Seasonal variation in the infectivity of VA mycorrhizal fungi in annual pastures in a Mediterranean environment

1987 ◽  
Vol 38 (4) ◽  
pp. 707 ◽  
Author(s):  
MA Scheltema ◽  
LK Abbott ◽  
AD Robson

The seasonal variation in the rate and extent of formation of mycorrhizas in pasture soils from two sites in south-west Australia was examined. Undisturbed soil cores were taken on eight occasions throughout the year, sown with Trifolium subterraneum L. and maintained in a glasshouse. At each collection time the extent of formation of mycorrhizas was measured 3 and 6 weeks after sowing.There was no seasonal variation in the extent of mycorrhizas formed in undisturbed soil cores at one site, hut at the other site the extent of mycorrhizas decreased over time. The rate of formation of mycorrhizas was most rapid when cores were collected immediately after the opening rains of the season.Similar species of fungi were present at both sites; however, the rate and extent of infection formed by each species differed between the sites. At both sites the infectivity of A. laevis and fine endophyte decreased throughout the winter months, but the infectivity of Glomus spp. did not change. Neither the total spore number nor an estimate of the number of infective propagules reflected the infectivity of the total population of VA mycorrhizal fungi measured simultaneously at the two sites.

Agronomie ◽  
2000 ◽  
Vol 20 (3) ◽  
pp. 297-307 ◽  
Author(s):  
Pierre Benoit ◽  
Enrique Barriuso ◽  
Philippe Vidon ◽  
Benoit Réal

1981 ◽  
Vol 59 (6) ◽  
pp. 1056-1060 ◽  
Author(s):  
Sharon L. Rose

Endemic plants of the Sonoran Desert of Baja California were sampled for mycorrhizal associations. Eight of the 10 plant species examined were colonized by vesicular–arbuscular (VA) mycorrhizal fungi. Soil sievings revealed chlamydospores of three VA mycorrhizal Glomus spp.; G. microcarpus, G. fasciculatus, and G. macrocarpus. At the time of sampling, the populations of VA fungal spores in the soil were low, with one to five chlamydospores per 100 g soil sample.


2018 ◽  
Vol 50 (1) ◽  
pp. 77-92 ◽  
Author(s):  
Kenneth Miller ◽  
Brenna J. Aegerter ◽  
Nicholas E. Clark ◽  
Michelle Leinfelder-Miles ◽  
Eugene M. Miyao ◽  
...  

1999 ◽  
Vol 63 (6) ◽  
pp. 1530-1543 ◽  
Author(s):  
Johan Perret ◽  
S. O. Prasher ◽  
A. Kantzas ◽  
C. Langford

Soil Research ◽  
2017 ◽  
Vol 55 (7) ◽  
pp. 682 ◽  
Author(s):  
D. Moret-Fernández ◽  
C. Peña-Sancho ◽  
B. Latorre ◽  
Y. Pueyo ◽  
M. V. López

Estimation of the soil–water retention curve, θ(h), on undisturbed soil samples is of paramount importance to characterise the hydraulic behaviour of soils. Although a method of determining parameters of the water retention curve (α, a scale parameter inversely proportional to mean pore diameter and n, a measure of pore size distribution) from saturated hydraulic conductivity (Ks), sorptivity (S) and the β parameter, using S and β calculated from the inverse analysis of upward infiltration (UI) has been satisfactorily applied to sieved soil samples, its applicability to undisturbed soils has not been tested. The aim of the present study was to show that the method can be applied to undisturbed soil cores representing a range of textures and structures. Undisturbed soil cores were collected using stainless steel cylinders (5cm internal diameter×5cm high) from structured soils located in two different places: (1) an agricultural loam soil under conventional, reduced and no tillage systems; and (2) a loam soil under grazed and ungrazed natural shrubland. The α and n values estimated for the different soils using the UI method were compared with those calculated using time domain reflectometry (TDR) pressure cells (PC) for pressure heads of –0.5, –1.5, –3, –5, –10 and –50kPa. To compare the two methods, α values measured with UI were calculated to the drying branch of θ(h). For each treatment, three replicates of UI and PC calculations were performed. The results showed that the 5-cm high cylinders used in all experiments provided accurate estimates of S and β. Overall, the α and n values estimated with UI were larger than those measured with PC. These differences could be attributed, in part, to limitations of the PC method. On average, the n values calculated from the optimised S and β data were 5% larger than those obtained with PC. A relationship with a slope close to 1 fitted the n values estimated using both methods (nPC=0.73 nUI+0.49; R2=0.78, P<0.05). The results show that the UI method is a promising technique to estimate the hydraulic properties of undisturbed soil samples.


Soil Science ◽  
2011 ◽  
Vol 176 (8) ◽  
pp. 399-406 ◽  
Author(s):  
Anders Lindblad Vendelboe ◽  
Per Moldrup ◽  
Goswin Heckrath ◽  
Yan Jin ◽  
Lis Wollesen de Jonge

2012 ◽  
Vol 11 (1) ◽  
Author(s):  
Andreas H. Kristensen ◽  
Chisato Hosoi ◽  
Kaj Henriksen ◽  
Per Loll ◽  
Per Moldrup

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