scholarly journals Optimum Population Size of Indigenous P-solubilizing Bacteria to Correct P Availability in Acid Soils

2011 ◽  
Vol 16 (1) ◽  
pp. 55-62
Author(s):  
. Sabaruddin ◽  
. Marsi ◽  
. Desti
Keyword(s):  
Population Size ◽  
Acid Soils ◽  
P Availability ◽  
Optimum Population

scholarly journals Optimum Population Size of Indigenous P-solubilizing Bacteria to Correct P Availability in Acid Soils

2013 ◽  
Vol 16 (1) ◽  
pp. 55-62
Author(s):  
. Sabaruddin ◽  
. Marsi ◽  
. Desti
Keyword(s):  
Population Size ◽  
Fresh Water ◽  
Acid Soils ◽  
Available P ◽  
P Availability ◽  
Optimum Population ◽  
Tidal Swamp ◽  
P Content ◽  
Initial Content

Indonesian acid soils were used to determine an optimum population size of indigenous P-solubilizing bacteria (PSB) for solubilizating fixed P. The experiment consisted of two sub-experiments. Sub-experiment I was to isolate the indigenous PSB from Ultisols, Fresh-water lowland Inceptisols, and tidal-swamp Inceptisols. Subexpriment II was to study the capacity of the isolated PSB to correct P availability in acid soils by inoculating the isolated PSB into the tested soils at 0, 105, 1010, and 1015 cells. The population of the indigenous PSB in the tested soils increased as a result of the inoculation. Both Al-P and Fe-P content in the three tested soils decreased as compared with the initial content. The increases of available P were significantly correlated with the decreases both in Al-P (r2 = 0.68 for the Ultisols; r2 = 0.51 for the fresh-water Inceptisols; and r2 = 0.35 for the tidal-swamp Inceptisols) and in Fe-P (r2 = 0.91 for the Ultisols; r2 = 0.45 for the fresh-water lowland Inceptisols; and r2 = 0.78 for the tidal-swamp Inceptisols). The increases of available P were significantly correlated with the increases of thepopulation of the PSB (r2 = 0.60 for the Ultisols; r2 = 0.55 for the fresh-water lowland Inceptisols; and r2 = 0.69 for the tidal-swamp Inceptisols). The available P in the three tested soils sharply increased if the population size of the PSB was about 1 × 109 cfu g-1 of soil.Keywords: Al-P, Fe-P, fresh-water lowland, isolated, Pikovskaya medium, tidal swamp

scholarly journals Effects of Liming on Dithionate and Oxalate Extractable Aluminium in Acid Soils

2020 ◽  
pp. 1-9
Author(s):  
Esther Mwende Muindi
Keyword(s):  
Crop Production ◽  
Block Design ◽  
Chemical Properties ◽  
Acid Soils ◽  
P Availability ◽  
Acidic Soils ◽  
Training Centre ◽  
Wide Range ◽  
World Information ◽  
Considerable Work

Liming and phosphorus (P) applications are recommended practices for improving crop production in acid soils of the tropics. Although considerable work has been done to establish liming rates for acid soils in many parts of the world, information on the effects of lime on the forms of aluminium which actively sorb P in such soils is minimal. A greenhouse pot experiment was conducted at Waruhiu Farmers Training Centre, Githunguri to evaluate the effect of liming on oxalate and dithionate extractable aluminium in acid soils. Extremely (pH 4.48) and strongly (pH 4.59) acidic soils were evaluated. Four liming (CaO) rates namely 0, 2.2, 5.2 and 7.4 tonnes ha-1 for extremely acidic and 0, 1.4, 3.2, and 4.5 tonnes ha-1 for  strongly acidic soils were evaluated. The experiment was laid out in a Randomized Complete Block Design (RCBD) and replicated three times. Data collected included: initial soil chemical properties, oxalate (Alo) and dithionate (Ald) aluminium levels. The tested soils had high exchangeable Al (> 2 cmol Al kg-1), Al saturation of (> 20% Al) and low extractable P values (< 15 mg P kg-1 soil). Liming significantly (p=.05) reduced Alo by 70% and 68% in extremely and strongly acidic soils respectively and Ald by 78% in both extremely and strongly acidic soils compared to control. Use of 7.4 tonnes ha-1 of lime in extremely acidic soils and 4.5 tonnes ha-1 of lime in strongly acidic soils significantly (p=.05) reduced both Alo and Ald by > 68% compared to no lime. It was, therefore, concluded that liming contributes to the reduction of soluble Alo and Ald in acid soils of the Kenya highlands leading to increased soluble P availability. Studies are required to provide short and long term optimal liming rates that reduce Alo and Ald without distabilizing availability of other nutrients in field conditions under wide range of acid soils.

