PHOSPHATE-DISSOLVING MICROORGANISMS ON SEED AND IN THE ROOT ZONE OF PLANTS

1962 ◽  
Vol 40 (9) ◽  
pp. 1181-1186 ◽  
Author(s):  
H. Katznelson ◽  
E. A. Peterson ◽  
J. W. Rouatt
Keyword(s):  
Strong Evidence ◽  
Root Zone ◽  
Red Clover ◽  
Crop Plants ◽  
Plant Roots ◽  
Selective Effect ◽  
Cereal Seed ◽  
Percentage Incidence

A high proportion (40–70%) of the bacteria on most of the seed tested solubilized phosphate precipitated in agar; flax and red clover were two striking exceptions with 11% and 24% respectively. The percentage incidence of these bacteria was considerably lower on the roots and in the rhizosphere of four out of the five crop plants studied than on their seed, being in the order of 10%. There was no strong evidence of a selective effect of plant roots on these organisms although barley appeared to favor them and oats to repress them somewhat.Phosphate-dissolving fungi were readily isolated from seed and plant roots. Cereal seed carried surprisingly few such fungi whereas grasses and clover had greater numbers. The phosphate-dissolving fungi isolated most frequently were species of Penicillium, Aspergillus, and Rhizopus; in addition, Candida, Oidiodendron, and Pseudogymnoascus species were isolated from roots and root-free soil.

Soil inorganic nitrogen content in commercial potato fields in New Brunswick

2003 ◽  
Vol 83 (4) ◽  
pp. 425-429 ◽  
Author(s):  
B. J. Zebarth ◽  
Y. Leclerc ◽  
G. Moreau ◽  
R. Gareau ◽  
P. H. Milburn
Keyword(s):  
Root Zone ◽  
Inorganic Nitrogen ◽  
Solanum Tuberosum L ◽  
Red Clover ◽  
Application Rate ◽  
Inorganic N ◽  
N Content ◽  
Growing Seasons ◽  
Commercial Potato ◽  
Soil Inorganic

Information on inorganic N content in commercial potato fields in Atlantic Canada is limited. Soil inorganic N measurements were collected from 228 commercial potato fields from 1999 to 2001. Soil NO3 content to 30 cm depth at planting ranged from 2 to 124 kg N ha-1, and was generally higher for preceding potato, red clover, or hay crops compared to preceding cereal or other crops. Soil NH4 content to 30 cm depth measured at planting ranged from 3 to 64 kg N ha-1, indicating that both soil NO3 and NH4 need to be measured to assess plant-available soil N content in spring. Soil NO3 content to 30-cm depth at tuber harvest ranged from 3 to 250 kg N ha-1, generally increased with increasing fertilizer N application rate, and differed among different potato cultivars. Soil NO3 content measured to 30-cm depth in spring ranged from 3 to 100% of soil NO3 at harvest in the preceding fall, indicating that highly variable losses of soil NO3 from the root zone occur between growing seasons. Key words: Nitrate, ammonium, Solanum tuberosum L.

STUDIES ON THE RELATIONSHIPS BETWEEN NEMATODES AND OTHER SOIL MICROORGANISMS: IV. INCIDENCE OF NEMATODE-TRAPPING FUNGI IN THE VICINITY OF PLANT ROOTS

1965 ◽  
Vol 11 (3) ◽  
pp. 491-495 ◽  
Author(s):  
E. A. Peterson ◽  
H. Katznelson
Keyword(s):  
Soil Microorganisms ◽  
Rhizosphere Soil ◽  
Red Clover ◽  
Root Surface ◽  
Plant Roots ◽  
Favorable Effect ◽  
Bacterial Isolates ◽  
Rhizosphere Effect ◽  
Root Extracts ◽  
Wheat Rhizosphere

