Leaf, stolon and root growth of white clover (Trifolium repens L.) in response to irrigation with saline water

Abstract

The effect of irrigation with water at salinity concentrations of 2.6 and 5.2 dS m -1 on the growth of pure swards of six cultivars of white clover (Trifolium repens L.) was examined over three irrigation seasons at Tatura, Victoria, Australia. After two irrigation seasons, soil EC e levels increased to 6 dS m -t at 0-60 cm depth in the higher salinity treatment resulting in highly significant (p<0.001) reductions in shoot dry matter production, flowering densities and petiole and stolon densities. These saline conditions also increased (p<0.001)concentrations of C1 and Na in the shoots and reduced (p<0.001) leaf water potentials and canopy photosynthetic efficiency rates especially at high temperatures. In contrast, root growth increased at shallow depths (0-15 cm) under both saline irrigation treatments (p<0.001). Cultivars differed significantly in salt tolerance (p < 0.001), with cultivars Haifa and Irrigation exhibiting superior tolerance in terms of lower reductions in herbage yield (p<0.05) and petiole densities (p<0.001) during one irrigation season and lower concentrations of Na and C1 in the shoots (p < 0.05) compared with the other four cultivars (Aran, Kopu, Pitau and Tamar). In addition, canopy photosynthetic efficiency rates (A*) in plots irrigated with water at 5.2 dS m -1 were higher in cultivar Haifa compared with cultivar Tamar (p<0.05). The salt tolerance ranking obtained for the six cultivars was in broad agreement with earlier greenhouse studies. Consequently, it appears that, while white clover is an extremely salt-sensitive species, it is possible to grow cultivars which display greater salt tolerance than other cultivars and which provide some scope to increase, or at least to maintain, pasture yields in areas where the soil salinity is low to mod-M. E. Rogers (t~) 9 C. L. Noble erate or where pumped saline groundwater is re-used for irrigation.

Chinese rose ( Rosa chinensis ) growth and ion accumulation under irrigation with waters of different salt contents

“…Rogers et al (1994) reported that concentrations of Na and Cl in the shoots of white clover linearly increased with increasing soil EC e levels above 1 dS/m, and values were negatively related to shoot dry matter production. In the present study, K/Na ratio in stems had a slightly greater positive correlation with stem dry mass than the corresponding correlation in roots (Fig.…”

“…Similar results were also found in other studies (Cai et al, 2014;Muhammad Jafar et al, 1991;Niu et al, 2013). The influence of salinity on flowers was higher than that on vegetative growth, indicating that reduced reproductive growth may have important implications for the persistence of vegetative growth under continued saline irrigation (Rogers et al, 1994). Therefore, control of vegetative growth by pruning may be an effective measure to ensure relatively high production of rose flowers under saline irrigation.…”

“…Salinity had severe detrimental effects on root growth and consequently affected water uptake, and finally the grain yield and water use efficiency (Grewal, 2010;Musacchi et al, 2006;Rogers et al, 1994). In the current study, the total root and fine root lengths decreased as salinity of irrigation water increased (Table 6), while coarse root length increased after an initial decrease ( Table 6)-indicating that fine roots were more susceptible to salt injury than coarse roots.…”

Forage Options for Dairy Farms with Reduced Water Availability in the Southern Murray Darling Basin of Australia

“…In a study comparing the WP, production and water use of three perennial forage legumes (white clover, red clover and lucerne), at three different irrigation intervals, Kelly et al [33] showed white clover to be more sensitive to variations in irrigation frequency than either red clover or lucerne. This was attributed to its relatively shallow root structure and density with most of its roots located in the top 20 cm of the soil profile [44][45][46] and therefore its inability to access soil water stored at depth. White clover was also shown to be the least tolerant to deficit irrigation of 15 forage species evaluated in a humid subtropical climate at Camden, NSW, which again was attributed to its root architecture and density [12,47].…”

Differential Responses to Salt Stress in Four White Clover Genotypes Associated With Root Growth, Endogenous Polyamines Metabolism, and Sodium/Potassium Accumulation and Transport

“…Increasing soil salinization yearly at a rate of 10% accelerates the demand for salt-tolerant crop germplasms to maintain agricultural yield worldwide ( Shrivastava and Kumar, 2015 ). For the evaluation of salt tolerance in white clover species, the study by Rogers et al (1994) found that cv. Haifa and cv.…”