Effect of Jellyfish fertilizer on Seedling Growth and Soil Properties (第43回大会特集)
The excessive increase of jellyfish swarms could threaten the fishers and the marine food chain. The aim of research was to evaluate the potential benefit of the jellyfish as a fertilizer for different trees. The greenhouse experiment was conducted at Kutan, Chuncheon, South Korea using two tree species. Jellyfish was applied to soil before planting at different application rates (1.6, 2.7, 5.5, and 11.1 g/kg). Generally, the addition of jellyfish fertilizer increased soil moisture contents. It is concluded that low application rate of jellyfish fertilizer increased soil moisture and nutrient contents, consequently, enhancing the seedling growth.
Effect of long-term organic fertilizer application on soil microbial dynamics
5 cfu/g. The highest bacterial and fungal counts were recorded during 21 - 52 weeks (S2) of fertilizer application, while the lowest counts were recorded during the 0 - 4 and 104 - 260 weeks of fertilizer application. Several bacteria isolated belonging to six genera including Bacillus , Erwinia, Pseudomonas , Micrococcus , Proteus, and Klebsiella were observed in this study, while the fungal isolates included members of the genera Aspergillus , Penicillium , Rhizopus and Fusarium . Bacillus , Proteus and Aspergillus and were observed to have increased in number within the period of the different treatments, in comparison with Erwinia , Klebsiella , Micrococcus and Fusarium genera which decreased in population. We conclude that the organic fertilizer used in the present study was well tolerated by the native soil micro flora since there were no discernable changes in the overall population of the resident soil bacteria and fungi. Besides their value in restoring soil nutrient and structure, incorporation of organic fertilizer could lead to the control of some soil borne bacterial and fungal pathogens.
A rapid method for assessing sodicity hazard using a cation exchange membrane
Abstract Ion exchange reactions which occur between the soil and synthetic resin surfaces have been used to approximate nutrient movement and uptake by plants. Similar exchange principles govern the proportion of sodium which will exist on the soil exchange. This study investigated the use of a cation exchange membrane (CEM) in estimating the sodicity of soil. For soils ranging in salinity from non to extremely saline, the saturated paste extractable sodium was not well related to the CEM exchangeable amounts. However, the sodium adsorption ratio (SAR) was closely related to the CEM exchangeable Na ( r 2 = 0.95), suggesting a link between Na on the soil exchange complex and that adsorbed by the CEM. The factors which control the ion exchange dynamics of the soil exchange complex appear to similarly control cation exchange onto the CEM. This premise was used as the basis for a simplified measure of exchangeable sodium percentage (ESP). Sodium occupying the CEM, expressed as a percentage of the entire CEM capacity, showed a one to one correspondence with ESP measured using standard methods ( r 2 = 0.91). Exchange membranes, therefore, offer a simple and rapid method of assessing soil sodicity.