Microbial consortium inoculant increases pasture grasses yield in low‐phosphorus soil by influencing root morphology, rhizosphere carboxylate exudation and mycorrhizal colonisation

2021 ◽  
Author(s):  
Sangay Tshewang ◽  
Zed Rengel ◽  
Kadambot H. M. Siddique ◽  
Zakaria M. Solaiman
Keyword(s):  
Root Morphology ◽  
Microbial Consortium ◽  
Pasture Grasses ◽  
Low Phosphorus ◽  
Mycorrhizal Colonisation ◽  
Carboxylate Exudation

scholarly journals Growth, Rhizosphere Carboxylate Exudation, and Arbuscular Mycorrhizal Colonisation in Temperate Perennial Pasture Grasses Varied with Phosphorus Application

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2017
Author(s):  
Sangay Tshewang ◽  
Zed Rengel ◽  
Kadambot H. M. Siddique ◽  
Zakaria M. Solaiman
Keyword(s):  
Specific Root Length ◽  
Arbuscular Mycorrhizal ◽  
Differential Growth ◽  
Pasture Production ◽  
Tall Wheatgrass ◽  
Pasture Grasses ◽  
Mycorrhizal Colonisation ◽  
Phosphorus Application ◽  
Carboxylate Exudation ◽  
P Supply

Phosphorus (P) fertiliser is applied regularly to the nutrient-poor sandy soils in southwestern Australia to elevate and/or maintain pasture production. This study aimed to characterise differential growth, root carboxylate exudation, and mycorrhizal responses in three temperate perennial pasture grasses at variable P supply. Tall fescue (Festuca arundinacea L. cv. Prosper), veldt grass (Ehrharta calycina Sm. cv. Mission), and tall wheatgrass (Thinopyrum ponticum L. cv. Dundas) with five P rates varying from 0 to 100 mg P kg−1 soil were evaluated in a controlled environment. Rhizosphere carboxylate exudation and mycorrhizal colonisation were assessed. Veldt grass produced the maximum shoot dry weight, highest agronomic phosphorus-use efficiency at low P supply, as well as the highest specific root length and shoot P content at all P rates. Across species, the maximum shoot weight was obtained at 20 and 50 mg P kg−1 soil, which differed significantly from the two lowest P rates (0 and 5 mg P kg−1 soil). Phosphorus application influenced carboxylate exudation, with plants exuding acetate only in the zero P treatment, and citrate and malonate in the P-supplemented treatments. In all three species, acetate and malonate were the major carboxylates exuded (37–51% of the total). Only tall wheatgrass released trans-aconitate. Citrate and malonate concentrations in the rhizosphere increased with P supply, suggesting their important role in P acquisition. Phosphorus applications reduced arbuscular mycorrhizal colonisation and increased root diameter as the P rate increased. Root carboxylate exudation in low-P soil played a role in mobilisation of P via P solubilisation, but the role of exuded carboxylate in soils well supplied with P might be diminished.

scholarly journals Nitrogen and Potassium Fertilisation Influences Growth, Rhizosphere Carboxylate Exudation and Mycorrhizal Colonisation in Temperate Perennial Pasture Grasses

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1878
Author(s):  
Sangay Tshewang ◽  
Zed Rengel ◽  
Kadambot H. M. Siddique ◽  
Zakaria M. Solaiman
Keyword(s):  
Sandy Soil ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Dry Weight ◽  
Mycorrhizal Symbiosis ◽  
Shoot Dry Weight ◽  
Pasture Grasses ◽  
Mycorrhizal Colonisation ◽  
Low K ◽  
Carboxylate Exudation

