Field inoculation with arbuscular-mycorrhizal fungi overcomes phosphorus and zinc deficiencies of linseed (Linum usitatissimum) in a vertisol subject to long-fallow disorder

• Published in: Plant and soil Vol. 371; no. 1/2; pp. 117 - 137
• Main Authors: Thompson, J. P., Clewett, T. G., Fiske, M. L.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.10.2013; Springer Netherlands; Springer Nature B.V
• Subjects: Agricultural practices; Agricultural site preparation; Agricultural soils; Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; Biological and medical sciences; Biomass; biomass production; Biomedical and Life Sciences; bolls; Colonization; conservation tillage; Crop yield; Cropping systems. Cultivation. Soil tillage; Diseases and pests; Ecology; Economic plant physiology; Environmental aspects; fallow; Fallowing; Fertilizers; field crops; field experimentation; Flax; Flaxseed; Fumigation; Fundamental and applied biological sciences. Psychology; fungi; General agronomy. Plant production; Generalities. Cropping systems and patterns; Glomus; growers; Growing season; Health aspects; Host-parasite relationships; Inoculation; inoculum; Life Sciences; linseed; Linum usitatissimum; Mycorrhizas; nutrition; phosphorus; Phosphorus content; Plant biomass; Plant growth; Plant Physiology; Plant Sciences; Plants; Regular Article; Roots; seed yield; Soil conservation; Soil fertility; Soil fungi; Soil inoculation; Soil microorganisms; Soil Science & Conservation; Soil water; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Soils; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...); Vertisols; Wheat; Zinc; Australia; Plant P and Zn inflows; Arbuscular mycorrhizal fungi; Soil fumigation; Linseed; ); Relative field mycorrhizal dependency; Plant P and Zn nutrition; Long-fallow disorder; Oilseed; Fumigation; Linseed (Linum usitatissimum); Inlet flow; Glomeromycota; Fiber crop; Fungi; Field; Linum usitatissimum; Vertisols; Inoculation; Linaceae; Dicotyledones; Angiospermae; Symbiosis; Nutrition; Cropping system; Phosphorus; Mineral soils; Symbiont; Zinc; Endomycorrhiza; Mycorrhiza; Spermatophyta; Soil plant relation; Fallow
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-013-1679-z

Background and aims Long-fallow disorder is expressed as exacerbated deficiencies of phosphorus (P) and/or zinc (Zn) in field crops growing after long periods of weed-free fallow. The hypothesis that arbuscular-mycorrhizal fungi (AMF) improve the P and Zn nutrition, and thereby biomass production and seed yield of linseed (Linum usitatissimum) was tested in a field experiment. Methods A factorial combination of treatments consisting of ± fumigation, ±AMF inoculation with Glomus spp., ±P and ±Zn fertilisers was used on a long-fallowed vertisol. The use of such methods allowed an absolute comparison of plants growing with and without AMF in the field for the first time in a soil disposed to long-fallow disorder. Results Plant biomass, height, P and Zn concentrations and contents, boll number and final seed yield were (a) least in fumigated soil with negligible AMF colonisation of the roots, (b) low initially in long-fallow soil but increased with time as AMF colonisation of the roots developed, and (c) greatest in soil inoculated with AMF cultures. The results showed for the first time in the field that inflows of both P and Zn into linseed roots were highly dependent on %AMF-colonisation (R²=0.95 for P and 0.85 for Zn, P<0.001) in a soil disposed to long-fallow disorder. Relative field mycorrhizal dependencies without and with P+Zn fertiliser were 85 % and 86 % for biomass and 68 % and 52 % for seed yield respectively. Conclusions This research showed in the field that AMF greatly improved the P and Zn nutrition, biomass production and seed yield of linseed growing in a soil disposed to long-fallow disorder. The level of mycorrhizal colonisation of plants suffering from long-fallow disorder can increase during the growing season resulting in improved plant growth and residual AMF inoculum in the soil, and thus it is important for growers to recognise the cause and not terminate a poor crop prematurely in order to sow another. Other positive management options to reduce long fallows and foster AMF include adoption of conservation till-age and opportunity cropping.