Responses of some crop plants to correction of subsoil acidity

1986 ◽  
Vol 26 (1) ◽  
pp. 107 ◽  
Author(s):  
A Pinkerton ◽  
JR Simpson
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Subterranean Clover ◽  
Soil Profiles ◽  
Crop Species ◽  
Subsoil Acidity ◽  
Crop Establishment ◽  
Soil Liming ◽  
Native Pasture ◽  
Reconstituted Soil

The effects of subsoil acidity and lime incorporation on plant growth were examined for several crop species (wheat, rape, lucerne and phalaris) growing in reconstituted soil profiles. The pH levels of the profiles had been differentially lowered because they had been under improved subterranean clover pastures for various periods up to 55 years. Acidities in the upper layers differed by at least one pH unit and the depth of the acidified horizons reached 60 cm in the most severely affected soil. All species showed good root growth in soil from 'unimproved' native pasture. Root growth was much poorer in the more acid profiles, particularly between 10- and 40-cm depths, where CaCl2-extractable aluminium was high (> 6 �g g-1). Liming throughout the profile reduced exchangeable aluminium (to about 1 �gg-1) and increased root lengths in the most acid profile by about 60% (0-40 cm depth), so that root lengths then approached those in the 'unimproved' soil. Liming increased shoot yields of all crops except phalaris. The increase was greatest for lucerne (400%), with smaller increases for wheat (39%) and rape (26%). Liming the surface horizon (0- 10 cm) had little effect on most species, but substantially improved root length and shoot yield of lucerne (75 and 300% respectively). The agronomic implications of these findings in crop establishment and drought resistance on acidified soils are discussed.

Interactions of surface drying and subsurface nutrients affecting plant growth on acidic soil profiles from an old pasture

1986 ◽  
Vol 26 (6) ◽  
pp. 681 ◽  
Author(s):  
A Pinkerton ◽  
JR Simpson
Keyword(s):  
Subsurface Layer ◽  
Acid Soils ◽  
Subterranean Clover ◽  
Soil Surface ◽  
Soil Profiles ◽  
Poor Growth ◽  
South Wales ◽  
Reconstituted Soil ◽  
Subsurface Layers ◽  
Surface Drying

Previous studies on soils from old pastures in southern New South Wales have demonstrated that nutrients have accumulated at the soil surface, but that the 40-100-mm depth layer in many profiles has become strongly acidic (e.g. pH 4.7), and high in extractable aluminium. Poor growth of subterranean clover has occurred on such soils during dry periods and may be associated with poor root growth in the acidic, nutrient-poor subsurface layers. Possible nutritional causes of these observations were investigated using reconstituted soil profiles. The root and shoot growth of subterranean clover, wheat, oats and lucerne were compared in unamended profiles and in profiles amended by applying nutrients or calcium carbonate (lime) to correct the more obvious deficiencies of the subsurface layers. Subterranean clover grew well as long as the surface soil remained moist, so that plants could utilise the nutrients potentially available within it. When the surface (0-40 mm) was allowed to dry but the subsurface layers remained moist, growth was poor unless phosphate was applied to the moist layer. Subsurface application of lime alone was ineffective. Nitrogen application increased clover growth in the presence of added phosphate or surface moisture, but nitrogen alone did little to alleviate the effects of surface drought. Wheat, and to a lesser extent oats, responded to subsurface lime when the surface was moist, and both responded to subsurface phosphate when the surface was dry. Lucerne responded to subsurface phosphate similarly to subterranean clover but the response was more than doubled in the presence of additional borate and lime. Lime without borate was not effective. When the surface was maintained moist, liming both the surface (0-40 mm) and subsurface layers improved the response over liming the subsurface layer only. The results suggest that declining fertility and productivity in old pastures developed on acid soils may not be rectified by liming alone, but that cultivation, ripping or drilling of phosphate, and in some cases addition of borate, may be required to improve the penetration of nutrients, particularly phosphorus, to greater depth.

