+ Site Statistics
References:
52,654,530
Abstracts:
29,560,856
PMIDs:
28,072,755
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn

+ Translate
+ Recently Requested

Determination of microbial phosphorus Kp factors in a spodosol: influence of extractant, water potential, and soil horizon



Determination of microbial phosphorus Kp factors in a spodosol: influence of extractant, water potential, and soil horizon



Soil Biology and Biochemistry 36(12): 1925-1934



The acidic, sandy soils in the southeastern US are phosphorus (P) limited for forest production and are commonly fertilized with P. There is no P retention capacity in the A horizon. However, microbial biomass may immobilize and retain P fertilizer before it is leached below seedling rooting depth making P fertilization more efficient. An accurate estimation of microbial P is dependent on measuring the K(p) factor in the fumigation-extraction method. The overall purpose of this study was to examine the fumigation-extraction method for microbial P in acidic, forested, sandy soils. The three objective were: to determine which extractant was the most useful extracting microbial P by comparing the standard basic extractant, 0.5 M NaHCO3 at pH 8.5, against several acidic and oxalate extractants; to evaluate whether soil water potential influenced the K(p) factor; and to test whether the K(p) factor differed by soil horizon within the profile of a representative Flatwoods Spodosol. Three millimolar oxalate was determined to be the preferred extractant due to its efficient removal of microbial P and ease of analysis. The K(p) factor was dependent on soil water potential and horizon. The range in K(p) at different water potentials using 3 mM oxalate was from 0.31 to 0.67 in the A horizon, 0.48 to 0.91 in the E horizon, and 0.22 to 0.45 in Bh horizon. The highest K(p) factors tended to be at water potentials near saturation and under the driest condition. Differences in K(p) were attributed to the influence that water potential and soil horizon had on microbial assemblages and diversity. Using a literature value of K(p), instead of measuring K(p) directly, caused an overestimate of - 7 to 63% in the A horizon, 63-160% in the E horizon and 7-32% in the Bh horizon. The best estimate of microbial P required that K(p) be evaluated for specific soil conditions.

(PDF emailed within 0-6 h: $19.90)

Accession: 004100605

Download citation: RISBibTeXText

DOI: 10.1016/j.soilbio.2004.05.012


Related references

The aim of determination of assimilable phosphorus in the soil. Introduction to the study of the influence of the pH of the extractant on the content of phosphorus extracted.. An. Primeira Reun. Brasil Ciene. Solo, 1950. 281-287, 1950

Phosphorus mineralization and microbial biomass in a Florida Spodosol: effects of water potential, temperature and fertilizer application. Biology and Fertility of Soils 28(3): 244-252, 1999

Phosphorus Retention by the Ap Horizon of a Spodosol as Influenced by Calcium Amendments. Soil Science 168(10): 9-706, 2003

Potential mobility of accumulated phosphorus in soil as estimated by the indices of q i plots and by extractant. Soil Science 152(3): 204-209, 1991

Phosphorus mineralization kinetics and response of microbial phosphorus to drying and rewetting in a Florida spodosol. Soil biology and biochemistry 30(10-11): 1323-1331, 1998

Water-soluble phosphorus as affected by soil to extractant ratios, extraction times, and electrolyte. Communications in soil science and plant analysis6(7-8): 925-935, 2005

Influence of phosphorus loading on microbial processes in the soil and water column of wetlands. Pages 249-273 1999, 1999

The influence of soil water potential on the locality of microbial activity in aggregates of an arid sandy loess soil. Mitteilungen der Deutschen Bodenkundlichen Gesellschaft 62: 9-42, 1990

Effect of lime and phosphorus applied to a florida usa ultisol a sandy entisol and a spodosol on corn growth phosphorus uptake and soil characteristics. Soil & Crop Science Society of Florida Proceedings 48: 157-165, 1989

Potential microbial risk factors related to soil amendments and irrigation water of potato crops. Journal of Applied Microbiology 103(6): 2542-2549, 2007

The influence of soil volume on the absorption of soil phosphorus by plants and on the determination of labile soil phosphorus. Plant & Soil, 18: 77-84, 1963

Microbial immobilization of phosphorus as a potential means of reducing phosphorus pollution of water. Bulletin of Environmental Contamination and Toxicology 34(4): 587-596, 1985

Phosporus mineralization kinetics and response of microbial phosphorus to drying and rewetting in a Florida spodosol. Soil Biology & Biochemistry 30(10-11): 1323-1331, Sept, 1998

Study on the suitable phosphorus extractant for phosphorus availability indices in Ayutthaya lowland soil series in Great Mae Klong basin. Proceedings of 41st Kasetsart University Annual Conference, 3-7 February, 2003 Subject: Plants and Agricultural Extension and Communication: 93-100, 2003