A study was made of the occurrence of nematode-trapping fungi in the rhizosphere and on the root surface of different plants. Arthrobotrys oligospora was the predominant predaceous fungus isolated. It was almost completely absent from plant roots but occurred in varying frequency in rhizosphere soil and in root-free soil. The incidence of this fungus was consistently greater in the soybean rhizosphere and lower in the wheat rhizosphere than in corresponding soil devoid of roots, whereas for other plants, red clover, flax, etc., there was no obvious rhizosphere effect. Spore germination tests and growth of A. oligospora in root extracts of soybeans and wheat failed to account for the differences observed. However, bacterial isolates from the wheat rhizosphere were, on the whole, more antagonistic to this fungus than those from the soybean rhizosphere, whereas isolates from the latter appeared to exert a favorable effect.

scholarly journals Root-associated microbiomes of wheat under the combined effect of plant development and nitrogen fertilization

Microbiome ◽  
2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Shuaimin Chen ◽  
Tatoba R. Waghmode ◽  
Ruibo Sun ◽  
Eiko E. Kuramae ◽  
Chunsheng Hu ◽  
...  
Keyword(s):  
Community Structure ◽  
Plant Growth ◽  
Microbial Communities ◽  
Root Zone ◽  
N Fertilization ◽  
Plant Roots ◽  
Growth Stages ◽  
Ripening Stages ◽  
N Input

Abstract Background Plant roots assemble microbial communities both inside the roots and in the rhizosphere, and these root-associated microbiomes play pivotal roles in plant nutrition and productivity. Although it is known that increased synthetic fertilizer input in Chinese farmlands over the past 50 years has resulted in not only increased yields but also environmental problems, we lack a comprehensive understanding of how crops under elevated nutrient input shape root-associated microbial communities, especially through adjusting the quantities and compositions of root metabolites and exudates. Methods The compositions of bacterial and fungal communities from the roots and rhizosphere of wheat (Triticum aestivum L.) under four levels of long-term inorganic nitrogen (N) fertilization were characterized at the tillering, jointing and ripening stages. The root-released organic carbon (ROC), organic acids in the root exudates and soil organic carbon (SOC) and soil active carbon (SAC) in the rhizosphere were quantified. Results ROC levels varied dramatically across wheat growth stages and correlated more with the bacterial community than with the fungal community. Rhizosphere SOC and SAC levels were elevated by long-term N fertilization but varied only slightly across growth stages. Variation in the microbial community structure across plant growth stages showed a decreasing trend with N fertilization level in the rhizosphere. In addition, more bacterial and fungal genera were significantly correlated in the jointing and ripening stages than in the tillering stage in the root samples. A number of bacterial genera that shifted in response to N fertilization, including Arthrobacter, Bacillus and Devosia, correlated significantly with acetic acid, oxalic acid, succinic acid and tartaric acid levels. Conclusions Our results indicate that both plant growth status and N input drive changes in the microbial community structure in the root zone of wheat. Plant growth stage demostrated a stronger influence on bacterial than on fungal community composition. A number of bacterial genera that have been described as plant growth-promoting rhizobacteria (PGPR) responded positively to N fertilization, and their abundance correlated significantly with the organic acid level, suggesting that the secretion of organic acids may be a strategy developed by plants to recruit beneficial microbes in the root zone to cope with high N input. These results provide novel insight into the associations among increased N input, altered carbon availability, and shifts in microbial communities in the plant roots and rhizosphere of intensive agricultural ecosystems.

OBSERVATIONS ON FUNGI ASSOCIATED WITH PLANT ROOTS

1958 ◽  
Vol 4 (3) ◽  
pp. 257-265 ◽  
Author(s):  
E. A. Peterson
Keyword(s):  
Soil Type ◽  
Rhizosphere Soil ◽  
Red Clover ◽  
Root Surface ◽  
Plant Age ◽  
Seedling Stage ◽  
Plant Roots ◽  
Dilution Technique ◽  
Fungal Flora ◽  
Stages Of Growth

Plant age and soil type influence the nature of the fungal flora associated with plant roots. Total numbers of fungi in the rhizosphere of wheat, as determined by the dilution technique, increased with plant age but the degree of fungal stimulation appeared to depend upon soil type. Penicillia and certain species of the Mucorales were relatively more abundant on the root surface and in the rhizosphere at the seedling stage than at later stages of growth. Species of Fusarium and/or Cylindrocarpon (depending upon soil type) and various sterile dark fungi were predominant on the roots of healthy red clover and wheat, but were relatively rare in rhizosphere and non-rhizosphere soil.

