Chemical properties of irrigations, reservoirs and ground waters in Fukuoka prefecture were measured from 1986-1988, to reveal the overall status of the agricultural water quality. The numbers of places from where the waters were sampled were 53 for irrigation, 6 for reservoir and 3 for ground water. 1) In the irrigations, 76% of waters exceeded the quality standard value of T-N in agricultural water ; 23% exceeded the standard value of COD. 2) In the irrigations that stemmed from the middle and lower reaches of the Chikugo or the Yabe river, EC, COD and T-P values increased as the waters went down the rivers. Organic matters contents in the water of the lower reaches of the rivers were among the highest in Fukuoka prefecture. 3) In the irrigations and the ground waters in middle and lower reaches of the Chikugo river, the water quality declined after transplanting of rice. Fertilizer applied to the paddy fields may have run off and caused the water pollution. 4) On the outskirts of Fukuoka city, organic matters contents were high in the water of the irrigations. As positive correlations were found among COD, T-N, T-P and Cl^-, it was estimated that the water pollution by organic matters in their irrigations was caused by domestic waste water discharge. 5) Values of EC in the water of irrigations and reservoirs around the Onga river basin were generally high owing to the flowing-in of water from abandoned coal mines. 6) Values of pH in the water of reservoirs in the plains were higher than those of the surrounding irrigations. Pollution by organic matters in the reservoirs was apparent. 7) Pollution by organic matters was not found in the ground waters, though the concentrations of T-N and NO_3-N in the water were higher than those in the surrounding irrigations.

View full abstract

The combination method of fertilizer application using the ideal nitrogen absorption pattern of paddy rice and estimation of soil nitrogen mineralization was investigated in the paddy field of Gley soil and Gray Lowland soil. The combination method of fertilizer application was defined, namely, shortage for the target amounts of nitrogen absorption was supplied at each growth stage. 1) It was considered that the suitable amounts of basal application were that which had the ideal nitrogen absorption at maximum tillering stage on the common weather years. The suitable mounts of basal application strongly correlated to the amounts of available nitrogen in the soil. It means that the suitable amounts of basal application could be decided by the amounts of available nitrogen. 2) The recovery rate of soil nitrogen by rice plants was as follows : 80% in the period from panicle formation stage to full heading stage ; 60% in the period from full heading stage to maturing stage in the well-drained paddy field ; 100% in both growth stages in the ill-drained paddy field. 3) The recovery rate of topdressing application by rice plants was measured using the ^<15>N tracer experiments in the experiments field. The recovery rate was concluded at 17 and 9 days before full heading stage. The recovery rate at each growth stage was 70 and 60% in both soil types. And the recovery rate was concluded at 4 days after full heading stage, it was 60% in both soil types. 4) The estimation of amounts of nitrogen absorption by rice plants was close to the actual measurement. It was suggested that the combination method of fertilizer application was appropriate. 5) The combination method of fertilizer application was checked by the actual experiments in both soil types. The results confirmed that the combination method was appropriate.

View full abstract

Chemical characterization of Chrysanthemum coronarium roots grown under deficiency of iron nutrient conditions was examined by Curie-point pyrolysis-gas chromatography-mass spectrometry. Plans were grown in culture solution supplied with (3.0 or 0.2 ppm) iron or without iron. The roots of plant were freeze-dried and after grinding, about 1 mg samples were analyzed by Curie-point pyrolysis-gas chromatography. Pyrograms of each treatment showed a lot of peaks from 200 to 300. An analysis of many peaks was not easy visually ; therefore, the statistics cluster analysis was used for the pattern recognition. The luster analysis correctly classified the resulting pyrograms for each group. The control (standard level iron concentration) and lower level iron treatments of plant roots were closely clustered compared with iron deficiency treatment. Curie-point pyrolysis-gas chromatography coupled with multivariate pattern recognition will be a valuable method for characterizing accessions of biomaterials.

View full abstract

Chemical characterization of soil organic matter was examined by Curie-point pyrolysis-gas chromatography-mass spectrometry. 1) Except for drying and milling, no pre-treatment of the samples is required. 2) Pyrograms of each soil showed a lot of peaks. 3) The reproducibility of the pyrograms indicated fairly good results. 4) The products of heat decomposition in Ichige soil yielded more abundantly than the other soils. 5) The major peaks of the pyrolysis compound from soils were identified as toluene, pyridine, methyl furfural, acetic acid, furfural, acetonitrile, phenol and cresol.

View full abstract

Tomato plants (cv. TVR-2) grown by hydroponics were collected biweekly together with nutrient solutions for hydroponics, fractionated into leaf lamina, petiole, stem and fruit, and analyzed with regard to main nutrient elements in each fraction. The concentrations of K, P and Cl in nutrient solution, as well as those of K, P and N in vegetative organs, decreased with thickening and ripening of fruits, which went up to ca. 50% of the plant shoot in dry weight and required these elements as Mg, Ca and S to a lesser extent, and the concentrations of these elements in nutrient solution and in vegetative organs increased with the growth of the plant. The proportion of cations contained in the whole plant shoot kept virtually constant during the growth, regardless of a considerable change of cation composition in nutrient solution. In sharp contrast to cations, the proportion of anions in plant was significantly affected by the growth stage and by a change of anion composition in nutrient solution. Thus, the proportion of the nitrate ion rapidly decreased with the growth, accompanied by a simultaneous increase in the proportion of the sulfate ion. The leaf lamina and petiole were very different from each other in chemical composition, despite their close location in plant. This fact suggests that the leaves of tomato have to be divided into lamina and petiole prior to diagnostic analysis of the plant.

