Abstract
Seeds of common endemic species of Acacia, Callitris, Eucalyptus and Melaleuca were sown at 12 sites in Southern Australia in 1994 and 1995 to determine the role of soil stabilisers, fertilisers, time of seeding, herbicides, ripping and soil preparation with a V-blade or a disc in improving the reliability of direct seeding in Mediterranean type climates with low rainfall. Rainfall in 1994 was below average with 140 mm at the northern sites (55% of the average) and 300 mm at the southern sites (74% of the average) and only Acacia was successful with at least 3 plants/10 m present at the end of spring at eight sites and a survival rate after the first summer of 43%. In 1995 at least 3 plants/10 m of Acacia and Eucalyptus spp. were present at the end of spring at eight sites, with at least 3 plants/10 m of Melaleuca at six sites and at least 3 plants/10 m of Callitris at only three sites. Melaleuca had the highest overall survival rate at the end of summer with 52% compared to Acacia 42%, Eucalyptus 41% and Callitris 29%. Sowing two to three weeks after the opening rains (May at most sites) with good weed control gave the best results. Plant survival over the summer was reduced by 40% where weeds were not controlled by a herbicide. Ripping or fertiliser did not improve success. Ground preparation with an 80 cm wide V-blade generally produced better results than using a 25 cm wide disc except for Melaleuca. The effect of bitumen was variable in the trials, but appeared to be beneficial on wind eroded sites. The results indicate that direct seeding of trees and shrubs can be carried out in Mediterranean type climates with 250 to 425 mm average annual rainfall including on soils that are water repellent. This technology could be used for large scale revegetation in areas of the world with low rainfall Mediterranean type climates that have been largely denuded of trees and shrubs.
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Bird PR, Bicknell D, Bulman PA, Burke SJA, Leys JF, Parker JN, Van Der Sommen FJ and Voller P (1992) The role of shelter in Australia for protecting soil, plants and livestock. Agroforestry Systems 20: 59–86
Dalton GS (1993) Direct seeding of shrubs and trees, a manual for Australian conditions. Primary Industries SA, Adelaide, South Australia, pp 53–57
Dixon RK, Winjum JK, Andrasko KJ, Lee JJ and Schroeder PE (1994) Integrated land-use systems — assessment of promising agroforest and alternative land-use practices to enhance carbon conservation and sequestration. Climatic Change. 27(1): 71–92
Edessa S (1993) The decline of forests and natural resources in Ethiopia. Ekologia-Bratislava 12(2): 215–222
King PM (1981) Comparison of methods for measuring severity of water repellence of sandy soils and assessment of some factors that affect its measurement. Australian Journal of Soil Research 19: 275–285
Mabbut JA (1981) A new global assessment of the status and trends in desertification. Environ Conserv 11: 103–113
Nodolny C and Morsley R (1994) Experiment on effect of time of sowing and bitumen mulch. Proceedings of the Direct Seeding Research Workshop, Cowra, Primary Industries South Australia, pp 109–113
Thirgwood JV (1981) Man and the African forest. Academic Press, London
Zaimeche SE (1994) The consequences of rapid deforestation — a north African example. Ambio 23(2): 136–140
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Knight, A.J.P., Beale, P.E. & Dalton, G.S. Direct seeding of native trees and shrubs in low rainfall areas and on non-wetting sands in South Australia. Agroforestry Systems 39, 225–239 (1997). https://doi.org/10.1023/A:1005901111273
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DOI: https://doi.org/10.1023/A:1005901111273