Browsing by Author "Mohinder Singh, M."

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    A Thermodynamic Assessment of the Nutrient Status of Malayan Soils Quantity-Intensity Measurements for Potassium Using Calcium Chloride Equilibriation
    (1968) Mohinder Singh, M.; Tan, K.T.; Pushparajah, E.; Talibudeen, O.
    Quantity /Intensity (Q/I) relationships for potassium status of soils were determined in nine acid soils of Malaya which are known to have widely differing K-status and on which rubber Is commonly grown, by the calcium chloride equilibriation procedure of BECKETT. Quantity. Intensity and Buffer Capacity values derived from these Q/l relationships did not give better relation with the status of soil, as indicated by greenhouse cropping by Pueraria. than the conventional acid-extractable value. The best assessment parameter appeared to be a Buffer Capacity value (B. C. cropping), obtained from greenhouse cropping data and the laboratory measured intensity, although intensity, when taken alone is the poorest Indicator of soil K status as assessed by greenhouse cropping by Pueraria.
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    Thermodynamic Assessment of the Nutrient Status of Rubber-Growing Soils
    (1969) Mohinder Singh, M.; Talibudeen, O.
    Schofield s thermodynamic concepts of intensity and quantity were used for measuring the potassium and phosphorus status of Malayan rubber-growing soils. It was shown that for acid soils in Malaya, intensity and quantity measurements need be done using aluminium as the reference ion instead of calcium used elsewhere. For phosphorus, intensities were measured in dilute ammonium chloride solutions instead of calcium chloride solutions used elsewhere and quantities were measured by isotopic exchange. l These thermodynamic indices and the conventional indices of acid-extractable and exchange-. able values for potassium, and total and available indices for phosphate, which are in current routine use, were related to uptake by Pueraria phaseoloides in the glasshouse. This showed that for assessing the potassium status of Malayan soils, the buffer capacity value obtained from the slope of the quantity! intensity relationship curve was better than the conventional acid-extract-able and exchangeable values currently used for determining the fertiliser requirements of rubber. For phosphorus, both conventional and thermodynamic quantity indices related directly to glasshouse cropping. More work is however necessary for a systematic correlation.