View full abstract

The effects of sulfide in blast furnace slag on growth of Red clover (Trifolium pratense L.) and Italian ryegrass (Lolium multiflorum LAM.) were studied with pot experiments growing in greenhouse for 49-51 days. Slag had been applied to humus-rich Andosol at 300 t/ha level for 8 years before. Phosphate was applied to the soil as the basal dressing at levels of 0, 10, 40, 160 mg P/100g dry soil. The results obtained were as follows : 1) Sulfide originated from slag was detected at 9.4 mg S/100g dry soil. Concentration of extractable silicate (mg SiO_2/100 g dry soil) with pH 4.0 sodium acetate solution was 216-278 in slag-treated soil and 83-102 in control. 2) The development of Red clover and Italian ryegrass root was poor on slag-treated soils. Application of phosphate ameliorated the damage of root development due to slag application. 3) Shoot growth of Red clover was lower on slag-treated soils than control at any phosphate level. In the case of Italian ryegrass, slag applied to soil promoted its growth at highest phosphate level and there was no significant difference at lower phosphate levels. Silicate content in Italian ryegrass shoots was more than double on slag-treated soils as compared with control. 4) Negative effects of slag on Red clover growth disappeared when the soils were treated with diluted hydrogen peroxide solution (1.5 mg H_2O_2/100g dry soil) before planting ; this may be attributed to oxidizing of sulfide in soils. There was no difference in Red clover growth in control soils treated and not treated with H_2O_2, though phosphate absorption was increased by H_2O_2 treatment. These results obtained here indicate that sulfide in blast furnace slag even under upland condition 8 years after applying, has a potential to inhibit crop growth and phosphorus uptake when it comes in contact with roots.

View full abstract

Tubers of yacon (Polymnia sonchifolia or P. edulis), a crop native to the Andean Highlands, contain a large amount of oligofructans. We investigated fluctuation of fructose, glucose, sucrose and oligofructan (GF_2-GF_9) contents during growth and storage by using an HPLC. The average degree of polymerization (DP) of these sugars in the tubers increased during growth. The DP reached to 4.3 at harvest, and decreased again during storage. Glucose, sucrose and GF_2 decreased, whereas the oligofructans larger than GF_4 increased during growth. At harvest, total oligofructan content reached to 67% of dry matter, and the ratio of GF_2-GF_5 accounted for about 70% in the total sugars. Inulin and starch contents in the tubers were only less than 0.23% and 0.04% of dry matter, respectively. The tubers were stored in 3 ways : a soil pit in field, at 5℃ and 25℃. After 2 weeks, total oligofructan content decreased 21% in the soil pit, 33% at 5℃ storage and 41% at 25℃ storage. Oligofructan contents decreased gradually and fructose, glucose and sucrose contents increased during each storage. To efficiently obtain oligofructans from yacon tubers, it will be necessary to prepare them from the tubers just after harvest. For eating yacon tubers, it will be suitable to store them for several weeks.

View full abstract

A rapid plant digestion method for analysis of minerals in plants by lithium metaborate fusion ICP-AES was studied. The procedure established is summarized as follows. Weigh 0.5 g of dried plant sample in platinum crucible, and put it into muffle furnace for ashing at 500℃ 30 min. Add 1 g of lithium metaborate and mix well with the ash. Fuse the mixture in muffle furnace at 900℃ for 10 min. Dissolve the melt in 40 ml of 1 M nitric acid at 60℃. Dilute 100 ml by water, and analyze P, K, Ca, Mg, Si, Fe, Mn, Zn, Cu and Al by ICP-AES. The total time of analysis was about 90 min for digestion and about 5 min for ICP-AES measurement. The accuracy of this method was confirmed by analysis of five reference standard materials (NIES No.1, 7, NBS SRM 1572, 1573, 1575). This method is available for rapid analysis of silicon in plants, and Fe, Mn or Al in silicon-rich plants such as rice.

View full abstract

The relationship between the ion composition and EC (electrical conductivity) or the hydrostatic pressure of soil solution was studied. The results obtained were as follows. 1) It was presumed that EC of soil solution was predominantly derived from the electric charge of inorganic ions. EC was calculated from the composition of inorganic ions by the following equation : k=Σa_iλ_i where k was calculated EC, a_i was activity of ion or ion-pair i and λ_i was the limiting molar electrical conductivity of ion or ion-pair i. As the result of comparison between calculated and measured EC obtained from 525 samples of Andosols, both values were in fair agreement. 2) Values of EC and hydrostatic pressure of each hypothetical model solution were calculated by the above equation. It was confirmed that the rate of EC and hydrostatic pressure increasing brought by increasing of solute concentration of SO_4^<2-> solution was lower compared to NO_3^- or Cl^- solution.

View full abstract