Use this URL to cite or link to this record in EThOS:
Title: A study of Bangladesh tea soils, with particular reference to the efficiency of phosphatic fertilizers
Author: Golam Kibria, A. K. M.
Awarding Body: University of Aberdeen
Current Institution: University of Aberdeen
Date of Award: 1981
Availability of Full Text:
Access from EThOS:
aThis study was undertaken to investigate the possibility of substituting the currently used and more expensive superphosphate (TSP) by rock phosphate (RP) as a phosphatic fertilizer for tea cultivation. Five top soil samples and four corresponding subsoils were selected from the tea-growing areas of Bangladesh. These soils were extremely acid and poor in nutrient status, with moderate to high P adsorption capacities. Phosphatic fertilizer dissolution and incubation studies showed that RP is about 70% and 50% effective, respectively, in releasing exchangeable P as RP. Incubation of a Scottish sub-soil showed that RP was 40% as effective in releasing exchangeable calcium. Two series of glasshouse trials were designed to run consecutively, using rye (Secale cereale) as test crop. Phosphate was applied as Gafsa RP and TSP at rates of 0, 50, 100, 200 and 300 mg P kg⁻¹ with N and K as a basal dressing in the first experiment; N and Mg were applied in the second, with no further P application. In the first experiment, TSP gave higher total dry matter yield and P uptake than RP, whereas in the second experiment RP gave decidedly higher yield and uptake than TSP. The efficiency of RP relative to TSP in increasing total P uptake at corresponding levels of application ranged from 60% to 108%, increasing to 80% to 130% in the second experiment. In both experiments, the RP treatments increased the pH and exchangeable calcium content of the soil more than TSP, whereas resin-extractable P was higher after TSP treatments. The results lend encouragement to the extension of this work to field trials with tea, in the expectation that RP will not only increase yields but, through its residual value, increase soil fertility, providing considerable commercial and economic benefit.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available