The purpose of this study is to produce the soil improvement materials from food waste and water hyacinth by using a dehydration process. The experiments were divided into two parts : 1) the study of the optimum temperature and time for converting food waste and water hyacinths to soil improvement materials by determining the temperatures of 100 °C 150 °C and 200°C in the periods of 1 hour 2 hours and 3 hours respectively 2) the study of nutrient content in the materials before and after mixing into the soil for 5 days. The soil used in the experiment was sampled from Sai Ma Subdistrict Nonthaburi Province. The parameters used to evaluate the ability to improve the soil quality were soil moisture pH electro conductivity total nitrogen total phosphorus total potassium and organic matter. The results showed that the optimum temperature for drying the food waste was 150°C for 2 hours and the optimum temperature for drying the water hyacinth was 200°C for 3 hours. When the materials were mixed into soil it found that the soil drainage was improved. Mixing the materials into soil could increase the pH value from 5.2 to 5.4 and increase the electrical conductivity from 0.72 mS/cm to 14.78 mS/cm. Besides the plant nutrients including Nitrogen phosphorus and potassium also increased after adding soil improvement materials.

The purpose of this research was to study the temperature of burning surf clam shell for soil quality improvement. The experiment was divided two parts 1) the study of the optimum temperature for calcium oxide production by burning 800 900 1000 and 1100 °C 2) the study of using calcium oxide to improve soil qualities of acidic soil and saline soil. The parameters used in the analysis included elements of soil particles soil moisture pH conductivity total content nitrogen phosphorus and potassium. The results showed that the optimum temperature for the production of calcium oxide was 1100 °C since it provided the highest calcium oxide content of 90 % by weight. After applying calcium oxide into acidic soil the composition of soil particles was changed from sandy clay to sandy clay loam. In contrast the soil particle was not changed but the proportion was changed in saline soil. It was also found that calcium oxide reduced soil moisture and influenced the acidity of soil by increasing the pH from 3.39 to 6.92 in acidic soil and 6.49 to 9.11 in saline soil. In addition it was found that the electrical conductivity of the soil was related to salinity. In acidic soil the conductivity of before and after inputting calcium oxide were 0.87 and 1.24 dS/m respectively. In the case of saline soil the conductivity of before and after improvement were 14.37 and 18.80 dS/m respectively. Besides it was found that the total content of nitrogen phosphorus and potassium were reduced after the experiment.