The application of organic matter to arable land is important in promoting soil fertility. Excessive application of organic matter, however, causes adverse effects on the nutrient condition of the soils and ground water pollution. We propose subsoil application of cattle manure composts (CMC) to strongly acidic andisols in which elongation of crop roots are inhibit, since CMC have ameliorate ability of acid injury soil. It's probable that the CMC have a slowly decomposing character when mixed with water treatment residuals (WTR) containing aluminum (Al). Aluminum cattle manure composts (AlCMC) having a slowly decomposing character were expected to have an organic sequestration effect when they were applied to subsoil. This study was carried out to confirm the nitrogen and carbon mineralization characteristics of A1CMC, and also the effect of AlCMC application on soil chemical properties and sorghum growth. 1) Incubation at 50℃ after mixing CMC with WTR accelerated oxidation of manganese ion (Mn^<2+>) which is otherwise harmful to plants. Exchangeable manganese decreased to one-tenth of the initial amount over ten days. The available phosphorus in CMC was fixed by Al contained in the AlCMC (containing 50% WTR) and decreased to 33% of that in CMC. Exchangeable potassium in CMC was not fixed by AlCMC. 2) The carbon dioxide (CO_2) emission from CMC mixed with WTR was compared with the sum of CO_2 emissions from unmixed CMC and WTR. When the mixing rate of WTR : CMC was 1:1 or 1:2, CO_2 emission decreased to 87% or 71% respectively of that from the unmixed treatment after 86 d. The nitrogen mineralization in the 1:1 mixing treatment after 70d decreased to 75% in comparison with the unmixed treatment. 3) The acid soil used in the pot culture experiment was ameliorated. Soil pH increased to more than 5.7. The available phosphorus after the pot experiment was lower in the AlCMC treatment compared with that of the CMC treatment. The exchangeable manganese was sufficiently low to prevent harm. The cation exchange capacity increased after treating with Al compost. 4) The applications of the AlCMC increased the dry matter of sorghum compared to non-treated compost, owing to soil acidity amelioration. Sorghum growth in the AlCMC treatments was equivalent to that of CMC treatment. In conclusion, the rate of the mineralization of carbon and nitrogen, and the amount of available phosphorus of CMC was suppressed by mixing with WTR. Application of AlCMC to soil improved soil acidity, cation exchange capacity and soil nutrient status.

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Nitrogen flows five-year intervals during for the period from 1982 to 1997 were estimated by "Domestic Nutrition Balance Estimation System" that represents the flow of production-processing-consumptiondisposal of foods and feeds in Japan. The trend over this period can be summarized as follows : 1) Total nitrogen discharge to the environment (total annual consumption) recorded the peak at 1,706 Gg in 1992, and it slightly decreased in 1997. On the supply side, domestic production of nitrogen has been decreasing since 1987, and the shortage is supplied from continuously increasing import. 2) As regards the increase of import in the "Livestock industry", the relative importance of feed imports decreased, while that of imports in the form of products such as dressed carcasses and unprocessed milk increased. In addition, trends of the increasing dependence on foods from overseas are recognized in every phenomenon, such as an increase in import ratio in the supply to the "Food processing" and a decrease in "Crop residues" in domestic production. We examined the accuracy of the estimation of discharge from "Human food consumption" and "Livestock industry", which accounted for approximately 86% of total discharge to the environment in 1997 by evaluating the goodness of fit to the relevant organic waste data. Out of the nitrogen discharge from "Human food consumption" (643 Gg), 601 Gg was considered to be discharged from domestic wastewater. The difference between this figure and a value of 543 Gg estimated using the nitrogen basic unit in sewage was about 10%. In addition, the nitrogen discharge from livestock excreta was estimated at approximately 731 Gg out of that from "Livestock industry" to the environment. This figure was equal to a value of 721 Gg estimated using the nitrogen basic unit in excreta of domestic raising livestock in 1999.

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Nondestructive surface chemical analysis using X-ray photoelectron spectroscopy (XPS) was conducted to clarify the effect of outer-surface chemical composition of soil aggregates on the water repellency of forest soils. The ratios of carbon to oxygen (C/O) and nitrogen to oxygen (N/0) were higher on the outer surface than in the interior of soil aggregates, indicating that soil organic matter tends to accumulate on the outer surface of aggregates. The surface C/O ratio determined by XPS was not necessarily proportional to the total carbon content (TC) measured by the thermal combustion method. TC did not sufficiently explain the degree of soil water repellency expressed by the ethanol percentage (EP) (R^2=0.34), whereas the surface C/O ratio by XPS sufficiently explained water repellency (R^2=0.74). The shapes of C1s spectra differed between strongly water-repellent soils under Japanese cypress and weakly water-repellent soils under deciduous broad-leaved trees. Soils with strong water repellency had C1s spectra rich in components of small chemical shift (small binding energy). These components correspond to carbon of nonpolar functional groups (C-C or C=C), i.e., not bound to atoms with high electronegativity, such as oxygen or nitrogen. The ratio of carbon with a small chemical shift to oxygen on the outer surface of soil aggregates could be regarded as a strong controlling factor of soil water repellency (R^2=0.86).