Sink strength of citrus rootstocks under water deficit

2021 ◽  
Author(s):  
Simone F da Silva ◽  
Marcela T Miranda ◽  
Vladimir E Costa ◽  
Eduardo C Machado ◽  
Rafael V Ribeiro
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Water Deficit ◽  
Carbon Allocation ◽  
Sink Strength ◽  
Rangpur Lime ◽  
Carbon Supply ◽  
Valencia Orange ◽  
Source Sink ◽  
Orange Trees

Abstract Carbon allocation between source and sink organs determines plant growth and is influenced by environmental conditions. Under water deficit, plant growth is inhibited before photosynthesis and shoot growth tends to be more sensitive than root growth. However, the modulation of source-sink relationship by rootstocks remain unsolved in citrus trees under water deficit. Citrus plants grafted on Rangpur lime are drought tolerant, which may be related to a fine coordination of the source-sink relationship for maintaining root growth. Here, we followed 13C allocation and evaluated physiological responses and growth of Valencia orange trees grafted on three citrus rootstocks (Rangpur lime, Swingle citrumelo and Sunki mandarin) under water deficit. As compared to plants on Swingle and Sunki rootstocks, ones grafted on Rangpur lime showed higher stomatal sensitivity to the initial variation of water availability and less accumulation of non-structural carbohydrates in roots under water deficit. High 13C allocation found in Rangpur lime roots indicates this rootstock has high sink demand associated with high root growth under water deficit. Our data suggest that Rangpur lime rootstock used photoassimilates as sources of energy and carbon skeletons for growing under drought, which is likely related to increases in root respiration. Taken together, our data revealed that carbon supply by leaves and delivery to roots are critical for maintaining root growth and improving drought tolerance, with citrus rootstocks showing differential sink strength under water deficit.

scholarly journals Sewage sludge application enhances soil properties and rice growth in a salt-affected mudflat soil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuhua Shan ◽  
Min Lv ◽  
Wengang Zuo ◽  
Zehui Tang ◽  
Cheng Ding ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Organic Carbon ◽  
Plant Growth ◽  
Root Growth ◽  
Soil Fertility ◽  
Soil Properties ◽  
Soluble Sugar ◽  
Soil Reclamation ◽  
Rice Growth ◽  
Promote Plant Growth

AbstractThe most important measures for salt-affected mudflat soil reclamation are to reduce salinity and to increase soil organic carbon (OC) content and thus soil fertility. Salinity reduction is often accomplished through costly freshwater irrigation by special engineering measures. Whether fertility enhancement only through one-off application of a great amount of OC can improve soil properties and promote plant growth in salt-affected mudflat soil remains unclear. Therefore, the objective of our indoor pot experiment was to study the effects of OC amendment at 0, 0.5%, 1.0%, 1.5%, and 2.5%, calculated from carbon content, by one-off application of sewage sludge on soil properties, rice yield, and root growth in salt-affected mudflat soil under waterlogged conditions. The results showed that the application of sewage sludge promoted soil fertility by reducing soil pH and increasing content of OC, nitrogen and phosphorus in salt-affected mudflat soil, while soil electric conductivity (EC) increased with increasing sewage sludge (SS) application rates under waterlogged conditions. In this study, the rice growth was not inhibited by the highest EC of 4.43 dS m−1 even at high doses of SS application. The SS application increased yield of rice, promoted root growth, enhanced root activity and root flux activity, and increased the soluble sugar and amino acid content in the bleeding sap of rice plants at the tillering, jointing, and maturity stages. In conclusion, fertility enhancement through organic carbon amendment can “offset” the adverse effects of increased salinity and promote plant growth in salt-affected mudflat soil under waterlogged conditions.

Invasion, development, growth and egg laying by Meloidogyne javanica in Brassicaceae crops

Nematology ◽  
2001 ◽  
Vol 3 (5) ◽  
pp. 463-472 ◽  
Author(s):  
John Kirkegaard ◽  
Rod McLeod ◽  
Christopher Steel
Keyword(s):  
Intermediate Host ◽  
Subterranean Clover ◽  
Meloidogyne Javanica ◽  
Mature Female ◽  
Egg Laying ◽  
Field Pea ◽  
Crop Species ◽  
Egg Masses ◽  
Brassicaceae Species ◽  
Host Status

