Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Transformation of Different Phosphatic Fertilizers in Some Soils of East Pakistan at Field Moisture Capacity and Waterlogged Condition

Aminul Islam
Department of Soil Science, Dhaka University, Dhaka, Bangladesh

T. H. Khan
Department of Soil Science, Dhaka University, Dhaka, Bangladesh

Abstract/ Executive Summary:

The three fertilizers-ordinary superphosphate, triple superphosphate and diammonium phosphate added to soils were converted into NH₄-CI soluble, aluminium, iron and calcium phosphates more or less in the same way and in similar proportions. The highest percentage of added phosphorus was recovered as aluminium phosphate at both moisture levels. In 12 weeks of incubation at field moisture capacity, transformations of NH₄-Cl-soluble, aluminium and calcium phosphates (in acid soils only) to iron phosphate and under submerged condition, iron and NH₄- CI-soluble phosphates to aluminium phosphates were noted.

Keywords: Soil, Waterlogged, Fertilizer, Phosphatic

Location:

Start Date:

End Date:

Program Area: Crop-Soil-Water Management

Commodity: Land development productivity

Objectives:

To study. (i) the effect of different sources of phosphatic fertilizers on relative proportion of different discrete forms of, inorganic phosphates, and (ii) the percentage of applied phosphatic fertilizers converted to various forms of inorganic phosphates and the relative changes of these differentially fixed phosphates with time.

Methodology:

Soil samples representing 0-6" depth and differing in pH were collected from Savar (Dhaka), Pak Tobacco Experimental Station (Rangpur), Benerpota farm, (Khulna); Amritapur (Comilla) and Madaripur. Three phosphatic fertilizers - ordinary superphosphate (OSP), triple super phosphate (TSP), and diammonium phosphate (OAP) were included, in this study. Each phosphatic fertilizer was added at the rate of 400 lbs of P per acre to 100gms of the soils. They were thoroughly mixed and placed in glass bottles. To each pot, measured amount of water was added to bring the moisture level of the soils approximately to field moisture capacity. The bottles were corked up and kept for the transformation study. A similar experiment was also performed to study the transformation of added phosphorus at water-logged condition. In this case the soils mixed with fertilizers were kept in bottles and then submerged with distilled water to a depth of about 1 inch. Soil samples were taken at the intervals of 1, 2, 4, 8 and 12 weeks from the date of mixing the fertilizers. Samples representing each treatment analyzed for different from of inorganic phosphates immediately after sampling, by following the method of fractionation originally proposed by chang and Jackson (1957a) and later modified by Chang and Liaw (1962). The conversion percentage of the added phosphorus for a particular form of phosphate was calculated by the following equation: X = (T - B)/W x 100. Where X = % conversion for a particular form of inorganic phosphate. T= Amount of phosphate (ppm) of that particular form in the treated soil. B = Corresponding amount (ppm) of phosphate in the same soil without fertilizer. W= Amount of phosphorus (ppm) added to the soil.

Source of Information: Proc. Pak. Acad. Sci. 13 (1): 63-71, 1966

Article Link (Online Journal):

Funding Source:

1.

Budget:

Total Budget (Tk.) :

Achievement/Findings:

Under submerged condition, the conversion percentages of iron and NH₄Cl-soluble phosphates decreased with time, while those of aluminium and calcium phosphates increased. Similar results were also obtained by Hsu and Jackson (1960), Ponnarnperuma (1964) and Islam (1965). Ferrous phosphate was more soluble than aluminium and calcium phosphates (specially tri-calcium and octa-calcium phosphates). Therefore the percentage conversion of aluminium and calcium phosphates increased and those of other forms decreased. Bromfield (1960) aptly commented that aluminium phosphate did not appear to be affected by the decomposition of soil organic matter under water-logged condition and suggested that aluminium phosphate contributed the major portion of the unavailable phosphates in soils.

Knowledge Management: Journal