The observation of rhizosphere to reflect the nutritional conditions by image analysis and the application of the method to diagnosis.

We have established an observation method of rhizosphere to reflect the nutritional conditions using by both a new plant root box made of phenolic resin form for developing whole root systems in water culture and image analysis.The root box allowed better visualization of changes in pH and the distribution of nitrate and phosphorus by image analysis in a representative whole root system。The pH values were detected with pH indicators，nitrate and phosphorus concentration with color reagents，sprayed onto profiles of the root system.We observed acidification of the medium in the root system of wheat grown1/4(NH I D24ii D2-N/NO ID23 IED2-N)medium until 12h，while at48h the pH rose agto 6.0 and higher.This rise was accompanied by a decrease in the nitrate concentration at 24and48h.In contrast，the pH increased around the roots of chinese cabbage with time，while nitrate decreased，suggesting relationship between rhizosphere pH changes and preferential cation/anion uptake of plants.Also we observed the acidification of rhizosphere with iron and phosphorus deficiency，and by coexisting insoluble phosphate salts(AlPO I D24锡D2).In addition，we evaluated the root activity under the different fertilized conditions by image analysis of root color in stead of the judgment by eyes.The method we established can be applied to the nutritional diagnosis of plants.

We have established an observation method of rhizosphere to reflect the nutritional conditions using by both a new plant root box made of phenolic resin form for developing whole root systems in water culture and image analysis. The root box allowed better visualization of changes in pH and the distribution of nitrate and phosphorus by image analysis in a representative whole root system. The pH values were detected with pH indicators, nitrate and phosphorus concentration with color reagents, sprayed onto profiles of the root system.We observed acidification of the medium in the root system of wheat grown 1/4(NHィイD24ィエD2-N / NOィイD23ィエD2-N) medium until 12h, while at 48h the pH rose again to 6.0 and higher. This rise was accompanied by a decrease in the nitrate concentration at 24 and 48h. In contrast, the pH increased around the roots of chinese cabbage with time, while nitrate decreased, suggesting relationship between rhizosphere pH changes and preferential cation / anion uptake of plants. Also we observed the acidification of rhizosphere with iron and phosphorus deficiency, and by coexisting insoluble phosphate salts (AlPOィイD24ィエD2 and FePOィイD24ィエD2).In addition, we evaluated the root activity under the different fertilized conditions by image analysis of root color in stead of the judgment by eyes.The method we established can be applied to the nutritional diagnosis of plants.