Association between collection site soil pH and chlorosis in Lupinus angustifolius induced by a fine-textured, alkaline soil

1993 ◽  
Vol 44 (8) ◽  
pp. 1821 ◽  
Author(s):  
WA Cowling ◽  
JC Clements

Collection site soil pH may be a useful predictor of tolerance in Lupznus angustifolzus to chlorosis induced by alkaline soils. We examined a range of genotypes from the Mediterranean region for their tolerance of an alkaline sandy clay loam (pH 8.8) from Merredin, Western Australia. Fifteen wild L. angustifolius lines, collected on a variety of soils that ranged in pH from 4.2 to 9.0, were compared with cultivars of L. angustifolzus and known alkaline-tolerant (L. cosentinii) and alkaline-sensitive (L. luteus) lupin species. Five-week-old seedlings varied greatly in chlorosis on the alkaline soil, from almost no chlorosis (as in L. cosentinzi cv Erregulla) to severely chlorotic (L. angustifolius line MJS176 from Spain). No lines were chlorotic after acid amelioration of the soil. Chlorosis score in wild L. angustifolius was not significantly correlated with soil pH at the collection site and was not associated with a particular soil texture, but there was a significant correlation between altitude of collection sites and chlorosis scores. Chlorosis-sensitive lines were from higher altitudes, had lower root and shoot fresh weight, were lower in Fe, Mn and K and were higher in Zn, P, and S in new growth than resistant lines. Chlorosis-sensitive lines also had the largest increases in fresh weight of roots and shoots in response to soil acidification. Genotypes with better root growth and therefore lower chlorosis symptoms on alkaline soil did not necessarily have the strongest root growth on acid ameliorated soil. Soil pH at the collection site in the Mediterranean region was not a reliable predictor of chlorosis in L. angustifolius induced by an alkaline fine-textured soil in Western Australia, although significant variation in tolerance to this soil was found within the species.

2021 ◽  
Vol 97 (4) ◽  
Author(s):  
Lucas Dantas Lopes ◽  
Jingjie Hao ◽  
Daniel P Schachtman

ABSTRACT Soil pH is a major factor shaping bulk soil microbial communities. However, it is unclear whether the belowground microbial habitats shaped by plants (e.g. rhizosphere and root endosphere) are also affected by soil pH. We investigated this question by comparing the microbial communities associated with plants growing in neutral and strongly alkaline soils in the Sandhills, which is the largest sand dune complex in the northern hemisphere. Bulk soil, rhizosphere and root endosphere DNA were extracted from multiple plant species and analyzed using 16S rRNA amplicon sequencing. Results showed that rhizosphere, root endosphere and bulk soil microbiomes were different in the contrasting soil pH ranges. The strongest impact of plant species on the belowground microbiomes was in alkaline soils, suggesting a greater selective effect under alkali stress. Evaluation of soil chemical components showed that in addition to soil pH, cation exchange capacity also had a strong impact on shaping bulk soil microbial communities. This study extends our knowledge regarding the importance of pH to microbial ecology showing that root endosphere and rhizosphere microbial communities were also influenced by this soil component, and highlights the important role that plants play particularly in shaping the belowground microbiomes in alkaline soils.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7949 ◽  
Author(s):  
Chao Yang ◽  
Jingjing Li ◽  
Yingjun Zhang

Background Soil aggregate-size classes, structural units of soil, are the important factors regulating soil organic carbon (SOC) turnover. However, the processes of litter C mineralization and storage in different aggregates-size classes are poorly understood, especially in the highly alkaline soils of north China. Here, we ask how four different aggregate sizes influence rates of C release (Cr) and SOC storage (Cs) in response to three types of plant litter added to an un-grazed natural grassland. Methods Highly alkaline soil samples were separated into four dry aggregate classes of different sizes (2–4, 1–2, 0.25–1, and <0.25 mm). Three types of dry dead plant litter (leaf, stem, and all standing dead aboveground litter) of Leymus chinensis were added to each of the four aggregate class samples. Litter mass loss rate, Cr, and Cs were measured periodically during the 56-day incubation. Results The results showed that the mass loss in 1–2 mm aggregates was significantly greater than that in other size classes of soil aggregates on both day 28 and day 56. Macro-aggregates (1–2 mm) had the highest Cr of all treatments, whereas 0.25–1 mm aggregates had the lowest. In addition, a significant negative relationship was found between Cs/Cr and soil pH. After incubation for 28 and 56 days, the Cs was also highest in the 1–2 mm aggregates, which implied that the macro-aggregates had not only a higher CO2 release capacity, but also a greater litter C storage capacity than the micro-aggregates in the highly alkaline soils of north China.


