The phosphate supply patterns of some Philippine soils with high and low phosphorus contents

Date

1963

Abstract

This work was undertaken to study the phosphate supply pattern of soils and the effects of the application of phosphorus on the pattern, yield of dry matter of the plants and their phosphorus contents.

In general the patterns can be grouped into two categories:

1. Gradual decrease in phosphorus concentration. This was shown by the phosphorus concentration in the: (a) solution obtained successively at weekly intervals from the soil with growing mango plants, (b) leachates collected from soils at 30 minute intervals and (c) the rice plants by tracer technique.

2. Zig-zag pattern. The pattern was derived by determining phosphorus in the solution from the soil with (a) rice under lowland condition and (b) second crop of mungo; (c) equilibration technique and corn and rice plants harvested at different ages.

For soil testing laboratory the continuous leaching method is most practical; for research work the soil- solution-plant method or the tracer technique may be given preference.

Lipa lowland and upland which are both non-responsive to P-application maintained higher levels of phosphorus compared to the other six soils which were responsive to the addition of phosphorus, showed lower concentration.

The effect of the addition of phosphate on the phosphorus concentration in the soil solution varied with the original phosphorus status of the soils and water regimes. It increased both the dry matter and the phosphorus content of the plants in the p-responsive but not in Lipa soils.

The tracer technique enhanced the determination of available soil phosphorus and the amount of added phosphate absorbed by the plant at different stages of growth.

Liming (GaCO3) Antipolo and Palawan upland soils helped control the physiological disease of mango plants. It however did not increase the yield of dry matter or the phosphorus uptake.

Liming (GaCO3) or adding gypsum failed to augment the dry matter or the phosphorus content of the rice plant.

On the whole, the result give a picture of the phosphate supply pattern of the soils, which can be helpful in predicting the phosphorus requirements of these soils and the corresponding management practices.

Document Type

Dissertation

Degree

Doctor of Philosophy in Soil Science

College

Graduate School (GS)

Adviser/Committee Chair

Nicolas L. Galvez

Language

English

LC Subject

Soils--Phosphorus content, Soils--Philippines

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 996 1963 S72 M3

Notes

Doctor of Philosophy (Soils)

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