Sustainable welfare and optimum population size

2015 ◽  
Vol 18 (6) ◽  
pp. 1679-1699 ◽  
Author(s):  
Theodore P. Lianos ◽  
Anastasia Pseiridis
Keyword(s):  
Population Size ◽  
Optimum Population

Spot ν. furrow placement of phosphorus in potato at shillong

1988 ◽  
Vol 111 (1) ◽  
pp. 191-192
Author(s):  
T. S. Sahota ◽  
M. S. Virk ◽  
P. M. Govindakrishnan
Keyword(s):  
Relative Efficiency ◽  
Acid Soils ◽  
Water Soluble ◽  
P Availability ◽  
Spring Season ◽  
Water Soluble P ◽  
P Fixation ◽  
P Application ◽  
Fixation Capacity ◽  
P Fertilizers

Water soluble P fertilizers have been reported to be best for potato (Mattingly, 1963; Sharma, Grewal & Sud, 1976). However, they are irretrievably fixed in the acid soils because of their high P fixation capacity. Placement of P fertilizers is, therefore, necessary for their efficient use. Furrow placement of P fertilizers reduces their contact with soil and enhances P availability to the plants. Placement of P in spots, rather than in furrows, will further reduce the contact between the soil and the fertilizers and may improve its efficiency over furrow placement. The present investigation was undertaken to study the relative efficiency of these two methods of P application for potato in the spring season.

Phosphorus transformations in acid light-textured soils treated with dry swine manure

2005 ◽  
Vol 85 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Lotfi Khiari ◽  
Léon E. Parent
Keyword(s):  
Organic Matter ◽  
Swine Manure ◽  
Organic Ligand ◽  
Acid Soils ◽  
P Availability ◽  
P Fractionation ◽  
Soil C ◽  
Soil P ◽  
Metal Organic ◽  
P Fraction

Organic matter can sorb P in acid soils through metal-organic matter-phosphate complexes. The pyrophosphate extractable Al and Fe and soil C contents were hypothetized to influence P partitioning in Ferro-Humic Podzols. Reaction of added P may be mitigated by adding lime or organic matter as dry swine manure (DSM) together with mineral P fertilizers. Three soils had 40 to 50 g kg-1 of soil organic matter (SOM) content, and 76 to 140 mmol (Al + Fe)pyro kg-1. A peaty soil phase had 200 g SOM kg-1, and 58 mmol (Al + Fe)pyro kg-1. Rates of monoammonium phosphate were 0, 27, 69, and 144 kg P ha-1 in a simulated fertilizer band. Rates of DSM and lime were 800 and 185–369 mg per 35 mL of soil, respectively. After 6 wk of incubation, soil P was fractionated sequentially into aluminium bound P (Al-P), iron bound P (Fe-P), and loosely bound P. Total P, desorbed P and organic P were determined in separate subsamples. A proportion of 79–92% of added P was recovered as Al-P and Fe-P in the three low SOM soils, compared to 51–61% in the high SOM soil. The DSM increased loosely bound P from 25 to 34% in the high SOM soil and from 4.8 to 5.9% in low SOM soils. With DSM, the proportion of desorbed P was much higher in the high (70%) than in low SOM (22%) soils. Compared to the non-amended treatment, lime showed no significant effect on any P fraction but desorbed P. The DSM increased P availability in the fertilizer band considerably more in the soil having the lowest (Al + Fe)pyro/C ratio. Key words: P fractionation, organic ligand, P sorption, fertilizer band

