Nitrogen is an essential nutrient for plant growth. When the plants have been grown for a long-term effect to decreased nitrogen in soil and insufficiency of the plant growth. One biological method for increasing the nitrogen content in soil is utilize of free nitrogen-fixing bacteria Azotobacter. Therefore the objective of this research was to search natural material suitable for Azotobacter fixation. The 10 natural materials were observed physical structure and investigated the ability of natural materials for Azotobacter fixation. The results showed that water hyacinth and bagasse stalks were fixed the Azotobacter of 2.43x108 and 1.94 x108 CFU per gram of each natural material respectively. After that the selected fixed Azotobacter of water hyacinth and bagasse stalks were studied the growth of Brassica Chinensis. This experiment was designed to 4 treatments. The first treatment was mixed of water hyacinth stalks and the Azotobacter. Second treatment was mixed of bagasse stalks and the Azotobacter. The third treatment was the Azotobacter only. The last treatment was soil only. The results indicated that the average of plant growth include height leaf number root length fresh weight and dry weight of the mixed of water hyacinth stalks and the Azotobacter had significantly higher growth rates than other treatments. The total nitrogen was also increased 1.4 fold in the soil. All results suggest that the water hyacinth stalk is alternative for the fixation of the free nitrogen-fixing bacteria Azotobacter as induce nitrogen in the soil and plant growth promotion.

The objectives of this research were to study the growth rate of microbial sludge in the fermented juice and to study the efficiencies of fermented juice and melodies on Fairy Rose growth. In the experiments the growth rate of microbial sludge was analyzed with 10 parameters for 4 weeks. Moreover the Fairy Rose was divided into 2 groups used and non-used the fermented juice. Each experimental group was tested with 3 types of melodies including jazz classical and Mozart. All experiments were set 3 replications by the total number of 24 Fairy Roses. The growth of the Fairy rose was analyzed by considering the number of leaf Height length of root and mass. The experimental results showed that the growth of microbial sludge in fermented juice was good and produced microbial sludge in fermented juice approximately 1063 ±158 mg/L on average. The Fairy Rose more growing with water and fermented juice. The number of leaves was 144±11 leaves in average Height was 30±1 cm in average Length of root was 38±8 cm in average and weight of Fairy Rose at the end of experimentation was found 400 g in average. In the case of melody affected Fairy Roses growth was classical. The growth of fairy roses found that the number of leaves was 143±6 leaves in average height was 29±1 cm in average Length of root was 34±1 cm in average and weight of Fairy Roses at the end of experimentation was 93 g in average

The purposes of this research were to assess the combined phytotoxicity of glyphosate and carbendazim which were normally used as herbicide and fungicide contaminated in soil as 100 – 1000 mg/kg on seedling growth of ridge gourd. Both of glyphosate and carbendazim were toxic to shoot and root growth of ridge gourd seedlings. The 50% effective concentration (EC50) on shoot length root length root fresh weight and shoot dried weight of ridge gourd seedlings for glyphosate were 669.4 413.0 574.5 and 241.4 mg/kg respectively whereas for carbendazim were >1000 357.8 >1000 and 71.4 mg/kg respectively. Co-contamination between glyphosate and carbendazim seemed to be antagonistic effect. Both of glyphosate and carbendazim at all concentration were not toxic to chlorophyll content in cotyledon of ridge gourd seedlings.

Use of synthetic surfactant is another choice to increase efficiency of polycyclic aromatic hydrocarbon (PAH) phytoremediation in soil. In this study the toxicity of soil contaminated with anthracene and fluoranthene at total concentration as 0 200 and 800 mg/kg in combination with 2 synthetic surfactants that were triton x-100 and tween 80 at concentration as 0 1 and 10 times of critical micelle concentration (CMC) on seedling growth of Hibiscus sabdariffa and Mirabilis jalapa. Both synthetic surfactants were watered separately on day 13 after inoculation and seedling growth were measured on day 20 after inoculation. The result shown that both H. sabdariffa and M. jalapa could grow in soil contaminated with anthracene and fluoranthene at all concentrations in combination with both synthetic surfactants. Tween 80 at 1 time of CMC were the least toxic to H. sabdariffa while toxicity of all surfactants on M. jalapa were not different. Decrease of plant growth depended on the increasing of PAH concentration in soil. With these reasons both plants were possible to use for PAH phytoremediation at total concentration 200 mg/kg in combination with synthetic surfactant

The effects of plant growth regulators alone or in combination on Hexachlorocyclohexane (HCH) phytotoxicity were studied. Waxy corn seeds were immersed in different plant growth regulators that are 1) 2 mg/l Indolebutyric acid (IBA) 2) 2 mg/l Thidiazuron (TDZ) 3) 2 mg/l Gibberellic acid (GA3) 4) 1 mg/l IBA + 1 mg/l TDZ 5) 1 mg/l TDZ + 1 mg/l GA3 and 6) 1 mg/l IBA + 1 mg/l GA3 then sawn in 30 mg/kg HCH-contaminated soil or non-contaminated soil for 10 days. All plant growth regulators could enhance shoot and root dried weight of waxy corn seedlings in non-contaminated soil. Only 2 mg/l GA3 could enhance root length of waxy corn seedlings in non-contaminated soil. In HCH-contaminated soil only 2 mg/l TDZ could increase shoot dried weight of waxy corn seedlings. Also 2 mg/l IBA or 1 mg/l IBA and1 mg/l GA3 could increase root fresh weight of waxy corn seedlings. The exposure with HCH in soil did not affect to shoot and root tissue even though the growth of shoot and root were inhibited. However the exposure with HCH and receive exogenous plant growth regulator induced aerenchyma formation in cortex and pith of waxy corn root.