Optimisation of potassium (K) use efficiency in pastures on sandy soil is challenging. We characterised growth response, root carboxylate exudation and mycorrhizal colonisation in three perennial pasture grasses: tall fescue (Festuca arundinacea L.), veldt grass (Ehrharta calycina Sm.) and tall wheatgrass (Thinopyrum ponticum L.) in two glasshouse experiments with: (1) four K rates (0, 40, 80 and 120 mg K kg-1 soil), and (2) four N and K treatments (no N and K (–N–K), 81 mg N kg-1 soil but no K, 80 mg K kg-1 soil but no N, and N at 81 and K at 80 mg kg-1 soil (+N+K)) in low-K sandy soil. Veldt grass had the highest shoot dry weight and shoot P content, but the lowest mycorrhizal colonisation. Potassium fertilisation had no significant impact on exudation of citrate and oxalate. The K0 plants had significantly lower exudation of acetate and total carboxylates than K40 plants. The +N+K plants had maximum shoot growth at both harvests (30 and 60 days after sowing (DAS)) and highest N and K shoot contents at 60 DAS. The –N–K plants exuded maximum amounts of citrate and malate at 30 DAS, but at 60 DAS tall fescue had the highest rhizosphere concentrations of citrate and malate in the +N+K treatment. At 60 DAS, mycorrhizal colonisation was significantly lower with than without N and K fertilisation. We concluded that pasture grasses could yield well even in inherently low-K soil without external K fertilisation and mycorrhizal symbiosis. However, the +N+K plants had the highest yield and root carboxylate exudation.

scholarly journals Contrasting responses of root morphology and root-exuded organic acids to low phosphorus availability in three important food crops with divergent root traits

AoB Plants ◽  
2015 ◽  
Vol 7 ◽  
pp. plv097 ◽  
Author(s):  
Yan-Liang Wang ◽  
Marit Almvik ◽  
Nicholas Clarke ◽  
Susanne Eich-Greatorex ◽  
Anne Falk Øgaard ◽  
...  
Keyword(s):  
Organic Acids ◽  
Root Morphology ◽  
Root Traits ◽  
Phosphorus Availability ◽  
Food Crops ◽  
Important Food ◽  
Low Phosphorus

GENOTYPIC DIFFERENCES IN ROOT MORPHOLOGY AND PHOSPHORUS UPTAKE KINETICS INBRASSICA NAPUSUNDER LOW PHOSPHORUS SUPPLY

2010 ◽  
Vol 33 (6) ◽  
pp. 889-901 ◽  
Author(s):  
Yifan Hu ◽  
Xiangsheng Ye ◽  
Lei Shi ◽  
Haiyan Duan ◽  
Fangsen Xu
Keyword(s):  
Root Morphology ◽  
Phosphorus Uptake ◽  
Uptake Kinetics ◽  
Genotypic Differences ◽  
Low Phosphorus

Intrinsic root morphology determines the phosphorus acquisition efficiency of five annual pasture legumes irrespective of mycorrhizal colonisation

2021 ◽  
Vol 48 (2) ◽  
pp. 156
Author(s):  
Jonathan W. McLachlan ◽  
Adeline Becquer ◽  
Rebecca E. Haling ◽  
Richard J. Simpson ◽  
Richard J. Flavel ◽  
...  
Keyword(s):  
Root Morphology ◽  
Mycorrhizal Fungi ◽  
Maximum Yield ◽  
Stress Index ◽  
Symbiotic Associations ◽  
P Acquisition ◽  
Pasture Legumes ◽  
Mycorrhizal Association ◽  
Mycorrhizal Colonisation ◽  
The Impact

Mycorrhizal fungi are ubiquitous in agroecosystems and form symbiotic associations that contribute to the phosphorus (P) acquisition of many plants. The impact of mycorrhizas is most pronounced in P-deficient soil and commonly involves modifications to the root morphology of colonised plants. However, the consequences of mycorrhizal colonisation on root acclimation responses to P stress are not well described. Five annual pasture legumes, with differing root morphologies, were grown to determine the effect of mycorrhizal colonisation on shoot yield, root morphology and P uptake. Micro-swards of each legume were established in pots filled with a topsoil layer that had been amended with five rates of P fertiliser. The topsoil overlaid a low-P subsoil that mimicked the stratification of P that occurs under pasture. Mycorrhizal colonisation improved P acquisition and shoot yield in the low-P soil treatments, but did not reduce the critical external P requirement of the legumes for near-maximum yield. The yield responses of the mycorrhizal plants were associated with reduced dry matter allocation to topsoil roots, which meant that the P acquisition benefit associated with mycorrhizal colonisation was not additive in the P-deficient soil. The contribution of the mycorrhizal association to P acquisition was consistent among the legumes when they were compared at an equivalent level of plant P stress, and was most pronounced below a P stress index of ~0.5. The intrinsic root morphology of the legumes determined their differences in P-acquisition efficiency irrespective of mycorrhizal colonisation.

Sign in / Sign up

Export Citation Format

Share Document