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Eutrophication has been a serious environmental problem all over the world. Nutrients such as nitrogen and phosphorus discharged into enclosed water bodies are major factors in eutrophication. The purpose of this study is to characterize the removal of ammonium and phosphate from food industrial wastewater with aluminosilicate. In batch experiments, adsorption kinetics of NH_4^+-N were described by the pseudo second order kinetic model. The adsorption isotherm for NH_4^+-N fit the Langmuir plots with 8.21mg-N g^<-1> adsorption maximum and Henry plots was suitable for PO_4 adsorption. The NH_4^+-N adsorption onto aluminosilicate was ion exchange reaction between Na^+ and NH_4^+. The removal percentage of NH_4^+-N from 50 mL of 5 mg-N L^<-1> standard solution was greater than 85% at the initial pH 4-10. The NH_4^+-N removal decreased in the presence of the competitive ions and interference with competitive ions followed in the order of Ca^<2+> > Mg^<2+> > K^+ > Na^+. The removal percentage of PO_4 from 50mL of 5mg-PO_4 L^<-1> standard solution was highest at pH 3.7 and low values at pH < 1.5 and 5.6 <. However, the removal percentage of PO_4 from 50mL of 5mg-PO_4 L^<-1> mixed solution contained Ca^<2+>, Mg^<2+>, NH_4^+ was 28.4% and the PO_4 in food industrial wastewater was removed well even if the pH value was 5.9-8.0, which removal mechanism still remains to be solved. The removal percentages of NH_4^+-N and PO_4 from food industrial wastewater were 20.6-74.3% and 73.5-80.0%, respectively.

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A gray Terrestrial Regosol called "Jagaru" that corresponds to Udorthent in the Soil Taxonomy is widely distributed in the southwestern islands of Japan. Jagaru is a heavy-textured smectitic soil and shows problematic physical properties such as severe hardening by air-drying. In order to improve the physical properties, the effects of clinker ash, which is the coarse fraction of coal ash, on the properties of Jagaru, and growth and mineral composition of lettuce were investigated. Physical and chemical analysis of clinker ash revealed that it is a mixture of grains of various particle sizes and chemical composition. Total elemental composition of bulk clinker ash was similar to Jagaru. Application of clinker ash increased available water content and reduced solid ratio, bulk density and the strength of air-dried soil blocks of Jagaru, and clinker ash was more effective for the improvement of these physical soil properties than river sand of the same quantity. On the other hand, pot cultivation experiments showed that the application of clinker ash does not increase the yield of lettuce, and heavy application of the ash caused a slight reduction of yield. The yield was remarkably small in the plot that was not watered before planting in order to reduce the salinity caused by ash. According to the effect of clinker ash for improvement of the physical properties of soil greater than usual sand and the inverse effect for lettuce growth and cost for the transportation of ash, a suitable amount of application was assumed to be around 10% of topsoil which corresponds to 240 t ha^<-1>. No problematic effect such as heavy metal accumulation in the plant was caused by ash application.

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In order to examine a possible uptake of protein-like organic nitrogen in a soil by tea plants (Camellia sinensis L.) and 6 vegetables species (cucumber (Cucumis sativus L.), chingensai (Brassica campestris L.), leaf lettuce (Lactuca sativa L.), broccoli (Brassica oleracea L. var. italica), spinach (Spinacia oleracea L.) and maize (Zea mays L.)), HPSEC analysis of the xylem saps collected from these 7 plants was conducted. One series of these 7 plant species were grown on a pot filled with soil supplemented with organic matter, while another series of 7 plant species were grown on solution culture or vermiculite-filled pot with chemical fertilizer only. Our findings were as follows : The concentration of mineral nitrogen found in the xylem saps collected from the 6 vegetables in plots with chemical fertilizer were higher than in plots with organic matter. This result showed that the uptake of mineral nitrogen in a soil of these 6 vegetables in plots with chemical fertilizer were higher than in plots with organic matter. Substances with the same molecular weight as protein-like organic nitrogen (estimated molecular weight 4000-5000 Da) extracted with water and potassium chloride in soils were detected from the xylem saps of the 6 vegetables and the tea plants by HPSEC analysis. Interestingly, the HPSEC peak height of same substances of protein-like organic nitrogen from the xylem saps of 6 vegetables and the tea plant (cv. Saemidori) were higher in plots with organic matter than in plots with chemical fertilizer. Moreover, the same HPSEC peak of substances of protein-like organic nitrogen in the xylem saps collected from the tea plants (cv. Yabukita and Yutakamidori) in the general manuring practice, which were cultivated in the tea plantation managed at Chiran region in Kagoshima Japan, were also detected. These results indicated that there was a possibility of a direct uptake of protein-like organic nitrogen in a soil not only by vegetables but also by tea plants in addition to mineral nitrogen in a soil.

