Effects of Drought on Growth and Competitive Ability of Perennial Ryegrass and White Clover

Abstract

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Effects of soil moisture and plant interactions on the soil microbial community structure

“…In agreement with other studies [19,23,31], increasing soil moisture improved the growth of both white clover and ryegrass. The plant biomass of ryegrass was greater than that of white clover and the effect of increasing soil moisture on growth was more pronounced in ryegrass than in clover.…”

“…Burch and Johns [8] had observed that white clover grown in competition with Festuca had poorer control of leaf transpiration than Festuca, which led to lower leaf water potentials and increased leaf senescence. Grasses have been reported to have better control of stomata and higher leaf water potential, which increases growth under drought stress [20,31]. This may also be related to the greater root production of ryegrass compared to clover, which would have led to a greater soil volume available for water uptake to the ryegrass.…”

Effects of an extended drought period on physiological properties of grassland species in the field

“…In 2006, the higher leaf water potentials (W p and W m ) of R. obtusifolius compared to the grass species support this hypothesis. T. repens is well known to be sensitive and less tolerant to drought than several other perennial species when grown in pasture mixture due to its shallow, less extensive root system and earlier leaf senescence (Whitehead 1983;Thomas 1984;Guobin and Kemp 1992;Brink and Pederson 1998). However, the capacity of T. repens to reach water from deeper soil reserves than co-occurring some other species has also been reported (Johns and Lazenby 1973;Guckert et al 1993), especially when grown together with Lolium perenne (Grieu et al 2001).…”

WATER STRESS MODIFIES INTRASPECIFIC INTERFERENCE BETWEEN RUST (PUCCINIA LAGENOPHORAE COOKE)‐INFECTED AND HEALTHY GROUNDSEL (SENECIO VULGARIS L.)

“…Limited excavations showed that roots from rusted as well as control monocultures had penetrated into wet soil deep in the profile but did not allow the quantity of roots from the two to be compared, nor roots from control and rusted plants in mixtures to be distinguished. In general, differences in the size of root systems (Thomas, 1984) and in gross root morphology (Martin & Snaydon, 1982) may be significant in competitive interactions in the field, and the morphology and spatial distributions of the root system of rusted plants under field conditions clearly merit further investigation. Correlations between growth and physiological parameters at final harvest require cautious interpretation.…”