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Pottasum status and exchange characteristics of some lowland soils in Luzon / Pearl R. Basilio.

By:

Basilio, Pearl R [author]

Contributor(s):

San Valentin, Genaro O [adviser]

Material type: Text

TextLanguage: English Publication details: Los Baños, Laguna, 1988. Cavite State University- Main Campus,Description: 85 pages : illustrations ; 28 cmContent type:

text

Media type:

unmediated

Carrier type:

volume

Subject(s):

DDC classification:

631.4 B29 1988

Online resources:

Click here to view thesis abstract and table of contents

Abstract: BASILIO, PEARL R., University of the Philippines at Los Banos, October, 1988. Potassium Status and Exchange Characteristics of Some Lowland Soils in Luzon. Major Professor: Dr. Genaro 0. San Valentin The study was conducted to evaluate the potassium (K) status and exchange characteristics of ten soils representing important lowland areas in Luzon. An inventory of the K content of the soils was made using the following extracting solutions: hydrogen fluoride (HF) for total K, sodium tetraphenylboron (NaTPB) for nonexchangeable K and ammonium acetate (MNH,0Ac) for exchangeable K. Quantity/Intensity (Q/I) parameters derived from the Q/I curves were tested against K availability indices to assess its value in characterizing K status. Q/I data described K status by reJating the intensity (1) of K to the amount (Q) of labile K in the soil. A greenhouse experiment was conducted to determine the influence of K addition and K uptake on the Q/I parameters of selected lowland soils and at the same time assess their K supplying capacity. A high soil to plant ratio was used to exhaust available K supply in a_ short period. Right of the soils studied contained 2:1 expanding type of clay minerals Bantog and Tarlac were dominated by vermiculite. X-ray diffraction patterns of the sand fractions of all the soils showed the presence of quartz and feldspars. The soils varied in their chemical characteristics which include pH, cation exchange capacity, organic matter content, changeable K, NaTPB-extractable K, ark., Z\K9 and pEck, The exchangeable K contents (NH4OAc extractable K) of eight soils were found to be below the satisfactory level of exchangeable K for rice. Only San Manuel T and Rantog had an exchangeable K level higher than 0.2 me/100g. Significant correlations were found between exchangeable K and aRK, (x = 0.77) and /\K° (r = -0.96). Sodium tetraphenylboron extractions gave higher values for K than NH4QAc extractions since it was able to extract even the "difficulty available" K. Although the soils contained low exchangeable K, most of the soils with the exception of La Paz, Tarlac, and Buenavista, have high buffering capacities (PEC). Significant correlation between pack and clay content (x = 0.81) and CEC (r = 0.87) were recorded. The Q/I relations of the soils used in the greenhouse experiment (Maligaya I and San Marnasl I) redetermined after K addition and after the soils have been depleted of K by crop uptake were transposed vertically in the direction expect

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Holdings ( 1 )
Title notes ( 4 )

Holdings
Item type	Current library	Collection	Call number	Materials specified	URL	Status	Notes	Date due	Barcode
Theses / Manuscripts	Ladislao N. Diwa Memorial Library Theses Section	Non-fiction	631.4 B29 1988 (Browse shelf(Opens below))		Link to resource	Room use only	T-1362		00002282

Thesis (M.S. - - Soil Science) University of the Philippines, College, Laguna.

Includes bibliographical references.

BASILIO, PEARL R., University of the Philippines at Los Banos, October, 1988. Potassium Status and Exchange Characteristics of Some Lowland Soils in Luzon. Major Professor: Dr. Genaro 0. San Valentin

The study was conducted to evaluate the potassium (K) status and exchange characteristics of ten soils representing important lowland areas in Luzon. An inventory of the K content of the soils was made using the following extracting solutions: hydrogen fluoride (HF) for total K, sodium tetraphenylboron (NaTPB) for nonexchangeable K and ammonium acetate (MNH,0Ac) for exchangeable K. Quantity/Intensity (Q/I) parameters derived from the Q/I curves were tested against K availability indices to assess its value in characterizing K status. Q/I data described K status by reJating the intensity (1) of K to the amount (Q) of labile K in the soil.

A greenhouse experiment was conducted to determine the influence of K addition and K uptake on the Q/I parameters of selected lowland soils and at the same time assess their K supplying capacity. A high soil to plant ratio was used to exhaust available K supply in a_ short period. Right of the soils studied contained 2:1 expanding type of clay minerals Bantog and Tarlac were dominated by vermiculite. X-ray diffraction patterns of the sand fractions of all the soils showed the presence of quartz and feldspars. The soils varied in their chemical characteristics which include pH, cation exchange capacity, organic matter content, changeable K, NaTPB-extractable K, ark., Z\K9 and
pEck,

The exchangeable K contents (NH4OAc extractable K) of eight soils were found to be below the satisfactory level of exchangeable K for rice. Only San Manuel T and Rantog had an exchangeable K level higher than 0.2 me/100g. Significant correlations were found between exchangeable K and aRK, (x = 0.77) and /\K° (r = -0.96). Sodium tetraphenylboron extractions gave higher values for K than NH4QAc extractions since it was able to extract even the "difficulty available" K.

Although the soils contained low exchangeable K, most of the soils with the exception of La Paz, Tarlac, and Buenavista, have high buffering capacities (PEC). Significant correlation between pack and clay content (x = 0.81) and CEC (r = 0.87) were recorded.

The Q/I relations of the soils used in the greenhouse experiment (Maligaya I and San Marnasl I) redetermined after K addition and after the soils have been depleted of K by crop uptake were transposed vertically in the direction expect

Submitted to the University Library 01/07/1994 T-1362