scholarly journals Genetic analysis of aluminum tolerance in Brazilian barleys

2002 ◽  
Vol 37 (8) ◽  
pp. 1099-1103 ◽  
Author(s):  
Euclydes Minella ◽  
Mark Earl Sorrells
Keyword(s):  
Genetic Analysis ◽  
Population Size ◽  
Nutrient Solution ◽  
Single Gene ◽  
Aluminum Tolerance ◽  
Acid Soils ◽  
Al Toxicity ◽  
Root Tip ◽  
Al Tolerance ◽  
Hematoxylin Staining

Aluminum (Al) toxicity is a major factor limiting barley growth in acid soils, and genotypes with adequate level of tolerance are needed for improving barley adaptation in Brazil. To study the inheritance of Al tolerance in Brazilian barleys, cultivars Antarctica 1, BR 1 and FM 404 were crossed to sensitive Kearney and PFC 8026, and intercrossed. Parental, F1, F2 and F6 generations were grown in nutrient solution containing 0.03, 0.05 and 0.07 mM of Al and classified for tolerance by the root tip hematoxylin staining assay. Tolerant by sensitive F2 progenies segregated three tolerant to one sensitive, fitting the 3:1 ratio expected for a single gene. The F6 populations segregated one tolerant to one sensitive also fitting a monogenic ratio. The F2 seedlings from crosses among tolerant genotypes scored the same as the parents. Since the population size used would allow detection of recombination as low as 7%, the complete absence of Al sensitive recombinants suggests that tolerance in these cultivars is most probably, controlled by the same gene. Thus, the potential for improving Al tolerance through recombination of these genotypes is very low and different gene sources should be evaluated.

scholarly journals Isolasi Bakteri Pelarut Fosfat Genus Pseudomonas dari Tanah Masam Bekas Areal Perkebunan Karet di Kawasan Institut Teknologi Sumatera

2020 ◽  
Vol 21 (1) ◽  
pp. 40-48
Author(s):  
Muhammad Asril ◽  
Yuni Lisafitri
Keyword(s):  
Soil Microbes ◽  
Acid Soil ◽  
Acid Soils ◽  
Soil Samples ◽  
Pathogenicity Test ◽  
P Availability ◽  
Phosphate Solubilizing Bacteria ◽  
Potato Tubers ◽  
Phosphate Availability ◽  
Phosphate Solubilizing