AbstractInvasion, development and egg laying by Meloidogyne javanica in 11 Brassicaceae and four non-Brassicaceae crop species/subspecies was investigated. At 10 to15 and 15 to 20°C, fodder rape cv. Rangi was invaded less than the good hosts tomato cv. Grosse Lisse and field pea cv. Dun but more than the poor host oat cv. Cooba. With an inoculum of 50 second stage juveniles (J2), invasion of Rangi, and the intermediate host subterranean clover cv. Trikkala, were similarly invaded when inoculated with 50 and 100 J2, cv. Rangi was invaded less than tomato. The intermediate host subterranean clover cv. Trikkala and Rangi were similarly invaded when inoculated with 50 and 100 J2 but cv. Trikkala was less invaded with 200 J2. Oat cv. Cooba was always less invaded than the other hosts. Invasion of 3-week-old seedlings of cv. Rangi and 12 cultivars of seven other Brassicaceae crop species/subspecies were similar. Three weeks after inoculation, more M. javanica had developed to the mature female stage in tomato than in the eight Brassicaceae species/subspecies. Females growing in tomato and field pea were always larger than those in rape cv. Rangi. Females in Rangi were larger but those in oilseed radish cv. Adagio were smaller than in 11 other cultivars of seven Brassicaceae, except in plants grown in winter. Egg masses from four Brassicaceae species contained fewer eggs than egg masses from tomato at 6 weeks after inoculation, but at 7 and 8 weeks only those from fodder rape cv. Korina had consistently fewer than tomato. Results are discussed in relation to host status, glucosinolates and potential use of Brassicaceae for control of Meloidogyne.

scholarly journals Imaging local soil kinematics during the first days of maize root growth in sand

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Floriana Anselmucci ◽  
Edward Andò ◽  
Gioacchino Viggiani ◽  
Nicolas Lenoir ◽  
Chloé Arson ◽  
...  
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Shear Strain ◽  
Root System ◽  
Capillary Rise ◽  
Image Correlation ◽  
Root Tip ◽  
Soil System ◽  
Local Soil ◽  
Initial Soil

AbstractMaize seedlings are grown in Hostun sand with two different gradings and two different densities. The root-soil system is imaged daily for the first 8 days of plant growth with X-ray computed tomography. Segmentation, skeletonisation and digital image correlation techniques are used to analyse the evolution of the root system architecture, the displacement fields and the local strain fields due to plant growth in the soil. It is found that root thickness and root length density do not depend on the initial soil configuration. However, the depth of the root tip is strongly influenced by the initial soil density, and the number of laterals is impacted by grain size, which controls pore size, capillary rise and thus root access to water. Consequently, shorter root axes are observed in denser sand and fewer second order roots are observed in coarser sands. In all soil configurations tested, root growth induces shear strain in the soil around the root system, and locally, in the vicinity of the first order roots axis. Root-induced shear is accompanied by dilative volumetric strain close to the root body. Further away, the soil experiences dilation in denser sand and compaction in looser sand. These results suggest that the increase of porosity close to the roots can be caused by a mix of shear strain and steric exclusion.

scholarly journals Does salinity affect lifestyle switching in the plant pathogen Fusarium solani?

2020 ◽  
Vol 2 (6) ◽  
Author(s):  
Louise Eydoux ◽  
Emily C. Farrer
Keyword(s):  
Root Growth ◽  
Fusarium Solani ◽  
Model Organism ◽  
Common Reed ◽  
Soil Salinization ◽  
Native Plant ◽  
Crop Species ◽  
Elevated Salinity ◽  
Weak Evidence ◽  
A Minor

Symbiotic microbes that live within plant hosts can exhibit a range in function from mutualistic to pathogenic, but the reason for this lifestyle switching remains largely unknown. Here we tested whether environmental stress, specifically salinity, is a factor that can trigger lifestyle switching in a fungus mainly known as a pathogen, Fusarium solani. F. solani was isolated from roots of Phragmites australis (common reed) in saline coastal marshes of Louisiana, USA, and we used Oryza sativa (rice) as a model organism from wetland environments to test the symbiont lifestyle. We plated rice seeds on control plates or plates with F. solani at three levels of salinity (0, 8 and 16 p.p.t.), then assessed germination and seedling growth after 20 days. Salinity strongly reduced percentage germination, slowed the timing of germination and reduced growth of rice. F. solani slowed germination, and it also caused a minor increase in root growth at medium salinity and a minor decrease in root growth at high salinity. Overall, despite being a common pathogen in other crop species (peas, beans, potatoes and many types of cucurbits), we found little evidence that F. solani has a strong pathogenic lifestyle in rice and we found weak evidence that pathogenicity may increase slightly with elevated salinity. These results have implications for both crops and native plant health in the future as soil salinization increases worldwide.

