A Decision Support System for Rice Cultivation on Acid Sulfate Soils in Malaysia

Ameliorative steps to put acid sulfate soils into productive use can be organized by a decision support system. The model uses microeconomic analysis to get an optimal rate of lime and fertilizer in maximizing profit. A glasshouse experiment was conducted on an acid sulfate soil in Malaysia to get the potential yield. A field trial was conducted for validation purposes. The recommended rate of fertilizer application of 150-200 kg ha-1 N. 20-30 kg ha-1 P and 150-200 kg ha-1 K were applied during the critical stage of the rice growth. Field Adjusting Factor (FAF) of 0.40 has been found and this was used to analyze the production function. Using TableCurve 3D software. an equation for production function was established. Validation using experimental data showed that the equation has a good capability. shown by the value of p>0.2 (t-test) and MEE of 2%. The model. named as RiCASS (Rice Cultivation on Acid Sulfate Soil) was developed and successfully simulatedthe maximal profit under 4 different scenarios. The recommended rate of lime (GML) was 6.5 t ha-1 for maximal profit and 2.5- 3.0 t ha-1 for the farmers, practice. Keywords: Acid sulfate soil. decision support system. field adjusting factor. lime. ric

Alleviating an Acid Sulfate Soil Cultivated to Rice (Oryza sativa) Using Ground Magnesium Limestone and Organic Fertilizer

Rice yield on acid sulfate soils in Malaysia is very low, presumably due to AI and/or Fe toxicity. This study wasconducted to ameliorate an acid sulfate soil in the Kemasin-Semerak Integrated Agricultural Development Project, located in Kelantan, Peninsular Malaysia, for rice cultivation. Rice variety, MR 219, was used as the test crop. Treatment included the use of various rates of ground magnesium limestone (GML), with or without an organic fertilizer. This acid sulfate soil had an initial pH of < 3.5 at depth below 45 cm. Exchangeable AI in the soil was high, especially in the subsoil. The first crop of rice was disturbed by floods. The result for the 2"d crop showed a promising trend; applying 4 t GMUha in combination with an organicfertilizer, the topsoil pH had increasedfrom 3.95 to 4.21, increasing the exchangeable Ca and Mgfrom 1.58 and 0.48 cmol/kg soil to 2.57 and O. 79 cmol/kg soil, respectively. In this treatment, the rice yield was 7.5 tlha, which was much higher than that produced by farmer's practice of about 2 tlha. The increase in yield was due to the combined effects of increasing pH and exchangeable Ca and Mg and of lowering AI and Fe concentration in the soil solution

Design procedures of reinforced concrete framed buildings in Nepal and its impact on seismic safety

The present paper analyses the design procedure and its impact on seismic safety of the structures. For this, a representative reinforced concrete frame building (WDS) is designed and the results are compared with similar buildings detailed with: i) Current Construction Practices (CCP); ii) the Nepal Building Code (NBC) and iii) the Modified Nepal Building Code (NBC+) recommendations. The seismic performance evaluation is done with global strength, inter-storey drift and displacement of the structures. Likewise, the sensitivity of the structural and geometrical parameters of the RC frame building is studied through nonlinear analysis. The study parameters considered for parametric analysis are column size, beam size, inter-storey height, bay length, bay width, and compressive strength of concrete. The results show that the influence on the structural behaviour, particularly by variation in column size and inter-storey height. Additionally, the influence of the seismic zone factor on reinforcement demand of the structure is studied. The result shows that structures designed for high to medium seismic hazard demands double the reinforcement in beams compared to structures in low seismic zone