ABSTRACTPhosphorus (P) is a nutrient that is needed by plants. The availability of this element is greatly influenced by soil pH. As for ultisol soils classified as acid soils, most of the P in the soil is not available and is bound to Fe and Al. Pseudomonas, a phosphate solubilizing bacteria are soil microbes that can improve the availability of P in acid soils. This study aims to obtain Pseudomonas indigenous, a phosphate solubilizing bacteria from the acid soil formerly used by rubber plantations in the Institut Teknologi Sumatera. The study was conducted from April to June 2018 which included soil chemical analysis, isolation of the genus Pseudomonads on specific media, testing of phosphate solubility on solid Pikovskaya medium and simple pathogenicity test on potato tubers. The results showed that the sample soil was acidic with a pH of 4.09 with a P-availability of 0.78 ppm. From the soil samples, four potential isolates were obtained from the genus Pseudomonas, namely GSP 01, GSP 13, GSP 15 and GSP 06, with phosphate solubility indexes of 0.885, 0.639, 0.619 and 0.568, respectively. Isolates have the best phosphate solubilizing index on days 4 through 7. The four potential isolates are not pathogenic, so they can be used as isolates to improve the availability of soil nutrients, especially phosphorus needed by plants.Keywords: acid soil, phosphate solubilizing bacteria, phosphate availability, PseudomonasABSTRAKFosfor (P) merupakan unsur hara yang sangat dibutuhkan oleh tanaman. Ketersediaan unsur ini sangat dipengaruhi oleh pH tanah. Pada jenis tanah ultisol yang digolongkan sebagai tanah masam, sebagian besar dari P di tanah dalam bentuk yang tidak tersedia untuk diserap oleh tanaman dan berikatan dengan Fe dan Al. Pseudomonas pelarut fosfat merupakan mikroba tanah yang dapat memperbaiki ketersediaan P pada tanah masam. Penelitian ini bertujuan untuk mendapatkan Pseudomonas pelarut fosfat indigenous dari tanah masam bekas lahan perkebunan karet di kawasan Institut Teknologi Sumatera. Penelitian dilaksanakan pada bulan April sampai Juni 2018 yang meliputi analisis kimia tanah, isolasi bakteri genus Pseudomonads pada medium spesifik, uji kemampuan pelarutan fosfat pada medium Pikovskaya padat serta uji patogenitas sederhana pada umbi kentang. Hasil penelitian menunjukkan bahwa tanah sampel bersifat masam dengan pH 4,09 dengan P tersedia sebesar 0,78 ppm. Dari sampel tanah diperoleh empat isolat potensial yang diperoleh merupakan genus Pseudomonas yaitu GSP 01, GSP 13, GSP 15 dan GSP 06, dengan indeks pelarutan fosfat berturut-turut sebesar 0,885, 0,639, 0,619 dan 0,568. Isolat memiliki indeks pelarutan fosfat terbaik pada hari ke-4 hingga hari ke-7. Keempat isolat potensial tidak bersifat patogen sehingga mampu dijadikan sebagai isolat yang dapat digunakan untuk memperbaiki ketersediaan unsur hara tanah terutama fosfor yang dibutuhkan oleh tanaman.Kata kunci: bakteri pelarut fosfat, fosfat tersedia, Pseudomonas, tanah masam 

scholarly journals Urban Optimum Population Size and Development Pattern Based on Ecological Footprint Model: Case of Zhoushan, China

2016 ◽  
Vol 3 (3) ◽  
Author(s):  
Yuan LU
Keyword(s):  
Population Size ◽  
Urban Environment ◽  
Ecological Footprint ◽  
Natural Capital ◽  
Development Pattern ◽  
Optimum Population ◽  
Footprint Model ◽  
Ecological Resources ◽  
Optimal Population ◽  
The City

The agglomeration of population in the city can reflect the prosperity in the economy, society and culture. However, it has also brought a series of problems like environmental pollution, traffic congestion, housing shortage and jobs crisis. The results can be shown as the failure of urban comprehensive function, the decline of city benefits, and the contradiction between socioeconomic circumstance and ecosystem. Therefore, a reasonable population capacity, which is influenced by ecological resources, urban environment, geographical elements, social and economic factors, etc., is objectively needed. How to deal with the relationship between the utilization of natural capital and development of the city is extremely essential. This paper takes Zhoushan Island as an example, which is the fourth largest island off the coast of China. Firstly, the interactively influencing factors of urban optimal population are illustrated. And method is chosen to study the optimal population size. Secondly, based on the model of ecological footprint (EP), the paper calculates and analyzes the ecological footprint and ecological capacity of the Zhoushan Island, in order to explore the optimal population size of the city. Thirdly, analysis and evaluation of the resources and urban environment carrying capacity is made. Finally, the solution of the existing population problems and the suggestion for the future development pattern of the city are proposed in the urban eco-planning of Zhoushan Island. The main strategies can be summarized in two aspects: one is to reduce the ecological footprint, the other is to increase the ecological supply. The conclusion is that the current population of Zhoushan Island is far beyond the optimum population size calculated by the ecological footprint model. Therefore, sustainable development should be the guidance for urban planning in Zhoushan Island, and a low-carbon development pattern for the city is advocated.

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