Progress in selected areas of rhizosphere research on P acquisition

Soil Research ◽  
2003 ◽  
Vol 41 (3) ◽  
pp. 471 ◽  
Author(s):  
S. N. Trolove ◽  
M. J. Hedley ◽  
G. J. D. Kirk ◽  
N. S. Bolan ◽  
P. Loganathan
Keyword(s):  
Agricultural Research ◽  
50Th Anniversary ◽  
Developed Countries ◽  
P Uptake ◽  
Low Grade ◽  
P Efficiency ◽  
Soil Science Society ◽  
Soil P ◽  
Mycorrhizal Associations ◽  
Maintenance Requirements

Large reserves of P have accumulated in soils of developed countries because additions of P fertiliser to sustain agricultural production have exceeded crop removal. By contrast, in many developing countries in the tropics and subtropics, soil P reserves are gravely low and large additions are required before maintenance requirements begin to decline. In addition, the cost of P fertiliser will increase as the currently accessible deposits of high-grade phosphate rock (PR) diminish. Developing plants that efficiently tap soil P reserves and low grade PR is therefore a priority for agricultural research. For the 50th anniversary of the New Zealand Soil Science Society, this paper reviews research on P efficiency in plants, conducted by staff, students, and research associates of Massey University, in the context of other research into plant mechanisms that enhance P uptake, including effects of root geometry, mycorrhizal associations, and root-induced changes in the soil. Techniques for fractionation of soil P are highlighted.

scholarly journals Phosphorus Uptake and Utilization Efficiency in Peanut1

1997 ◽  
Vol 24 (1) ◽  
pp. 1-6 ◽  
Author(s):  
K. R. Krishna
Keyword(s):  
Root Length ◽  
Phosphorus Uptake ◽  
P Uptake ◽  
Utilization Efficiency ◽  
P Efficiency ◽  
Efficiency Ratio ◽  
Soil P ◽  
Arachis Hypogaea L ◽  
P Accumulation ◽  
Total P

Abstract Cultivars of a crop can differ genetically with respect to their uptake, translocation, accumulation, and use of phosphorus. The objective of this paper was to evaluate genetic variation for P uptake and utilization among peanut (Arachis hypogaea L.) genotypes. Several traits contribute to the total P efficiency of the genotype, including root length, rate of P uptake per unit root length, leaf and pod characters such as P accumulation, and dry matter/yield produced per unit P absorbed [i.e., P efficiency ratio (PER)]. Peanut genotypes with increased P uptake and higher PER were identified. Some genotypes sustained higher PER at both low and high soil P availabilities.

Uptake of phosphorus from different sources by Lotus Pedunculatus and three genotypes of Trifolium Repens .1. Plant yield and phosphate efficiency

Soil Research ◽  
1996 ◽  
Vol 34 (6) ◽  
pp. 1015 ◽  
Author(s):  
SN Trolove ◽  
MJ Hedley ◽  
JR Caradus ◽  
AD Mackay
Keyword(s):  
White Clover ◽  
Trifolium Repens ◽  
Unit Length ◽  
P Uptake ◽  
Selection Line ◽  
P Efficiency ◽  
Soil P ◽  
Lotus Pedunculatus ◽  
Unit Plant ◽  
Different Sources

The breeding of phosphate (P) efficient pastoral legumes could reduce the amount of fertiliser required on pastoral farms. In this study, Lotus pedunculatus and 3 genotypes of white clover (Trifolium repens L.) known to differ in their ability to respond to added P were grown on unfertilised soil and soil to which either monocalcium phosphate (MCP) or North Carolina phosphate rock (NCPR) were added. White clover genotype 8D (a selection line from Crau) had a greater (P < 0.05) internal P efficiency (shoot DM production per unit plant P) than 1A (a selection line from Gwenda) or lotus on unfertilised soil, whereas on fertilised soil, lotus had a significantly higher (P < 0.05) internal P efficiency than 2 of the white clover genotypes on MCP-fertilised soil (P < 0.01) and all 3 white clover genotypes on NCPR-fertlised soil (P < 0.01). Lotus also had a higher (P < 0.01) external P efficiency (total P uptake) than all 3 white clover genotypes on the 2 fertilised treatments. This was due to a greater root length, not a greater P uptake per unit length.

Yield and P uptake by rice and wheat grown in a sequence as influenced by phosphate fertilization with diammonium phosphate and Mussoorie rock phosphate with or without crop residues and phosphate solubilizing bacteria

2003 ◽  
Vol 141 (3-4) ◽  
pp. 359-369 ◽  
Author(s):  
S. N. SHARMA ◽  
R. PRASAD
Keyword(s):  
Rock Phosphate ◽  
Field Experiments ◽  
Agricultural Research ◽  
Indian Agricultural Research Institute ◽  
Cropping System ◽  
P Uptake ◽  
Diammonium Phosphate ◽  
Low Grade ◽  
Phosphate Solubilizing Bacteria ◽  
Phosphate Solubilizing