2001 ◽  
Vol 52 (3) ◽  
pp. 367 ◽  
Author(s):  
R. Chapman ◽  
S. Asseng

Historical meteorological data were used to estimate the frequency and timing of false break events at 10 locations in the annual pasture and wheat producing area in the Mediterranean climatic region of Western Australia. The seasonal pattern of false breaks identified by this analysis was compared with the dynamics of dormancy release in a field population of subterranean clover (Trifolium subterraneum L.) to determine the influence that these events may have on the legume content of annual pasture communities in this region. False break events were estimated to occur on approximately 2 of every 3 years (611–72% of years) with no significant differences across the area investigated. Changes in the risk of false break events were examined over discrete time periods. The period of greatest risk was predicted to occur during early autumn (early March to mid April). Seed softening is virtually complete in subterranean clover at this point. The seed bank strategy of this species is, therefore, not well adapted to withstand the effects of false breaks. This might largely explain the poor persistence of subterranean clover in the annual pasture communities in the Mediterranean region of Western Australia. The legume content of these pastures might be improved by selecting species with late dormancy release strategies that will give better protection from false breaks.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1060B-1060
Author(s):  
Amy N. Wright ◽  
Robert D. Wright ◽  
Brian E. Jackson ◽  
Jake A. Browder

Rhizosphere pH preferences vary for species and can dramatically influence root growth rates. Research was conducted to determine the effect of root zone pH on the root growth of BuxusmicrophyllaSieb. & Zucc. `Green Beauty' (boxwood) and KalmialatifoliaL. `Olympic Wedding' (mountain laurel). Boxwood plants removed from 3.8-L containers and mountain laurel plants removed from 19-L containers were situated in the center of separate Horhizotrons™. The key design feature of the Horhizotron is four wedge-shaped quadrants (filled with substrate) that extend away from the root ball. Each quadrant is constructed from glass panes that allow the measurement of roots along the glass as they grow out from the root ball into the substrate. For this experiment, each quadrant surrounding a plant was filled with a pine bark substrate amended per m3 (yd3) with 0.9 kg Micromax (Scotts-Sierra, Marysville, Ohio) and 0, 1.2, 2.4, or 3.6 kg dolomitic limestone. All plants received 50 g of 15N–3.9P–9.8K Osmocote Plus (Scotts-Sierra), distributed evenly over the surface of the root ball and all quadrants. Plants were grown from May to Aug. 2003 in a greenhouse. Root lengths were measured about once per week throughout the experiment. Root length increased linearly over time for all species in all substrates. Rate of root growth of boxwood was highest in pine bark amended with 3.6 kg·m3 lime and lowest in unamended pine bark. Rate of root growth of mountain laurel was lowest in pine bark amended with 3.6 kg·m3 lime. Results support the preference of mountain laurel and boxwood for acidic and alkaline soil pH environments, respectively.


1999 ◽  
Vol 39 (4) ◽  
pp. 457 ◽  
Author(s):  
C. Tang ◽  
N. C. Turner

A glasshouse experiment examined the effect of water stress on the growth of Lupinus angustifolius L. and Lupinus pilosus Murr. grown on an acid sandy soil, a limed sandy soil and an alkaline clay soil. Decreasing soil water content decreased the stomatal conductance and photosynthetic rate, and reduced plant growth. The responses of both species to water stress were generally similar in the sand and limed soils, but in the alkaline soil, L. angustifolius grown with limited water had markedly lower conductances and photosynthetic rates than the plants in the other soils at equivalent soil water contents. In adequately watered plants, the lupin species differed substantially in their growth response to soil types. Whereas the growth of L. pilosus was unaffected, the shoot dry weight of L. angustifolius grown on the limed and alkaline soils for 25–44 days was reduced by 32–54 and 44–86%, respectively, compared with the growth in the acid soil. The poor growth of L. angustifolius appeared to be primarily due to its poor root growth. In the alkaline soil, water stress reduced rather than stimulated root growth. The results suggest that, in the field, the limited root growth of L. angustifolius on alkaline soils will exacerbate water deficits when the topsoil dries out in the latter part of the season.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 756B-756
Author(s):  
M. Tagliavini ◽  
A.D. Rombolà ◽  
B. Marangoni

Pear rootstocks differ in tolerance to calcareous and alkaline soils. Roots of Fe-efficient dicots react to Fe-deficiency stress by strongly enhancing the Fe3+-reductase system, termed turbo-reductase, and by lowering the rhizosphere pH. In this study, we tested whether such adaptation mechanisms characterize pear and quince genotypes. Two trials were performed using micropropagated plants of three quince rootstocks (BA29, CTS212, and MC), three Pyrus communis rootstocks (OH × F51 and two selections obtained at Bologna Univ.: A28 and B21) and of two pear cultivars (Abbé Fétel and Bartlett, own-rooted). In the first trial, plants were grown in a nutrient solution with [Fe(+)] and without iron [Fe(–)] for 50 days. Their root iron-reducing capacity (IRC) was determined colorimetrically, using ferrozine and Fe-EDTA, and Fe uptake of Fe(+) plants was estimated. In the second trial, the rhizosphere pH of plants grown in an alkaline soil (pH in water = 8.3) was measured by a microelectrode. With the only exception of pears OH × F51 and A28, whose IRC was similar in Fe(+) and Fe(–) plants, the Fe-deficiency stress caused a significant decrease of the IRC. Among the Fe(–) plants, the two pear OH × F51 and A28 had higher IRC than the quince rootstocks and the cultivar Abbé F. When plants were pretreated with Fe, IRC was highest in the P. communis rootstocks (more than 50 nmol Fe2+/g fresh weight per h), intermediate in the own-rooted cultivars, and lowest in the quinces (<15 nmol Fe2+/g fresh weight per h). Fe uptake proved to be linearly and positively correlated with root Fe-reducing capacity (r = 0.91***). Rhizosphere pH, averaged over the first 2 cm from root tips, was highest in quince MC (7.2), intermediate in the other two quinces and in the cultivar Abbé F. (6.2–6.6) and lowest in the pear rootstocks and in the cultivar Bartlett (5.2–5.5). The results indicate that roots of pear and quinces do not increase their ability to reduce the iron under Fe-deficiency stress. The genotypical differential tolerance to iron chlorosis likely reflects differences in the standard reductase system and in the capacity of lowering the pH at soil/root interface. The determination of the root IRC appears very promising as a screening technique for selecting efficient Fe-uptake rootstocks.


