Finlayson J.,University of Western Australia |
Bathgate A.,Farming Systems Analysis Service |
Nordblom T.,Charles Sturt University |
Theiveyanathan T.,ENSIS |
And 4 more authors.
Agricultural Systems | Year: 2010
It has been widely suggested that changing land use from annual to perennial crops reduces land and stream degradation due to salinisation. However, annual crops are financially attractive and increases in perennials can reduce stream flows with adverse effects on stream values. As such, salinity control is likely to involve tradeoffs between public and private costs and benefits. This study quantifies the expected on-farm economic and catchment-level water yield and salinity effects of altering land use among trees, perennial pastures and cereals. The structure of a two stage linear-programming (LP) process is described. The first stage is the MIDAS farm-level model of mixed cropping and sheep enterprises which provides inputs to a second stage catchment-level LP. It was concluded that perennial pastures can be used in conjunction with trees as a stream salinity-management tool in low to intermediate rainfall areas in New South Wales. The results indicate that land-use decisions should be informed by site-specific information if adverse effects on streams are to be avoided. © 2009 Elsevier Ltd. All rights reserved.
LIN X.-Y.,Zhejiang University |
LIN X.-Y.,China National Rice Research Institute |
WANG Y.,Zhejiang University |
WANG H.-L.,Ensis |
And 3 more authors.
Pedosphere | Year: 2010
The objectives of this study were to isolate a bensulfuron-methyl (BSM)-degrading strain of Bacillus spp. and to evaluate its effectiveness in remediation of a BSM-contaminated soil. A BSM-degrading bacterium, strain L1, was successfully isolated in this study. Strain L1 was identified as Bacillus megaterium based on its morphological, physiological, and biochemical properties, G+C content, phylogenetic similarity of 16S rDNA, and fatty acid composition. Two experiments were used to examine BSM degradation by strain L1. When BSM was used as a sole carbon source in a mineral salt medium, the average degradation rate of BSM by strain L1 was 12.8%, which suggested that the strain was able to utilize BSM as a sole carbon and energy source. Supplement of yeast extract (200 mg L-1) significantly (P ≤ 0.01) accelerated the degradation of BSM by strain L1. Almost complete degradation (97.7%) of BSM could be achieved in 84 h with addition of yeast extract. In addition, in a sterile soil with 50 mg L-1 BSM, BSM degradation rate by strain L1 was 94.3% in 42 d, indicating the potential of using microbes for the remediation of BSM-contaminated soils in fields. © 2010 Soil Science Society of China.
Jia Y.F.,Zhejiang University |
Shi W.Y.,Zhejiang University |
Wu L.H.,Zhejiang University |
Journal of Tropical Forest Science | Year: 2011
Bamboo shoot shells (BSS) can be used as feedstock for the production of natural fibre. The purpose of this study was to preserve BSS in ensilage for further application as fibrous material. Lower silage pH and higher concentrations of dry matter and protein were found in the treatments with addition of cellulase and hemicellulase, and lactic acid bacteria (LAB) than in the control with no additives. The LAB treatment was most effective resulting in the highest concentration of total organic acids and lowest concentration of ammonia nitrogen. The structural changes in ensilaged fibres with LAB treatment were analysed and compared with untreated fresh BSS fibres using infrared spectrometer, X-ray diffraction and thermal analysis system techniques. Infrared spectrometer analysis demonstrated changes in the content of cellulosic components in the ensilaged fibres. X-ray diffraction analysis showed increase in the crystallinity of the ensilaged fibres. The thermal stability of the ensilaged fibres was improved, with slight shift of the maximum decomposition rate under higher temperature, from 320 to 327 °C. The beneficial characteristics of BSS fibres imply that ensilage can potentially be used as an effective storage method, which is essential for commercial production of high value fibrous materials. © Forest Research Institute Malaysia.
Hu H.-R.,Southwest Forestry College |
Wang H.-L.,Ensis |
Huanjing Kexue/Environmental Science | Year: 2010
Treated sewage effluent from Rotorua City, New Zealand, has been spray-irrigated into Whakarewarewa Forest to minimize effluent-derived nitrogen (N) and phosphorus (P) entering Lake Rotorua. To assess the capacity of the ecosystem to assimilate the effluent derived nutrients, a long term field trial was established within the Rotorua land treatment system. The objective of this study was to determine the accumulation, redistribution and movement of P in the volcanic soil after 11year effluent irrigation. The soil samples were analyzed. Soil pH, total phosphorus (TP), Olsen P, Mehlich-3 P(M3P), M3Ca and M3Mg had increased significantly (p<0.05) in the top soil (0-10 cm) in all effluent treated plots compared with the control plots. Some significant increase had extended deeper soil layer (20-40 cm) or much deeper soil layer. Most effluent-derived P had accumulated in top 40 cm. Concentrations of soil Olsen P and M3P in the medium and high effluent treatments were over environmental threshold levels(Olsen P, 60 mg·kg -1; M3P, 150 mg·kg -1) in the top 20 cm. The values of soil saturation ratio (M3PSR) show that it was nearly saturated of soil P sorption in top soil. It was suggested that there was a potential environment crisis for soil P to move downward with drainage water. Regular soil sampling and Olsen P measurement using 60 mg·kg -1 as an environment threshold could provide a solution for monitoring the movement of P down the soil profile. Phosphorus saturation ratio index (M3PSR) calculated as the molar ratio of M3P to (M3Al + M3Fe) appeared to be inadequate as an indicator for downward movement of soil P in such land treatment system. A new Phosphorus saturation ratio index for this system will be one of future study work.