• Authors:
    • Rodriguez-Moran, M.
    • Garcia-Olmos, B.
    • Andujar, S.
    • Navarro, J. M.
    • Perez-Tornero, O.
    • Morte, A.
  • Source: Acta Horticulturae
  • Issue: 922
  • Year: 2011
  • Summary: Arbuscular mycorrhizal (AM) symbiosis is thought to increase host resistance to salinity stress, a characteristic that could be interesting in areas where the scarcity of irrigation waters forces growers to use low-quality irrigation water. To test this hypothesis seedlings of the rootstocks Mandarin Cleopatra ( Citrus reshni Hort. ex Tan.), Sour orange ( Citrus aurantium (L.)) and Alemow ( Citrus macrophylla Wester) were grown in a growth chamber and inoculated with a mixture of two AM fungi ( Glomus intraradices and Glomus mosseae) (IP), or left non-inoculated (NIP). From forty-five days after fungal inoculation onwards plants were irrigated with nutrient solution containing 50 mM NaCl and, three months after inoculation, the growth, mineral nutrition and physiological response were analysed. AM fungi significantly increased all plant growth parameters studied, especially in the Cleopatra and Alemow rootstocks. In general, plant growth parameters were higher in salinized IP plants than in non-salinized NIP plants, demonstrating that AM colonization compensates for the growth limitations imposed by saline conditions. The water content was higher in IP plants of Cleopatra and Alemow but not in the Sour orange seedlings. Under saline conditions NIP Alemow plants had a strongly-decreased water content, while the water content of IP Alemow plants was similar to that of non-salinised plants. In all three rootstocks, NIP plants showed a greater degree of salt-induced foliar damage and chlorosis than IP plants. Although IP plants were not fertilised with phosphorus in the experiment, they had significantly higher levels of this nutrient in roots, stems and leaves than NIP plants both in salinised and control plants. The beneficial effect of mycorrhization appears to be unrelated with protection against the uptake of excess of Na + or Cl - by the plant. Our findings confirm that AM fungi can alter host responses to salinity stress, improving the P nutrition and diminishing chlorosis and salt damage.
  • Authors:
    • Sheffield, K. J.
    • Abuzar, M.
    • Whitfield, D. M.
    • O'Connell, M. G.
    • McClymont, L.
    • McAllister, A. T.
  • Source: Acta Horticulturae
  • Issue: 889
  • Year: 2011
  • Summary: SEBAL-METRIC estimates of evapotranspiration (ET) were derived from Landsat-5 imagery of Sunraysia Irrigation Region of Victoria, Australia. Paired estimates of ET and vegetation cover, NDVI, were derived from an image taken mid-season on 5 January 2009. NDVI and ET were attributed to land use based on data provided by SunRISE21 Inc. Relationships between ET, scaled by field measured reference tall crop evapotranspiration, ET r, and NDVI for the dominant almond, citrus and grape crops showed that the evaporation ratio (ET/ET r) was strongly related to NDVI. These findings suggest that SEBAL-METRIC satellite remote sensing approaches offer an affordable and robust method for the deviation of NDVI-based block-customised estimates of crop coefficient (K c) for almond, citrus and grape crops.
  • Authors:
    • Barton, L.
    • Butterbach-Bahl, K.
    • Kiese, R.
    • Murphy, D. V.
  • Source: Global Change Biology
  • Volume: 17
  • Issue: 2
  • Year: 2011
  • Authors:
    • Eckard, R. J.
    • Browne, N. A.
    • Behrendt, R.
    • Kingwell, R. S.
  • Source: Animal Feed Science and Technology
  • Volume: 166-167
  • Year: 2011
  • Authors:
    • Grace, P.
    • Barton, L.
    • Chen, D.
    • Eckard, R.
    • Kelly, K.
    • Officer, S.
    • Scheer, C.
    • Schwenke, G.
    • Wang, W.
  • Source: Soil Solutions for a Changing World
  • Year: 2011
  • Authors:
    • Huggins, T.
    • Kelly, K.
    • Suter, H.
    • Eckard, R.
  • Source: The CCRSPI Conference
  • Year: 2011
  • Authors:
    • Chen, D.
    • Barton, L.
    • Li, Y.
  • Source: Journal of the Science of Food and Agriculture
  • Volume: (in press).
  • Year: 2011
  • Authors:
    • Byrant, G.
    • White, I.
    • Denmead, O. T.
    • Macdonald, B. C. T.
  • Source: Pedosphere
  • Volume: 21
  • Issue: 2
  • Year: 2011
  • Authors:
    • Van Zwieten, L.
    • Kimber, S.
    • Rowlings, D. W.
    • Grace, P. R.
    • Scheer, C.
  • Source: Plant and Soil
  • Volume: 345
  • Issue: 1-2
  • Year: 2011
  • Summary: We assessed the effect of biochar incorporation into the soil on the soil-atmosphere exchange of the greenhouse gases (GHG) from an intensive subtropical pasture. For this, we measured N2O, CH4 and CO2 emissions with high temporal resolution from April to June 2009 in an existing factorial experiment where cattle feedlot biochar had been applied at 10 t ha−1 in November 2006. Over the whole measurement period, significant emissions of N2O and CO2 were observed, whereas a net uptake of CH4 was measured. N2O emissions were found to be highly episodic with one major emission pulse (up to 502 μg N2O-N m−2 h−1) following heavy rainfall. There was no significant difference in the net flux of GHGs from the biochar amended vs. the control plots. Our results demonstrate that intensively managed subtropical pastures on ferrosols in northern New South Wales of Australia can be a significant source of GHG. Our hypothesis that the application of biochar would lead to a reduction in emissions of GHG from soils was not supported in this field assessment. Additional studies with longer observation periods are needed to clarify the long term effect of biochar amendment on soil microbial processes and the emission of GHGs under field conditions.
  • Authors:
    • Chen, D.
    • Walker, C.
    • Pengthamkeerati, P.
    • Suter, H. C.
  • Source: Soil Research
  • Volume: 49
  • Issue: 4
  • Year: 2011