A Technique to Assay Herbicide Translocation and Effect on Root Growth

Weed Science ◽  
1970 ◽  
Vol 18 (6) ◽  
pp. 715-716 ◽  
Author(s):  
W. A. Gentner
Keyword(s):  
Phaseolus Vulgaris ◽  
Plant Growth ◽  
Root Growth ◽  
Growth And Development ◽  
Plant Tissues ◽  
Rapid Evaluation ◽  
Plant Growth And Development ◽  
Red Kidney Bean ◽  
Soil Level ◽  
Nutrient Solutions

A split-stem technique was devised for the rapid evaluation of herbicide effect on root growth and herbicide translocation. Four rows of adventitious root initials were prominent on the stem of red kidney bean [Phaseolus vulgaris L.] seedlings. They were excised at the soil level above the vascular plate. Excised stems were longitudinally split for a distance of 75 to 90 mm leaving two rows of root initials on each stem portion. Split-stem halves were immersed in herbicide-nutrient and nutrient solutions, respectively, contained in paired 25 by 150-mm test tubes. Subsequent plant growth and development of treated plants reflected effects of the herbicide on root growth. Herbicide translocation often was indicated by abnormalities of growth of plant tissues remote from the herbicide solution.

Enhanced tomato plant growth in soil under reduced P supply through microbial inoculants and microbiome shifts

2019 ◽  
Vol 95 (9) ◽  
Author(s):  
Namis Eltlbany ◽  
Mohamed Baklawa ◽  
Guo-Chun Ding ◽  
Dinah Nassal ◽  
Nino Weber ◽  
...  
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Growth Promotion ◽  
Bacterial Community Composition ◽  
Soil Microbial Communities ◽  
Rrna Gene ◽  
Pseudomonas Sp ◽  
Tomato Plants ◽  
Soil P ◽  
Bacterial Inoculants

ABSTRACT Soil microbial communities interact with roots, affecting plant growth and nutrient acquisition. In the present study, we aimed to decipher the effects of the inoculants Trichoderma harzianum T-22, Pseudomonas sp. DSMZ 13134, Bacillus amyloliquefaciens FZB42 or Pseudomonas sp. RU47 on the rhizosphere microbial community and their beneficial effects on tomato plants grown in moderately low phosphorous soil under greenhouse conditions. We analyzed the plant mass, inoculant colony forming units and rhizosphere communities on 15, 22, 29 and 43 days after sowing. Selective plating showed that the bacterial inoculants had a good rhizocompetence and accelerated shoot and root growth and nutrient accumulation. 16S rRNA gene fingerprints indicated changes in the rhizosphere bacterial community composition. Amplicon sequencing revealed that rhizosphere bacterial communities from plants treated with bacterial inoculants were more similar to each other and distinct from those of the control and the Trichoderma inoculated plants at harvest time, and numerous dynamic taxa were identified. In conclusion, likely both, inoculants and the rhizosphere microbiome shifts, stimulated early plant growth mainly by improved spatial acquisition of available nutrients via root growth promotion. At harvest, all tomato plants were P-deficient, suggesting a limited contribution of inoculants and the microbiome shifts to the solubilization of sparingly soluble soil P.

scholarly journals Root Microbiome Modulates Plant Growth Promotion Induced by Low Doses of Glyphosate

mSphere ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Dario X. Ramirez-Villacis ◽  
Omri M. Finkel ◽  
Isai Salas-González ◽  
Connor R. Fitzpatrick ◽  
Jeffery L. Dangl ◽  
...  
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Growth Inhibition ◽  
Growth Promotion ◽  
Action Spectrum ◽  
Dry Weight ◽  
Agricultural Fields ◽  
Low Doses ◽  
Shoot Dry Weight ◽  
Root Microbiome