2020 ◽  
Author(s):  
Eito Nonomura ◽  
Soh Sugihara ◽  
Mayuko Seki ◽  
Hidetoshi Miyazaki ◽  
Muniandi Jegadeesan ◽  
...  

&lt;p&gt;An understanding of the mechanisms of soil organic carbon (SOC) stabilization is essential to develop the appropriate management for C sequestration and soil health. In southern India, where neutral-alkaline soils are mainly distributed, soil C stocks are inherently low in cropland, despite relatively high clay contents (Clay&gt;ca. 30%, OC&lt;ca. 5 g C kg&lt;sup&gt;-1&lt;/sup&gt; soil). To consider this reason of low SOC in this area, we evaluated the fractionated C contents and its controlling factors, by measuring the particulate organic matter (POM). The objective of this study was to evaluate the effect of land management on the amount and composition of each fraction of soil in southern India. We collected the surface soils (0-10 cm) from two representative sites of southern India; Vertisols with alkaline soil pH (8.4-8.8) and Alfisols with neutral soil pH (6.0-7.0). At each site, two different land management were selected; forest and cropland of Vertisols, and cropland with no organic matter application (no-OM) and with manure application (with-OM) of Alfisols. Soils were separated into the four fractions; (1) Light Fraction; LF (&lt;1.7 g cm&lt;sup&gt;-3&lt;/sup&gt;) , (2) Coarse POM; cPOM (&gt;1.7 g cm&lt;sup&gt;-3&lt;/sup&gt;, 250-2000 &amp;#181;m), (3) Fine POM; fPOM(&gt;1.7 g cm&lt;sup&gt;-3&lt;/sup&gt;, 53-250 &amp;#181;m), and (4) Silt+Clay; S+C (&gt;1.7 g cm&lt;sup&gt;-3&lt;/sup&gt;, &lt;53 &amp;#181;m). Each fraction was analyzed by elemental analysis (C, N) and CPMAS &lt;sup&gt;13&lt;/sup&gt;C NMR spectroscopy. In Vertisols, C contents of cPOM, fPOM, S+C were significantly higher in forest (0.65, 0.91, 4.8 g kg&lt;sup&gt;-1&lt;/sup&gt; soil, respectively) than those of cropland (0.17, 0.22, 4.1 g kg&lt;sup&gt;-1&lt;/sup&gt; soil, respectively), causing the higher total SOC in forest (7.8 g kg&lt;sup&gt;-1&lt;/sup&gt; soil) than in cropland (4.5 g kg&lt;sup&gt;-1&lt;/sup&gt; soil). C concentration of cPOM, fPOM, and S+C fractions were also significantly higher in forest (3.7, 7.6, 6.7 g kg&lt;sup&gt;-1&lt;/sup&gt; fraction, respectively) than those of cropland (1.0, 2.7, 5.4 g kg&lt;sup&gt;-1&lt;/sup&gt; fraction, respectively). In particular, increasing rates in cPOM and fPOM (180-280 %) were greater than S+C (24 %), possibly suggesting that forest management should increase the relatively active and intermediate SOC pools through the C accumulation in cPOM and fPOM fractions of Vertisols. In Alfisols, C contents in LF and S+C were significantly higher in with-OM (1.1 and 5.2 g kg&lt;sup&gt;-1&lt;/sup&gt; soil, respectively) than in no-OM (0.76 and 4.7 g kg&lt;sup&gt;-1&lt;/sup&gt; soil, respectively). C concentration of S+C fraction was significantly higher in with-OM (14 g kg&lt;sup&gt;-1&lt;/sup&gt; fraction) than in no-OM (11 g kg&lt;sup&gt;-1&lt;/sup&gt; fraction), but not of cPOM and fPOM fractions. It suggests that the OM application to cropland should increase the slow SOC pool through the C accumulation in S+C fractions of Alfisols. These results indicate that different fraction may contribute to SOC stabilization between Vertisols and Alfisols in southern India.&lt;/p&gt;


2012 ◽  
Vol 38 (2) ◽  
pp. 53-66 ◽  
Author(s):  
Christian Perennou ◽  
Coralie Beltrame ◽  
Anis Guelmami ◽  
Pere Tomàs Vives ◽  
Pierre Caessteker

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