydrobiologia 202:135-146, 1990.

Reprint : Not in File,

Ref ID : 151

1885. Steyn, G.J. Amatola Basin Rural Development Project (Ciskei) III: Present

land-use: Animal production in the Amatola Basin.Anonymous Alice:Agricultural

and Rural Research Institute (ARDRI), University of Fort Hare. 6/81:1-86, 1981.

Reprint : In File,

Keywords : LAND USE; COMMUNAL AREA; EASTERN CAPE; LIVESTOCK PRODUCTION; RURAL

DEVELOPMENT; CISKEI; POPULATION; VELD MANAGEMENT

Notes : The author, in concluding this report, elucidates on the following: the

agro-ecological situation; constraints limiting production (including multiple

use of cattle, cattle ownership, livestock husbandry methods, overstocking, and

limitations of knowledge and skill); measure to increase production (including

population distribution, veld management, and extension programmes; and

research. This conclusion serves to outline dominant themes that emerge from

the findings, mentions the implicatoin of the most important of these and points

to the areas where additional research is required.

Ref ID : 2373

1886. Steyn, G.J. A farming systems study of two rural areas in the Peddie

district of Ciskei.Anonymous , 1988.

Reprint : Not in File,

Keywords : FARMING SYSTEMS; CISKEI; MODELS; LABOUR; POLICY; STATISTICS;

AGRICULTURAL PRODUCTION; BETTERMENT PLANNING; WATER CONSERVATION; AGRICULTURAL

DEVELOPMENT; RURAL DEVELOPMENT

Notes : The purpose of this study was to investigate intensively the main

factors of the farming household and its setting, through close and frequent

contact with the household members on their farms, over a period of 5 years,

considering problems and opportunities as they influence the whole farm. In

Peddie district, Nyaniso and Lujiko administrative areas were selected as

research areas. Information was gathered using questionnaires. Using the

structured questionnaire, 285 households at Nyaniso Location and 274 households

at Lujiko Location were interviewed. Analytical techniques used were

correlational analysis to investigate inter-correlation between variables and

stepwise multiple regressions to expose the possible existence of multivariate

prediction models. The study found that the study areas are not suited for

maize production. The betterment scheme has been a dismal failure in the 2

study areas. Crop production is severely constrained by the lack of

agricultural orientated organisations. A high percentage of the people are

illiterate. Shortage of farm labour, lack of water for domestic and farming

purposes are serious constraints. There are no adequate operational policies

and strategies for the development of agriculture in the rural areas of Ciskei.

The overall development of informal opinion leadership at local levels is weak

and remains securely structured within the formal tribal system. This report

can be obtained from the Document Centre, Agriculture (UFH). See ref. I.D. no:

2339.

Ref ID : 2411

1887. Steyn, G.J. The energy crisis in rural Ciskei. Africa Insight Journal ,

1990.

Reprint : Not in File,

Keywords : ENERGY; CISKEI; DEFORESTATION

Notes : The purpose of the study was to investigte the general patterns of

energy consumption in the study areas. The investigation was confined to two,

typical subsistence or below subsistence communities in the Peddie district.

The field research was done over a time span of one year, in 1986. Detailed

interviews based on a questionnaire were conducted on a sample size of 280

households in Nyaniso and 274 in Lusiko. The findings of the study show that in

subsistence households, most energy is used for cooking and heating and the