ABSTRACT Glyphosate is a commonly used herbicide with a broad action spectrum. However, at sublethal doses, glyphosate can induce plant growth, a phenomenon known as hormesis. Most glyphosate hormesis studies have been performed under microbe-free or reduced-microbial-diversity conditions; only a few were performed in open systems or agricultural fields, which include a higher diversity of soil microorganisms. Here, we investigated how microbes affect the hormesis induced by low doses of glyphosate. To this end, we used Arabidopsis thaliana and a well-characterized synthetic bacterial community of 185 strains (SynCom) that mimics the root-associated microbiome of Arabidopsis. We found that a dose of 3.6 × 10−6 g acid equivalent/liter (low dose of glyphosate, or LDG) produced an ∼14% increase in the shoot dry weight (i.e., hormesis) of uninoculated plants. Unexpectedly, in plants inoculated with the SynCom, LDG reduced shoot dry weight by ∼17%. We found that LDG enriched two Firmicutes and two Burkholderia strains in the roots. These specific strains are known to act as root growth inhibitors (RGI) in monoassociation assays. We tested the link between RGI and shoot dry weight reduction in LDG by assembling a new synthetic community lacking RGI strains. Dropping RGI strains out of the community restored growth induction by LDG. Finally, we showed that individual RGI strains from a few specific phyla were sufficient to switch the response to LDG from growth promotion to growth inhibition. Our results indicate that glyphosate hormesis was completely dependent on the root microbiome composition, specifically on the presence of root growth inhibitor strains. IMPORTANCE Since the introduction of glyphosate-resistant crops, glyphosate has become the most common and widely used herbicide around the world. Due to its intensive use and ability to bind to soil particles, it can be found at low concentrations in the environment. The effect of these remnants of glyphosate in plants has not been broadly studied; however, glyphosate 1,000 to 100,000 times less concentrated than the recommended field dose promoted growth in several species in laboratory and greenhouse experiments. However, this effect is rarely observed in agricultural fields, where complex communities of microbes have a central role in the way plants respond to external cues. Our study reveals how root-associated bacteria modulate the responses of Arabidopsis to low doses of glyphosate, shifting between growth promotion and growth inhibition.

Studies of seed pelleting as an aid to legume inoculation. 5. Effects of incorporation of molybdenum compounds in the seed pellet on inoculant survival, seedling nodulation and plant growth of lucerne and subterranean clover

1980 ◽  
Vol 20 (102) ◽  
pp. 63 ◽  
Author(s):  
RR Gault ◽  
J Brockwell
Keyword(s):  
Nitrogen Fixation ◽  
Plant Growth ◽  
Nitrogen Content ◽  
Significant Relationship ◽  
Storage Time ◽  
Sodium Molybdate ◽  
Subterranean Clover ◽  
Ammonium Molybdate ◽  
Molybdic Acid ◽  
Molybdenum Disulphide

Four molybdenum compounds were mixed with lime and applied as coatings to inoculated seed of lucerne (Hunter River) and subterranean clover (Mount Barker). The seed was sown immediately in molybdenum-deficient soil in the field or stored for periods up to 84 days before sowing. As storage time lengthened, the survival of both lucerne and clover rhizobia was adversely affected by sodium molybdate but not by molybdic acid, ammonium molybdate or molybdenum disulphide. This effect was reflected in poorer nodulation in the sodium molybdate treatments. Nitrogen fixation, using foliage nitrogen content as an index, was always higher in the molybdenum treatments than in the no-molybdenum controls. Both species appeared able to extract molybdenum from molybdenum disulphide. Otherwise, there were no treatment differences in plant growth, but there was a significant relationship between the proportion of seedlings nodulated by the inoculant strains and the amount of nitrogen fixation. It is concluded that seed-applied molybdenum would benefit pasture establishment in some circumstances and would not interfere with inoculant survival or seedling nodulation provided that sodium molybdate was not used for the purpose.

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