School of Agriculture, Food and Ecosystem Sciences - Theses

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Villager participation in native forest development : the impact of social forestry in Fiji

Vize, Susan Maree (University of Melbourne, 1993)

As owners of extensive forest resources, the Fijian people have an opportunity to utilise these resources for village development. Villagers are very conscious of their low living standards compared with urban areas. It is widely accepted that expanding local employment and business opportunities is necessary to improve rural living standards, and rural Fijians hope that the forest industry will help them to achieve this. The object of this research project is to evaluate the success of social forestry as a methodology for achieving village development in Fiji, particularly the contribution of Fijian villager participation in the native forest industry. Forestry activities earn cash benefits for rural villagers in the forms of land rentals and timber royalties. Social forestry programmes involving villager participation in planting projects were seen as way to enhance rural development. To further increase the benefits obtained from forestry many Fijians have become actively involved in forest harvesting and timber processing. Though there is a high potential for achieving significant benefits by Fijian participation in the forestry industry, the actual benefits received are determined by the type of activity, the level of participation and the performance of the participants. The study involved surveying in seven villages on the islands of Viti Levu and Vanua Levu, as well as short interviews with many Fijians involved in the forest industry. The villages covered a range of villager forestry participation types, including casual and contract employment in logging or planting, village community fund-raising contracts, a proposed joint venture logging project and a small logging company. 'Development' appears to be fairly consistently interpreted across rural Fiji as the improvement of village services and homes; hence in the eyes of the villagers, forestry does contribute to development. The surveys show that forestry can make a significant contribution to the village economy in the form of cash and employment, but the contribution of forestry towards village development is dependent upon the use of the income generated from forestry. These uses vary between the villages, but commonly include the purchase of consumables, such as food and tobacco, paying school fees, home improvements, roads, churches, schools, and other communal amenities. There is a significant difference in the contribution of forestry to employment and income between the two islands; forestry is more important in rural development on Vanua Levu. Social structure in the village, village leadership, assistance from government or financial advisers, and the level of integration of the village into the market economy, all appear to affect the investment and management of forestry funds. These aspects exert the most influence on the amount of 'development' that can be achieved through forestry programmes involving Fijian landowners. Logging businesses achieved higher cash returns than other types of Fijian forestry participation, but were plagued by difficulties. Businesses in logging, sawmilling and manufacturing of higher value-added products such as veneer and furniture are the most profitable area of the forest industries in Fiji. The potential for Fijian villagers to become involved in these enterprises is severely limited by access to credit as well as their paucity of management and administrative skills. But where the potential for forestry participation exists and motivation is provided by a community leader or individual, social forestry activities can effectively promote rural development and viable village communities in Fiji.
Estimation of timber volumes in eucalypt forest using large-scale aerial photography and ground samples

Biggs, Paul Haydn (University of Melbourne, 1991)

This study investigated the use of large-scale aerial photographs (1:1200) for estimating timber volumes in eucalypt forest in Western Australia. The aims were to determine the optimum photography system for estimating timber volumes in jarrah forest, to derive appropriate aerial volume functions, and to investigate the efficiency of different sampling designs using aerial photographs. Photographs were acquired using a fixed-base photographic system, the cameras being mounted on a transverse boom on a helicopter. Two types of cameras, Vinten and Hasselblad, were tested. Measurement of the Vinten photographs using simple stereometers provided estimates of tree heights with a standard deviation of 1.7 m, while the standard deviation of measurements on Hasselblad photographs was about 2.0 m. These results are slightly poorer than results achieved by others in coniferous forests, the reason being attributed to imprecision of the ground "truth" rather than poor quality in the photographs. The accuracy of species interpretation was 85 percent on all photographs. It is expected that more precise measurements could be obtained using analytical plotters to measure Hasselblad photographs. Hasselblad 500 EL/M cameras used in the present study were fitted with reseau plates and were calibrated to facilitate analytical measurement. Results showed, however, that further research is required into the process of exterior orientation with such large-scale photographs with a very small air-base/flying height ratio. A system of navigation and camera-control was built specially for this project using a Global Positioning System (GPS) receiver and a laptop computer. This system was used to navigate during photography and to determine the location of each pair of photographs on maps and in the field. Its use led to efficient in-flight navigation and ensured that photographs were taken on a fixed-distance interval. Ground plots could be located quickly in the forest using this system, as the actual photo-centres were generally within 50 m of their surveyed position based on GPS coordinates. Sample data from both photo and ground plots were stored in a Geographic Information System (GIS) database, which allowed them to be linked with other spatial data. Using this system, volume statements could be derived for any part of the forest by defining the relevant geographical zone and then identifying the plots within that zone. Any change in the available land base could also be accomodated, simply by redefining the zone of interest and reselecting the sample plots. Aerial tree volume functions derived for different species in the jarrah forest used the total height of each tree and the dominant height of the stand as independent variables. Separate functions were derived for different areas of forest by applying a nominal dominant height value in a general volume function, while another set was derived by stratifying the original sample plots. It was found that the volumes of very large trees were greatly underestimated when their crowns had been damaged, and that this factor swamped the difference between the two types of volume functions. The underestimates of photo volume caused by the damaged crowns of large trees had the effect of reducing the correlation between the photo and ground samples to about r=0.65. The cost of each photo plot was about $30 and the cost of each ground plot was $280. The combination of these costs and correlation meant that double sampling for regression could provide estimates of volume at the same cost and precision as ground sampling. Further research should, however, investigate ways to improve this correlation to about r=0.75, which would then make double sampling with large-scale photographs cheaper than ground sampling.
Innovation in response to environmental problems