The field experiments were carried out at the Indian Agricultural Research Institute, New Delhi during 1996–97 to 1998–99 to study the effect of phosphate solubilizing bacteria (PSB) and incorporation of wheat and rice residue on the relative efficiency of diammonium phosphate (DAP) and Mussoorie rock phosphate (MRP) in three cycles of rice–wheat cropping system. Application of MRP had no significant effect on grain and straw yield and P uptake by rice and wheat; however, when it was inoculated with PSB, it increased grain and straw yields as well as P uptake of both rice and wheat. Efficiency of MRP+PSB was further increased when rice and wheat residues were incorporated and this practice made MRP on a par with DAP. Available P in soil after three cycles of rice–wheat cropping was more after MRP+PSB and incorporation of rice and wheat residues than after DAP. The results of the present study, therefore, indicate that low grade rock phosphate such as MRP can be advantageously utilized in rice–wheat cropping system when applied with PSB inoculation and incorporation of rice and wheat residues.

Per Pinstrup-Anderson, Alan Berg and Martin"Forman (eds.). International Agricultural Research and Human Nutrition. Washington, D.C.: International Food Policy Research Institute, and Rome: UN Administrative Committee on Coordination/ Sub-Committee on Nutrition. 1984. xvii+326 pp.Paperback edition.

1987 ◽  
Vol 26 (2) ◽  
pp. 222-224
Author(s):  
Sohail Jehangir Malik
Keyword(s):  
Industrial Development ◽  
Food Policy ◽  
Agricultural Research ◽  
Policy Research ◽  
Developed Countries ◽  
Agricultural Technology ◽  
Political Factors ◽  
Income Elasticities ◽  
Increase Productivity ◽  
Land Saving

During the last few decades there has been a sharp transition in economic doctrine, within the context of economic growth, on the relative contributions of agriculture and industrial development. There has been a shift away from the earlier 'industrial fundamentalism' to an emphasis on the significance of growth in agricultural productivity and production. The focus, especially in the context of the present-day less developed countries like Pakistan, has sharpened with the rapid growth in demand for food, resulting from the increasing growth in population and the high income-elasticities of the demand for food. Coupled with this is the transition from resource-based agriculture to science-based agriculture. Agricultural economists are unanimous in the view that by the end of this century all increases in world food production will come from higher yields, i.e. increased output per hectare. This increasing emphasis on 'land-saving' technology to increase productivity and production has resuited from the growing population pressures on land and declining land-man ratios. Agricultural research has come to the fore in providing technologies that increase productivity and production. However, these technologies do not explicitly take into account the equity aspects of the problem. The extent to which the poor gain or lose from the introduction of a new agricultural technology depends on a host of complex and interrelated socio-economic and political factors such as the existing distribution of productive resources, access to modem inputs, the structure of the market, etc.

scholarly journals LINC-42. EPIDEMIOLOGICAL OVERVIEW OF CHILDHOOD CNS TUMORS IN THE NEUROSURGICAL UNIT IN YEREVAN, ARMENIA

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii386-iii386
Author(s):  
Nune Karapetyan ◽  
Samvel Danielyan ◽  
Gevorg Tamamyan ◽  
Armen Tananyan ◽  
Liana Safaryan ◽  
...  
Keyword(s):  
Medical Center ◽  
Survival Rates ◽  
Developed Countries ◽  
Cns Tumors ◽  
Malignant Neoplasms ◽  
Low Grade ◽  
Embryonal Tumors ◽  
Low Grade Gliomas ◽  
Neurosurgical Treatment

Abstract BACKGROUND Central nervous system (CNS) tumors are the second most common malignant neoplasms among children worldwide. The current paper aims to analyze the situation in pediatric neuro-oncology in Armenia from the neurosurgical perspective. METHODS We have collected data of pediatric patients with CNS tumors treated in the Neurosurgery department of “Surb Astvasamayr” Medical Center from 01.01.2010 till 01.12.2019. Incidence by gender, age at diagnosis, and histopathology results were calculated. Survival rates were calculated based on the follow-up results performed until 30.12.2019. RESULTS Hospital-based data showed that during the previous 10 years 47 patients with CNS tumors received neurosurgical treatment in the unit, among them 66% were females. 38.3%, 31.9% and 29.8% of diagnosed patients were aged 0–4, 5–9, and 10–18 respectively. In 41 cases, the disease was not disseminated at diagnosis. The most common observed malignancies were low-grade gliomas (21.3%) and embryonal tumors (19.1%), followed by high-grade gliomas (14.9%) and ependymal tumors (8.5%). Follow-up information only for 33 patients is available. From them, 14 are dead and 19 alive. Survival rates in most common groups were 62.5%, 80%, 50%, and 50% respectively. The median follow-up time was 18 months (range 1–113 months). CONCLUSION Similar to the data reported in the literature, low-grade gliomas, and embryonal tumors are the most frequent pediatric CNS tumors in Armenia. On the other hand, the pediatric CNS tumor survival rates are lower compared to those reported in developed countries.

scholarly journals Phosphorus effects of recycled products from municipal wastewater on crops in a field experiment

