Influence of vesicular-arbuscular mycorrhiza fungi on growth and uptake of various nutrients as well as uptake ratio of fertilizer P for lucerne (Medicago sativa)

Abstract

Lucerne plants were inoculated with the vesicular-arbuscular mycorrhizal (VAM) fungus, Glomus caledonius and Rhizobium meliloti and grown in pots in voli~re. Treatments were 0, 1 and 2mg P added to 100g of a soil with low P-fertility. Plants were harvested after 6, 9, 13 and 18 weeks, allowing shoots to regrow between harvests. VAM-infection was determined after 6 and 18 weeks, dry weight, concentration and uptake of P and concentrations of N, K, Ca, Mg, Cu and Zn were determined at all harvests.VAM-inoculation increased growth of shoots, P-concentration and P-uptake at all soil-P levels and the increase was most pronounced at the lowest soil-P level. P-fertilization also increased growth, P-concentration and P-uptake. VAM-inoculation showed tendency to increase N-and K-uptake and decreased Ca-, Mg-and Zn-concentrations in shoots. The uptake ratio of fertilizer-P was increased by VAM~

Direct and indirect effects of VA mycorrhizal fungi and rhizosphere microorganisms on acquisition of mineral nutrients by maize (Zea mays L.) in a calcareous soil

“…In case of decrease, the results have been mostly discussed in terms of dilution effects because of the large differences in plant size (dry weight) in mycorrhizal and non-mycorrhizal treatments. But in many instances, even though the concentration decreased, the results could not be fully explained with a dilution effect (Lambert et al, 1979;Nielsen & Jensen, 1983). On the other hand, the causes of increased concentration are seldom discussed (Buttery et al, 1988;Lu & Miller, 1989).…”

The role of arbuscular mycorrhiza in zinc uptake by red clover growing in a calcareous soil spiked with various quantities of zinc

“…On the other hand, under conditions of high available soil Zn and Cu, the concentrations of these trace elements in shoots have been reported to be lower in mycorrhizal than in non-mycorrhizal plants (Dueck et al, 1986;Leyval et al, 1991;Liu et al, 2000). Reduced concentrations of micronutrients in mycorrhizal plants are sometimes attributed to a dilution effect linked to an increase in plant dry matter (DM) yield (Nielsen and Jensen, 1983). However, experimental results cannot always be explained by a dilution effect.…”

Effects of EDTA application and arbuscular mycorrhizal colonization on growth and zinc uptake by maize (Zea mays L.) in soil experimentally contaminated with zinc

“…On the other hand, when excessive concentrations of trace metals are present in soils, mycorrhizal plants can contain lower shoot metal concentrations than uninoculated plants growing under similar conditions (Dueck et al, 1986;Leyval et al, 1991;Liu et al, 2000;Tao, 1997). The lower metal concentrations in mycorrhizal plants has often been attributed to larger plant biomass with a resultant 'growth dilution' effect (Nielsen and Jensen, 1983). However, dilution effects cannot explain all the experimental results.…”