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The Veterinary record 09/2008; 163(8):253-4. · 1.25 Impact Factor
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ABSTRACT: Irrigation of tree crops is being evaluated as a method of land disposal of municipal effluent in Australia. A study was carried out from 1980-84 in which seven tree species were sprinkler-irrigated with effluent at an annual rate of 1191-1752 mm. Effective weed control and frequent irrigation resulted in good survival of all species (range 83-100%) at 12 months. Total productivity was estimated at age 4 years by measuring biomass of each species inclusive of litter and roots to a soil depth of 80 cm. Biomass production of the high-yielding species, flooded gum (Eucalyptus grandis) and Sydney blue gum (E. saligna), was around 10 kg m(-2). Percentage leaf mass of these species was small (8-9%) compared with 25% and 29% for the relatively slow-growing river she-oak (Casuarina cunninghamiana) and radiata pine (Pinus radiata). Accumulation of nutrients in the total biomass differed significantly between species and ranged from 34-54 g m(-2) for nitrogen, 4.0-10.4 g m(-2) for phosphorus, 2.1-12.2 g m(-2) for sodium, 22-34 g m(-2) for potassium, 12-61 g m(-2) for calcium and 4.7-9.3 g m(-2) for magnesium. River she-oak and river red gum (E. camaldulensis), because of their relatively large crown and litter masses, accumulated more nitrogen, phosphorus, potassium and calcium than flooded gum or Sydney blue gum. Chemical properties of soils (0-150 cm) were measured in 1980 and again in 1984. Irrigation significantly increased pH (by around 1 unit), throughout the profile. Concentrations of total phosphorus, and exchangeable sodium, calcium and magnesium were increased in the upper profile. Overall, soil chemical properties were not adversely affected by effluent irrigation over the 4-year period, though there was a trend towards more sodic conditions in the soil profile. Nutrient accumulation in soil occurred mainly in the 0-35 cm depth, coinciding with the main root zone of the trees. Renovation of the effluent was therefore estimated as the amount of each nutrient accumulated in the biomass (averaged over the seven species) plus soil (0-35 cm), expressed as a percentage of amount applied in irrigation over the 4 years; that is, nitrogen, 29%; phosphorus, 78%; sodium, 15%; potassium, 26%; calcium, 98% and magnesium, 54%.
Environmental Pollution 02/1990; 63(2):155-77. · 3.75 Impact Factor
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ABSTRACT: Irrigation of tree crops is being evaluated as a method of land disposal of municipal effluent in Australia. A study was carried out from 1980–84 in which seven tree species were sprinkler-irrigated with effluent at an annual rate of 1191–1752 mm. Effective weed control and frequent irrigation resulted in good survival of all species (range 83–100%) at 12 months. Total productivity was estimated at age 4 years by measuring biomass of each species inclusive of litter and roots to a soil depth of 80 cm. Biomass production of the high-yielding species, flooded gum (Eucalyptus grandis) and Sydney blue gum (E. saligna), was around 10 kg m−2. Percentage leaf mass of these species was small (8–9%) compared with 25% and 29% for the relatively slow-growing river she-oak (Casuarina cunninghamiana) and radiata pine (Pinus radiata). Accumulation of nutrients in the total biomass differed significantly between species and ranged from 34–54 g m−2 for nitrogen, 4·0–10·4 g m−2 for phosphorus, 2·1–12·2 g m−2 for sodium, 22–34 g m−2 for potassium, 12–61 g m−2 for calcium and 4·7–9·3 g m−2 for magnesium. River she-oak and river red gum (E. camaldulensis), because of their relatively large crown and litter masses, accumulated more nitrogen, phosphorus, potassium and calcium than flooded gum or Sydney blue gum. Chemical properties of soils (0–150 cm) were measured in 1980 and again in 1984. Irrigation significantly increased pH (by around 1 unit), throughout the profile. Concentrations of total phosphorus, and exchangeable sodium, calcium and magnesium were increased in the upper profile. Overall, soil chemical properties were not adversely affected by effluent irrigation over the 4-year period, though there was a trend towards more sodic conditions in the soil profile. Nutrient accumulation in soil occurred mainly in the 0–35 cm depth, coinciding with the main root zone of the trees. Renovation of the effluent was therefore estimated as the amount of each nutrient accumulated in the biomass (averaged over the seven species) plus soil (0–35 cm), expressed as a percentage of amount applied in irrigation over the 4 years; that is, nitrogen, 29%; phosphorus, 78%; sodium, 15%; potassium, 26%; calcium, 98% and magnesium, 54%.
Environmental Pollution.
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ABSTRACT: In the Murray-Darling basin, irrigation of tree crops is being evaluated as an alternative method for the disposal of municipal effluent. A study was carried out at Wodonga in which seven tree species were irrigated with effluent for a period of 4 years. Irrigation was calculated weekly on the basis of pan evaporation and rainfall during the preceding week. Annual irrigation varied between 1190 mm and 1750 mm with a total input over the 4-year-period of 4940 mm.Height and diameter growth varied significantly between species. At age 4, mean dominant height of Eucalyptus grandis, E. saligna and Populus deltoides × P. nigra ranged from 14.3 to 15.0 m compared with 6.6 to 9.8 m for Casuarina cunninghamiana, E. camaldulensis, P. deltoides and Pinus radiata. Wood production of the faster-growing species (E. grandis and E. saligna) was approximately 130 m3 ha−1, or around 32 m3 ha−1 year−1 over a 4-year period. This was nearly three-fold the production of the other native species and twice that of Pi. radiata. Volume growth of P. deltoides × P. nigra (85 m3 ha−1) was significantly greater than that of P. deltoides (42 m3 ha−1).Accumulation of nutrients in the above-ground biomass varied significantly between species and ranged from 24 to 41 g m−2 for N, 2.6 to 5.9 g m−2 for P, 0.5 to 9.2 g m−2 for Na, 12 to 27 g m−2 for K, 7 to 52 g m−2 for Ca and 3.1 to 7.9 g m−2 for Mg. Nutrient accumulation was generally greater in species with a comparatively large crown biomass relative to stem size such as C. cunninghamiana and E. camadulensis. Average nutrient accumulation by trees as a percentage of input from effluent was estimated at 19% for N, 9% for P, 1% for Na, 14% for K, 52% for Ca and 32% for Mg.Results of this study indicate the importance of selecting species on the basis of not only growth but also nutrient accumulation to optimise renovation of wastewater by tree plantations.
Forest Ecology and Management 30:203-211. · 2.49 Impact Factor