2017 ◽  
Vol 63 (No. 10) ◽  
pp. 475-482 ◽  
Author(s):  
Vogel Telse ◽  
Nelles Michael ◽  
Eichler-Löbermann Bettina
Keyword(s):  
Field Experiment ◽  
Municipal Wastewater ◽  
Spring Barley ◽  
P Uptake ◽  
Control Treatment ◽  
First Year ◽  
Soil P ◽  
Second Year ◽  
Fertilizing Effect ◽  
Sludge Ash

In this study, the phosphorus (P) fertilizing effects of struvite, one thermochemical-treated sewage sludge ash (SSA) based on Ca-P (Ca-SSA) and one full sulfuric acid-digested SSA based on Al-P (Al-SSA) were analysed in comparison to triple superphosphate (TSP) and a control treatment (CON) without P application in a two-year field experiment. In the field experiment, the effects of the recycling products on crop yield, P uptake and labile soil P fractions were analysed. In addition, the effect of nitrogen and magnesium contained in struvite was investigated in the second year of the experiment compared to TSP and CON. In the first year, spring barley was cultivated in the field experiment; and in the second year, it was forage rye followed by sorghum. In the second year, the relative P effectiveness (forage rye, sorghum) of the recycling products compared to TSP increased in the order: Ca-SSA (81%, 91%) ≤ Al-SSA (91%, 96%) = struvite (102%, 110%). In addition, an magnesium fertilizing effect of struvite could be demonstrated. The results show that the recycling products from wastewater treatment are appropriate to substitute rock phosphate-based fertilizers.

scholarly journals Spatiotemporal dynamics of soil phosphorus and crop uptake in global cropland during the 20th century

2017 ◽  
Vol 14 (8) ◽  
pp. 2055-2068 ◽  
Author(s):  
Jie Zhang ◽  
Arthur H. W. Beusen ◽  
Dirk F. Van Apeldoorn ◽  
José M. Mogollón ◽  
Chaoqing Yu ◽  
...  
Keyword(s):  
Crop Production ◽  
Soil Phosphorus ◽  
Fertilizer Application ◽  
P Uptake ◽  
Vital Role ◽  
Spatially Explicit ◽  
Explicit Model ◽  
Spatially Explicit Model ◽  
Soil P ◽  
Crop Uptake

Abstract. Phosphorus (P) plays a vital role in global crop production and food security. In this study, we investigate the changes in soil P pool inventories calibrated from historical countrywide crop P uptake, using a 0.5-by-0.5° spatially explicit model for the period 1900–2010. Globally, the total P pool per hectare increased rapidly between 1900 and 2010 in soils of Europe (+31 %), South America (+2 %), North America (+15 %), Asia (+17 %), and Oceania (+17 %), while it has been stable in Africa. Simulated crop P uptake is influenced by both soil properties (available P and the P retention potential) and crop characteristics (maximum uptake). Until 1950, P fertilizer application had a negligible influence on crop uptake, but recently it has become a driving factor for food production in industrialized countries and a number of transition countries like Brazil, Korea, and China. This comprehensive and spatially explicit model can be used to assess how long surplus P fertilization is needed or how long depletions of built-up surplus P can continue without affecting crop yield.

Influence of soil texture on fertilizer and soil phosphorus transformations in Gleysolic soils

2003 ◽  
Vol 83 (4) ◽  
pp. 395-403 ◽  
Author(s):  
Z. Zheng ◽  
L. E. Parent ◽  
J. A. MacLeod
Keyword(s):  
Soil Texture ◽  
Agricultural Soils ◽  
Sandy Loam ◽  
Clay Content ◽  
P Uptake ◽  
Hordeum Vulgare L ◽  
P Fractionation ◽  
Soil P ◽  
Plant P Uptake ◽  
Heavy Clay

The P dynamics in soils should be quantified in agricultural soils to improve fertilizer P (FP) efficiency while limiting the risk of P transfer from soils to water bodies. This study assessed P transformations following FP addition to Gleysolic soils. A pot experiment was conducted with five soils varying in texture from sandy loam to heavy clay, and receiving four FP rates under barley (Hordeum vulgare L.)-soybean (Glycine max L.) rotations. A modified Hedley procedure was used for soil P fractionation. Soil resin-P and NaHCO3-Pi contents were interactively affected by texture and FP. The NaHCO3-Po, NaOH-Po, HCl-P and H2SO4-P were only affected by soil texture. Proportions of 78 and 90% of the variation in labile and total P were, respectively, related to soil clay content. The FP addition increased resin-P, NaHCO3-Pi and NaOH-Pi and -Po contents in coarse-textured soils, but the amount added was not sufficient to mask the initial influence of soil texture on the sizes of soil P pools. Plant P uptake was proportional to FP rate but less closely linked to clay content. The average increase in labile P per unit of total FP added in excess of plant exports was 0.85, 0.8 2 , 0.73, 0.55 and 0.24 for the sandy loam, loam, clay loam, clay and heavy clay soil, respectively. The results of this study stress the important of considering soil texture in Gleysolic soils when assessing P accumulation and transformations in soils, due to commercial fertilizers applied in excess of crop removal. Key words: P fractions, clay content, fertilizer P, plant P uptake, soil texture

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