Ewers, Craig. (University of Melbourne, 1990)

An important and long-standing field of agricultural extension research has involved the acceptance of new agricultural practices. Consistent with the applied, purposive nature of extension research and the emphasis on agricultural development, this field has centred around the question: How do we get farmers to adopt new technology? As such, the process has traditionally been viewed as one which is confined to the decisions of individual farmers. The role of those who develop and distribute the technology has generally been overlooked. It is argued in this thesis that when the development and promotion of agricultural technology are an integral part of government strategy, a great deal of decision-making happens before the technology even reaches the farm. Indeed, it will be shown that some innovations developed by government scientists may not become fully available to farmers. The complex interplay between science, technology and government policy forms a central theme throughout this thesis. Changes in agricultural practice are discussed with reference to the social and economic conditions that triggered them. In particular, the growing impact of the environmental movement on the development and diffusion of new cropping techniques throughout the 1980s is covered in depth. Two current Victorian government programs are critically reviewed along these lines. Finally, the views of farmers are analysed, through a survey of 146 wheat growers in North-East Victoria.
Tribes and territories : aspects of Aboriginal political geography in the Northern Territory of Australia

Davis, Stephen, 1951- (University of Melbourne, 1989)
Control of the black field cricket teleogryllus commodus (walker) (orthoptera: gryllidae) in Victoria

Murphy, Graeme, 1954- (University of Melbourne, 1985)

Techniques for improving control of the black field cricket Teleogryllus commodus were studied between 1981 and 1985 in series of laboratory and field trials in the western district of Victoria. In the laboratory, techniques were developed for assessing the palatability of substances to T. commodus. A number of plant extracts, especially water and acetone extracts from grasses, and other substances including sucrose and vegetable oils were shown to stimulate feeding in the cricket. Further laboratory trials showed that feeding stimulants could be used to encourage feeding on a commonly used substrate in cricket baits (wheat). Field trials to assess bait attractiveness revealed oats to be more attractive as a bait than wheat or barley. Efficacy trials conducted over consecutive years however, showed no differences in the level of control achieved with baits using wheat, oats or barley as the substrate. In addition, feeding stimulants added to the bait did not improve control, nor did the use of higher baiting rates. The level of control obtainable with the current recommended bait is between 80% and 95%.
Genotype environment studies in Pisum Sativum L. in relation to breeding objectives : ideotypes of pea

Berry, G. J. (University of Melbourne, 1981)

The overall objective of this thesis is to provide the information necessary to produce new varieties of pea which are more productive, easier to harvest and better suited to present day markets. This thesis defines ideal plant types (ideotypes) of pea and outlines how a breeding programme could produce and test them. Some effects of genotype and environment on morphology, development, growth, nodulation and yield component interactions are documented. Sets of near-isogenic lines, segregating populations and collection lines were grown in environments varying for photoperiod, temperature, daily radiant flux and soil nutrient levels. The results obtained, and reviews of the literature, provided the knowledge necessary to specify ideotypes. The ideotypes are defined at two levels: 1. Traits which confer benefits in terms of increased general adaptation to cropping systems, and 2. Traits which are specific to particular cropping systems and product uses. Increased general adaptation of pea should result from changes to plant form (e.g., leaflets replaced by tendrils, pods clustered at the top of the plant instead of being spread along the stems) and appropriate manipulation of yield components (e.g., high number of seeds/pod rather than many pods/node). Also, total yield of agricultural products from a crop rotation system will depend, in part, on the nitrogen fixing, ability of the pea crop. The time of flowering is an important trait conferring adaptation to specific cropping systems. The ideotypes have a condensed flowering period compared with current cultivars, so it becomes critical that flowering occurs at the optimum time. Models to predict the time of flowering from climatic data are presented for a range of genotypes. Other traits required in specific situations are determined by aspects such as market preferences and disease and insect problems. The genetic control of most of the ideotype traits is known and is relatively simple, so new plant types could be produced rapidly. A breeding programme based on the ideotype concept could use backcrossing to a recurrent parent to combine the desired traits into one plant type. It would be wise to do this on a range of genetic backgrounds and it would be necessary to test the new plant types for negative gene interactions and detrimental pleiotropy.
The soil-root interface of Lupinus Albus L. and its significance in the uptake of manganese, iron, and phosphorus