scholarly journals Produksi Benih Kentang Sistem Aeroponik dan Root Zone Cooling dengan Pembedaan Tekanan Pompa di Dataran Rendah

2017 ◽  
Vol 44 (3) ◽  
pp. 299
Author(s):  
Eni Sumarni ◽  
Arief Sudarmaji ◽  
Herry Suhardiyanto ◽  
Dan Satyanto Krido Saptomo
Keyword(s):  
Potato Tuber ◽  
Root Zone ◽  
Block Design ◽  
Plant Roots ◽  
Growth And Yield ◽  
Potato Tubers ◽  
Orthogonal Contrasts ◽  
Cooling Temperature ◽  
Randomized Block Design ◽  
Pump Pressure

<p>ABSTRACT<br /><br />Nutrition  pumps  pressure is important in aeroponic. Optimal  pump  pressure produces well oxygenation, so that increases the dissolved oxygen content in the nutrition. It is good for plant roots. The purpose of this study was to determine pump pressure on the growth and yield  potato seeds grown in aeroponics in lowland 125 m asl with root zone cooling. This study used a randomized block design non factorial. Data were analyzed using analysis of variance followed by a further test of orthogonal contrasts at the level of α = 5%. Results showed that different pump pressure on the provision of nutrient, temperature cooling in the root zone gave different results on the number of potato tubers per plant and weight per tuber in each variety. Root zone cooling temperature 15 °C, the pump pressure&gt; 1.5 atm produce highest number of tubers per plant, i.e. 11.8 tuber of Granola variety and 8.2 tuber of Atlantic variety.  The was no tuber produced from control (without referigeration). The highest weights per tuber (10.35 and 5.01 g for Atlantic and Granola variety, respectively) were reached with cooling temperature at 15 °C and the pump pressure &gt; 1.5 atm.<br /><br />Keywords: evaporative cooling, hydroponics, potato, tuber, variety     <br /><br /></p>

scholarly journals Efficient Technology for Introduction Catch-Crops Into Soil

2006 ◽  
Vol 1 ◽  
pp. 51
Author(s):  
А. Cesnieks ◽  
А. Vilde ◽  
S. Cesnieks ◽  
J. Liepiņš ◽  
М. Ausmane ◽  
...  
Keyword(s):  
Red Clover ◽  
Sharp Decrease ◽  
Crop Plants ◽  
Organic Fertilizers ◽  
Catch Crop ◽  
Efficient Technology ◽  
Catch Crops ◽  
Winter Rape ◽  
Turn Over

A sharp decrease in the number of cattle in Latvia has essentially affected the possibilities to introduce organic fertilizers into soil. A solution of this problem may be growing catch-crop plants. The purpose of this study is to clarify the factors, technologies and machinery ensuring good and widespread introduction of catch-crops (winter rape, spring rape, red clover, fallow) without their previous shredding. It is found that unthreaded catch- crop plants may be qualitatively introduced into soil using a combined aggregate by orienting them in the direction of the movement of the aggregate and inclining them towards the surface of the field (rolling with the roller) and simultaneously plugging in with a plough which has a disk knife in front of each body to cut the inclined plants and a greater width (50 cm), and adjustable mouldboard curvature having improved skimmers to avoid clogging and to turn over the arable strips in a better way and to ensure more complete plugging of plants into soil. The technology of introducing catch-crops into soil without previous disintegration has been tested in practice and it is an environment-saving means of preserving and raising soil fertility. It is economically efficient in comparison with the introduction of previously shredded plants presently used on farms. It is possible to raise the introduction quality of unthreaded plants (also long-stalked ones) to 96-98%. Optimization the technology and the plough completion allow save labor – 1.4-1.8 men h ha-1, fuel 6-8 kg ha-1 and financial means 5,60-7,20 Ls ha-1.

