The effect of soil compaction on growth and P uptake by Trifolium subterraneum: interactions with mycorrhizal colonisation

The effects of vesicular-arbuscular mycorrhizal (VAM) colonisation on phosphorus (P) uptake and growth of clover (Trifolium subterraneum L.) in response to soil compaction were studied in three pot experiments. P uptake and growth of the plants decreased as the bulk density of the soil increased from 1.0 to 1.6 Mg m-3. The strongest effects of soil compaction on P uptake and plant growth were observed at the highest P application (60 mg kg-1 soil). The main observation of this study was that at low P application (15 mg kg-1 soil), P uptake and shoot dry weight of the plants colonised by Glomus intraradices were greater than those of non-mycorrhizal plants at similar levels of compaction of the soil. However, the mycorrhizal growth response decreased proportionately as soil compaction was increased. Decreased total P uptake and shoot dry weight of mycorrhizal clover in compacted soil were attributed to the reduction in the root length. Soil compaction had no significant effect on the percentage of root length colonised. However, total root length colonised was lower (6.6 m pot-1) in highly compacted soil than in slightly compacted soil (27.8 m pot-1). The oxygen content of the soil atmosphere measured shortly before the plants were harvested varied from 0.18 m3m-3 in slightly compacted soil (1.0 Mg m-3) to 0.10 m3m-3 in highly compacted soil (1.6 Mg m-3).

[1]  R. Dowdy,et al.  Effects of Applied Mechanical Stress on Plant Growth and Nutrient Uptake1 , 1982 .

[2]  T. V. John.  ROOT SIZE, ROOT HAIRS AND MYCORRHIZAL INFECTION: A RE-EXAMINATION OF BAYLIS'S HYPOTHESIS WITH TROPICAL TREES , 1980 .

[3]  H. So,et al.  Effects of soil bulk density and water regimen on root growth and uptake of phosphorus by ryegrass , 1984 .

[4]  S. A. Barber,et al.  Soil Nutrient Bioavailability: A Mechanistic Approach , 1984 .

[5]  L. Abbott,et al.  FORMATION OF EXTERNAL HYPHAE IN SOIL BY , 1985 .

[6]  A. R. Dexter,et al.  Penetration of very strong soils by seedling roots of different plant species , 1991, Plant and Soil.

[7]  W. Hanson.  The photometric determination of phosphorus in fertilizers using the phosphovanado‐molybdate complex , 1950 .

[8]  D. Sylvia.  Quantification of external hyphae of vesicular-arbuscular mycorrhizal fungi , 1992 .

[9]  V. Gianinazzi-Pearson,et al.  Physiological Interactions Between Symbionts in Vesicular-Arbuscular Mycorrhizal Plants , 1988 .

[10]  B. J. Atwell,et al.  Physiological responses of lupin roots to soil compaction , 1988, Plant and Soil.

[11]  C. Mullins,et al.  Effect of mechanical impedance on root growth and morphology of two varieties of pea (Pisum sativum L.) , 1994 .

[12]  P. Tinker,et al.  TRANSLOCATION AND TRANSFER OF NUTRIENTS IN VESICULAR‐ARBUSCULAR MYCORRHIZAS , 1978 .

[13]  L. Abbott,et al.  THE EFFECT OF PHOSPHORUS ON THE FORMATION OF HYPHAE IN SOIL BY THEVESICULAR‐ARBUSCULAR MYCORRHIZAL FUNGUS, GLOMUS FASCICULATUM , 1984 .

[14]  A. G. Bengough,et al.  Mechanical impedance to root growth: a review of experimental techniques and root growth responses , 1990 .

[15]  W. E. Larson,et al.  Soil Strength and Aeration Effects on Root Elongation1 , 1975 .

[16]  K. Barley,et al.  The Effects of Mechanical Stress on the Growth of Roots , 1962 .

[17]  A. Smucker,et al.  Tillage Modifications of Dry Edible Bean Root Colonization by VAM Fungi1 , 1985 .

[18]  S. A. Barber,et al.  Soybean Root Morphology and K Uptake1 , 1981 .

[19]  J. Tisdall.  Fungal hyphae and structural stability of soil , 1991 .

[20]  J. Sutton,et al.  Ecology of Endogone in Lake Huron sand dunes , 1975 .

[21]  L. Abbott,et al.  FORMATION OF EXTERNAL HYPHAE IN SOIL BY FOUR SPECIES OF VESICULAR‐ARBUSCULAR MYCORRHIZAL FUNGI , 1985 .

[22]  A. M. Alston,et al.  Effect of soil compaction on root growth and uptake of phosphorus , 1984, Plant and Soil.

[23]  S. Saif.  The influence of soil aeration on the efficiency of vesicular-arbuscular mycorrhizas. II. Effect of soil oxygen on growth and mineral uptake in Eupatorium odoratum L., Sorghum bicolor (L.) Moench and Guizotia abyssinica (L.f.) Cass. inoculated with vesicular-arbuscular mycorrhizal fungi. , 1983 .

[24]  S. Smith,et al.  Growth response and phosphorus uptake of rye with long and short root hairs: Interactions with mycorrhizal infection , 1994, Plant and Soil.

[25]  S. Gianinazzi,et al.  The physiology of vesicular-arbuscular mycorrhizal roots , 1983, Plant and Soil.

[26]  H. M. Taylor,et al.  ROOT ELONGATION RATES OF COTTON AND PEANUTS AS A FUNCTION OF SOIL STRENGTH AND SOIL WATER CONTENT , 1969 .

[27]  J. M. Phillips,et al.  Improved procedures for clearing roots and staining parasitic and vesicular-arbuscular mycorrhizal fungi for rapid assessment of infection. , 1970 .

[28]  F. A. Smith,et al.  MYCORRHIZAL INFECTION AND GROWTH OF TRIFOLIUM SUBTERRANEUM: USE OF STERILIZED SOIL AS A CONTROL TREATMENT , 1981 .

[29]  Manuela Giovannetti,et al.  AN EVALUATION OF TECHNIQUES FOR MEASURING VESICULAR ARBUSCULAR MYCORRHIZAL INFECTION IN ROOTS , 1980 .

[30]  M. Tester,et al.  The development of mycorrhizal infection in cucumber: effects of P supply on root growth, formation of entry points and growth of infection units , 1994 .

[31]  Sally E. Smith,et al.  MYCORRHIZAS OF AUTOTROPHIC HIGHER PLANTS , 1980 .

[32]  J. Colwell.  The estimation of the phosphorus fertilizer requirements of wheat in southern New South Wales by soil analysis , 1963 .

[33]  G. Safir,et al.  Increased drought tolerance of mycorrhizal onion plants caused by improved phosphorus nutrition , 1982, Planta.

[34]  P. Tinker,et al.  Phosphate flow into mycorrhizal roots , 1973 .

[35]  Corn Phosphorus and Potassium Uptake in Response to Soil Compaction , 1992 .