Gardner, W. K. (William K.) (University of Melbourne, 1981)

It has been demonstrated using an agar film technique that L.albus is able to dissolve colloids of iron/silicate, iron/ phosphate, aluminium/silicate and aluminium/phosphate and also suspensions of manganese dioxide, calcium mono-hydrogen phosphate and ferric hydroxide. Dissolution of these compounds was most marked in proteoid root regions of lateral roots (dense clusters of 20 laterals of limited growth) and certain regions of the tap root. Soil associated with these root regions was found to contain more protons, reductants and chelating agents than the bulk soil. The effect of iron and phosphorus nutrition was examined in acid washed sand. The effect of phosphorus nutrition was also examined in three soils (acid, neutral and alkaline) under glasshouse conditions. The response of wheat, L.angustifolius and L.albus to phosphorus was compared at three sites (acid, neutral and alkaline) in field trials. Proteoid root formation was found to be predominantly controlled by the phosphorus status of the plant. Manganese uptake in L.albus was related to proteoid root formation, and inversely related to phosphorus supply in both L.albus and L.anqustifolius. The ability of L.albus to utilise soil and added phosphorus decreased as the pH of the soil increased. The role of micro-organisms in proteoid root formation and function was investigated. Proteoid roots formed under sterile conditions, but more formed under non-sterile conditions. The effect of varying root morphology on exudation characteristics in the rhizosphere was examined by computer simulation. The main exudate from the roots of L.albus has been identified by gas-liquid chromatography and mass spectrometry as citric acid. It is hypothesised that citrate ions react with the soil colloid and form a diffusible polymeric ferric hydroxy phosphate which moves to the root surface where it is broken up by a combination of ferrous ion uptake, proton secretion and reduction. An attempt has been made to examine iron in the roots using electronmicroscopy and X-ray microprobe. The results suggest that iron is mobilised about the root system in large amounts, although this is not reflected in above ground parts. The effect of intercropping wheat and L.albus was examined in both glasshouse and field for effects on the mineral nutrition of both species. Wheat intercropped with lupins appears to have access to a larger pool of available phosphorus, manganese and nitrogen than has wheat grown on its own.
Aspects of the biology and salt tolerance of Phragmites australis (Cav.) Trin. ex Steud.

Clucas, Rowena D. (University of Melbourne, 1980)

Reeds thrive under a wide range of conditions, but in the Gippsland Lakes system, high salinity levels - both alone and in conjunction with other environmental factors - have greatly reduced Phragmites growth on the shoreline and removed the reed fringe entirely in some areas. The Gippsland Lakes system provides an unstable environment, where salinity levels and water levels fluctuate seasonally and also between drought and flood years. Distribution of reeds along the lake edges is correlated primarily with salinity levels, but also with exposure to wind, wave and current action. The amount of salt absorbed by reeds is directly related to site salinity. High salinities reduce many aspects of productivity, including shoot height, density and dry weight, and seed production. The actual salinity tolerance of Phragmites in the field is dependent upon the severity and duration of the salinity regime and other habitat factors operating. Conditions on the north shore of Lake Wellington are near the tolerance limit of Phragmites. Reeds accumulate large quantities of mineral elements and growth is greatly improved in areas of high nutrient status. Phragmites can readily be grown from rhizome or shoot cuttings if these are collected at the appropriate stage of development. Establishment from seed is a rare occurrence in the field and germination depends on the formation of viable fruits. In the three Victorian populations studied, less than two per cent of the florets contained viable seed.
Efficiency of nitrogen fertilization of dry-seeded rice in south-east Australia

Humphreys, Elizabeth ( 1986)