scholarly journals Accumulation and dynamics of manganese in raspberry

2019 ◽  
Vol 113 (2) ◽  
pp. 221
Author(s):  
Senad MURTIĆ ◽  
Emir ŠAHINOVIĆ ◽  
Hamdija ČIVIĆ ◽  
Emina SIJAHOVIĆ
Keyword(s):  
Atomic Absorption Spectroscopy ◽  
Manganese Oxides ◽  
Scientific Literature ◽  
Root Zone ◽  
Ph Value ◽  
Ore Deposits ◽  
Plant Roots ◽  
Food Crops ◽  
Manganese Ore ◽  
Good Ability

<p>The aim of this study was to evaluate the dynamics of Mn in ‘soil - raspberry’ system on the area around the manganese ore deposits Radostovo in Bužim municipality. Atomic absorption spectroscopy was used to determine the concentration of Mn in soil and plant samples. Fe, Zn and Cu concentration in soil and raspberry plants was also subject of analysis, since these elements have antagonistic relationship with Mn in soils. The concentration of available Mn in soils was low, although the total Mn in the same soils exceeded the Mn toxic values noted in the scientific literature. The chemical and physical properties of the examined soils characterized by a relatively high pH value and good ability to store root-zone air certainly contributed to the decreasing release of available Mn<sup>2+</sup> from manganese oxides in soils as well as Mn<sup>2+</sup> oxidation to insoluble Mn<sup>3+</sup> or Mn<sup>4+</sup> ions, resulting in low uptake of Mn by plant roots. The results of study also showed that the absorbed Mn mostly accumulates in leaves and roots of raspberry, and much less in the stem and fruits. That rule in Mn distribution within raspberry plant is in fact identical to all food crops.</p>

EFFECT OF PLANT ROOTS ON CHEMICAL AND BIOCHEMICAL PROPERTIES OF SURROUNDING DISCRETE SOIL ZONES

1988 ◽  
Vol 68 (2) ◽  
pp. 233-242 ◽  
Author(s):  
J. F. DORMAAR
Keyword(s):  
Root Zone ◽  
Chemical Properties ◽  
Outer Zone ◽  
Bouteloua Gracilis ◽  
Biochemical Properties ◽  
Plant Roots ◽  
Grass Species ◽  
Detailed Knowledge ◽  
Blue Grama ◽  
Wheat Field

The chemical and biochemical properties within and immediately adjacent to the root zone of two grass species were studied over a 5-wk period. The experiment utilized a simple container comprising five sandwiched compartments giving a center or "rhizosphere" zone, two intermediate zones, and two outer zones. Soil samples were taken from an Orthic Brown, Dark Brown, and Black Chernozemic Ah horizon and from the Orthic Dark Brown Chernozemic Ap horizons of the unfertilized part of a continuous wheat field and the fallow field of a wheat-fallow rotation, both under cultivation for 70 yr. The two grasses were blue grama (Bouteloua gracilis (H.B.K.) Lag.) and rye (Secale céréale L. 'Frontier'). High root densities were achieved by the end of the study, especially with the blue grama. Changes in pH over time were slight but consistent; they decreased in the Black Chernozemic soil and increased in the other soils. A redistribution of labile phosphorus was caused by the presence of the plant roots. The Orthic Dark Brown Ah and Ap horizon soils reacted differently to the conditions of the study. Monosaccharides always increased in the rhizosphere zone and generally decreased in the zone adjacent to the rhizosphere zone in the case of rye and in the outside zone in the case of blue grama. The ratio galactose + mannose/arabinose + xylose always increased towards the outer zone. Although the presence of roots influenced the measured chemical properties of the soil surrounding them, there were no overall common trends. The results, even in this simplified system, demonstrated complex and interrelated effects (P < 0.01) of soil type, plant species, and time on the biochemical dynamics in and near the rhizosphere. The properties of rhizosphere soil are system specific. To interpret the processes within the system, detailed knowledge of the soil organic matter, the physiology of the species root, and the effect on each other is obligatory. Key words: Rhizosphere, Chernozemic Ah/Ap horizons, blue grama, rye, monosaccharides

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