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In the drip-application (fertigation) culture, plant nutrients are supplied both from nutrient solution and from soil media. In this study, the effect of phosphorus contents in the soil or in the nutrient solution on the growth of melon (Cucumis melo) and tomato (Lycopersicon esculentum) was examined. The soil used in this study was allophanic andosol which had high phosphorus fixation capacity. 1) When the Truog-P content was approximately 200 mg P_2O_5 kg^<-1> or more in the soil, the yield of melon (one fruit per plant) and tomato (in the fifth cluster stage culture) was almost the same regardless of the phosphorus contents in the nutrient solution. 2) When the Truog-P content was approximately 1000 mg P_2O_5 kg^<-1> or more in the soil, the absorption of phosphorus in melon and tomato was almost the same regardless of the phosphorus contents in the nutrient solution. 3) In the soil highly enriched with the phosphorus as frequently observed in farmers' greenhouse soils, there is no need to supply any further phosphorus in the nutrient solution because its recovery is very low. Curtailment of phosphorus is certainly helps to make the soil phosphorus status more appropriate and to reduce the fertilizer cost for the farmers. 4) As to the nutritional diagnostic criteria for the phosphorus concentration, we propose 150 mg P L^<-1> in the sap of melon petioles collected at the thinning in the spring-summer season, and 200 mg P L^<-1> in the sap of tomato petioles just under the first cluster fruits of 2-3 cm diameter in the fifth cluster stage culture in autumn-winter season. 5) Phosphorus concentration of the petiole sap reflected the phosphorus nutritional status very well. Therefore, by adjusting the nutrient composition of the solution with the soil testing before planting and with petiole sap diagnosis during the plant growth periods, we can achieve the optimized fertilization in the drip-application culture.

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Rice plants accumulate iodine and display a physiological disorder due to the toxicity of iodine. The disorder is called "Akagare" disease. The relationship between soluble iodine in soil and "Akagare" disease of rice plants was examined. Seedlings of rice plants 20 d after germination were grown in soils rich in iodine for 29 d. In addition, the difference in response to "Akagare" disease among varieties of rice plants was compared. 1. Soluble iodine was evaluated by incubating a mixture of 2 g of soil and 10mL of 2.8×10^<-2>mol L^<-1> glucose solution for 10 to 20 d at 30℃. The concentration of iodine absorbed by rice plants correlated positively with the concentration of soluble iodine in soil. 2. Height and dry weight of shoots of rice plants decreased with the increase in the concentration of iodine in rice plants due to the toxicity of iodine. 3. The symptom of "Akagare" disease became remarkable when the concentration of iodine in rice plants (shoots) was over 300 mg kg^<-1> (dry weight basis). Iodine concentration in rice plants exceeded 300 mg kg^<-1> when the concentration of soluble iodine in soil surpassed 6-8 mg kg^<-1>. From these results, it was indicated that the possibility of incidence of "Akagare" disease was predicted on the basis of the concentration of soluble iodine in soil. 4. A remarkable difference in response to "Akagare" disease among varieties of rice plants was recognized.

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We examined effects of SO_4^<2-> and Cl^- concentration in fertilizers on NO_3^- concentrations in spinach (Spinacea oleracea L.) and ching guang juai (Brassica chinensis L.) in the isolation floor cultivation. By combining ammonium sulfate, ammonium chloride, urea or rapeseed meal as N fertilizer and potassium sulfate or potassium chloride as K fertilizer, various treatments were prepared in this experiment. Multiphosphate was uniformly applied as P fertilizer. They were applied as basal fertilizers at the rates of 15g of N per m^2, 6.5g of P per m^2, and 12.5 g of K per m^2. The main results obtained were as follows. 1) There were no differences in yield and nitrogen uptake of spinach and ching guang juai among the treatments. Nitrate concentration in plants decreased with the increase in the amount of Cl^- applied to the soil with highly negative correlation. In contrast, there was no relationship between NO_3^- concentration in plants and the amount of SO_4^<2-> applied to the soil. These findings indicate that application of chlorides to the soil lowers NO_3^- concentration in leaf vegetables without any effect on their growth. 2) As there was no significant difference in NO_3^- concentration in plants between ammonium sulfate and rapeseed meal applications, the effect of the form of fertilizers, inorganic or organic, was concluded to be minor to that of anions in fertilizer, SO_4^<2-> or Cl^-, on NO_3^- concentration in leaf vegetables.

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[in Japanese]

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