The efficiency and fate of fertiliser nitrogen applied to combine-sown rice were investigated in field experiments in which fertiliser timing, water regime and soil type were varied. The information gained was used to predict strategies for optimising fertiliser efficiency using current techniques, and to predict and test improved fertilisation technologies. The stage of crop growth, water regime and soil properties all had large and interacting effects on agronomic efficiency. On an infertile alkaline grey clay soil, agronomic efficiency of urea applied at sowing was very low (8 kg kg-1) compared with later applications associated with continuous flooding (up to 56 kg kg-1). The low efficiency was due to nitrification and subsequent de-nitrification during the flushing period. Nitrogen-15 balance studies indicated that 80% of the urea nitrogen was lost from the soil-plant system. The rapid nitrification rate and high loss of nitrogen on the grey soil contrasted with the very low levels of nitrate and low losses of nitrogen (10-25%) from urea applied to rice growing on an infertile acidic red soil under alternating conditions of saturation and aeration (sprinkler-irrigation). Furthermore, on a fertile acidic red soil in the same region, other authors have measured large yield responses to nitrogen applied at sowing. These differences highlight the need to consider soil properties and water management when attempting to predict optimum fertilisation strategies. Yields of sprinkler-irrigated rice (managed to replace water lost by evaporation) were reduced by more than 50% compared with rice grown under continuous flood. However, this was not due to decreased plant uptake or increased loss of fertiliser nitrogen in the sprinkler-irrigated treatments. The low yields appeared to be associated with plant water stress, decreased nitrogen mineralization (by approximately half) and location of the fertiliser nitrogen near the soil surface where root activity was probably restricted due to inadequate moisture. On the grey soil, maximum agronomic efficiencies occurred with application shortly before permanent flood or at early panicle elongation. Efficiency was doubled when urea was applied before permanent flood compared with shortly after permanent flood. The greater efficiency appeared to be associated with the deeper transport of the applied nitrogen into the soil, and consequently lower losses by ammonia volatilisation and/or nitrification/de-nitrification. However, even with the most efficient fertilisation strategies, plant 15N recoveries were less than 40%, while losses exceeded 20%. When the 15N balance data were considered in conjunction with the agronomic data,. it appeared that it would be possible to further increase agronomic efficiency if plant recovery of applied nitrogen could be increased. In particular, minimisation of losses of nitrogen (via nitrification/de-nitrification) from fertiliser applied before permanent flood was a most attractive option. Potential methods identified for increasing agronomic efficiency by minimising losses of nitrogen applied before permanent flood were deep placement and the use of nitrification inhibitors and slow release nitrogen sources. Several experiments were conducted in an attempt to improve fertiliser efficiency by banding urea and modified urea sources 5-7 cm below the soil surface before permanent flood. Plant recovery of 15N was increased by up to 20% with banding compared with surface broadcasting. The best recoveries were from urea super-granules (USG). An experimental fertiliser rig and a commercial seeder fitted with a triple disc assembly were used to band the fertilisers in the main plots. There was no significant yield advantage with banded urea over broadcast urea applied before permanent flood. The fertiliser rig caused considerable plant damage. Using the triple disc applicator, it was possible to band fertiliser below the soil surface with minimal soil disturbance, and plant damage, but only under i ideal conditions of soil moisture. Furthermore, where the soil surface was dry and cracked, penetration with the triple discs was no greater than the depth of the cracks into which surface applied urea prills would be washed upon flooding. The yield test of USG was unsatisfactory because of the excessive plant damage with this method. With current technology, there appears to be little scope for improving the efficiency of urea applied before permanent flood by mechanical placement below the soil surface.
An economic analysis of Nigeria's import substitution policy for rice and wheat

Matane, Ibrahim Ahmed ( 1993)

The study involves analyses of substitution effects of Nigeria's import restriction imposed on rice and wheat; in terms of domestic production, consumption and prices. The theoretical and empirical literature on uncertainty, risk and self sufficiency under international trade is reviewed, as well as smuggling and its welfare implications. The analyses involves use of regression and correlation models. The result shows that increase in price of wheat would reduce per capita wheat consumption, thereby shifting consumption to maize and millet. It is found that wheat and rice are inferior commodities in Nigeria. In addition, increase in the prices of yam and maize would increase per capita rice consumption . Therefore, yam, maize and rice are substitutes in consumption, so also are wheat and rice in production. An increase in price of rice would increase rice area while increases in prices of maize and wheat would increase wheat area. While increase in the price of rice would lower wheat production, thereby favouring rice production in the longrun. Accordingly, increase in world prices for rice and wheat would lower their domestic prices. While increase in tariff would increase domestic wheat producer price. Between 1973 and 1986 prices of most food commodities in Nigeria increased both nominally and in real terms. In addition, real prices for rice and wheat slumped between 1987 and 1989. Retail prices were always higher than producer prices. It is concluded that insulating domestic prices and supplies of rice and wheat is no panacea to problems associated with price instability, self sufficiency and balance of payments. Sustainable policies, such as consumption tax; use of futures markets; diversification and appropriate exchange rate are the best policy options.

School of Agriculture, Food and Ecosystem Sciences - Theses

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