
TY  - JOUR
A1  - Kelly, R. M. 
A1  - Edwards, D. G. 
A1  - Thompson, J. P. 
A1  - Magarey, R. C. 
T1  - Responses of sugarcane, maize, and soybean to phosphorus and vesicular-arbuscular mycorrhizal fungi
JF  - Australian Journal of Agricultural Research
JO  - Aust. J.  Agric. Res.
Y1  - 2001
VL  - 52
IS  - 7
SP  - 731
EP  - 743
KW  - mycorrhizal dependency, responsiveness, yield decline, critical P concentration.
UR  - https://doi.org/10.1071/AR00131 
N2  - The presence of vesicular-arbuscular mycorrhizal (VAM) fungi in long-term cane-growing fields associated with yield decline led to the supposition that VAM fungi may be responsible for the poor yields. A glasshouse trial was established to test the effectiveness of a species of VAM fungi, Glomus clarum, extracted from one of these North Queensland fields on the growth of sugarcane (Saccharum interspecific hybrid), maize (Zea mays), and soybean (Glycine max) for 6 phosphorus (P) rates (0, 2.7, 8.2, 25, 74, 222 mg/kg). For maize and soybean plants that received VAM (+VAM), root colonisation was associated with enhanced P uptake, improved dry weight (DW) production, and higher index tissue-P concentrations than those without VAM (&#8211;VAM). By comparing DW responses of maize and soybean for different P rates, savings in fertiliser P of up to 160 and 213 kg/ha, respectively, were realised. Sugarcane plants were generally less responsive. Apart from a 30% DW increase with VAM when 2.7 mg P/kg was added, DW of +VAM plants was equivalent to, or worse than in the case of 222 mg P/kg, DW of &#8211;VAM plants. For all 3 host species, colonisation was least at the highest P application, presumably from excessive P within the plant tissue. Critical P concentrations for the 3 host species were below those reported elsewhere, and for soybean and sugarcane, the critical concentration for +VAM plants was lower than that of &#8211;VAM plants. There are 3 implications that arise from this study. First, VAM fungi present in cane-growing soils can promote the growth of maize and soybean, which are potential rotation crops, over a range of P levels. Second, the mycorrhizal strain taken from this site did not generally contribute to a yield decline in sugarcane plants. Third, application of P fertiliser is not necessary for sugarcane when acid-extractable P is &#60;30 mg/kg if sufficient VAM propagules are present, or mp;lt;47 mg/kg if a mycorrhizal response is not anticipated. 
ER  -

