
TY  - JOUR
A1  - Riffkin, Penny A. 
A1  - Quigley, Paul E. 
A1  - Kearney, Gavin A. 
A1  - Cameron, Fiona J. 
A1  - Gault, Robert R. 
A1  - Peoples, Mark B. 
A1  - Thies, Janice E. 
T1  - Factors associated with biological nitrogen fixation in dairy pastures in south-western Victoria
JF  - Australian Journal of Agricultural Research
JO  - Aust. J.  Agric. Res.
Y1  - 1999
VL  - 50
IS  - 2
SP  - 261
EP  - 272
KW  - 15N natural abundance, nematodes, phosphorus, rhizobia, potassium, white clover, Rhizobium leguminosarum bv. trifolii, Trifolium repens, N fixation.
UR  - https://doi.org/10.1071/A98035 
N2  - A survey of 71 sites was conducted in the dairying districts of south-western Victoria in October 1994 to determine factors associated with nitrogen (N) fixation in white clover based pastures. Twenty-eight factors (environmental, microbiological, management, soil, and pasture) were considered in relation to 2 indicators of N fixation by white clover, %Ndfa (percentage of total plant N derived from the atmosphere, as determined by the 15N natural abundance method) and kg of N fixed per tonne herbage dry matter (legume and non-legume). On light-textured soils (sandy loams), soil potassium, rhizobia numbers, total soil N, and density of the nematode Pratylenchus sp. accounted for 72% of variation in %Ndfa. On medium-textured soils (clay loams), crude protein of perennial ryegrass and plant-available phosphorus in the soil accounted for 30% of variation in %Ndfa. The amount of N fixed was influenced by different factors, again depending on soil texture. Soil chemical properties accounted for 31% variation on the medium-textured soils with nematode density, pasture quality, and soil chemical properties accounting for 77% of variation on light-textured soils. Amounts of N fixed per tonne herbage dry matter produced averaged 8.2 kg on the light-textured soils and 7.3 kg on the medium-textured soils. Average %Ndfa values were 67% and 60% on light- and medium-textured soils, respectively. Effects of soil texture on N fixation were attributed to the different cation exchange and water-holding capacities of the soils and highlight the importance of considering soil type in N fixation studies. 
ER  -

