Heavy nitrogen isotope of 5.67 atom % N^<15> excess in the form of ammoium sulfate was added along with some soluble starch to the soil, previously air dried and not dried respectively. The soils were incubated three weeks at30℃ under waterlogged condition followed by the analysis of NH_4-N, humic-N, non-humic-N (Hopson-Page) contents. As revealed by massspectrum analysis of N^<15> the nitrogen fractions in the humic and non-humic N originated from the inorganic N^<15> were considerably high, the effect of air drying resulting in the less transformation in the organic nitrogen as compared with non-drying. The analitical results were discussed in comparison to the ordinary method of substraction (plot in question - check plot), the latter undoubtedly gave unreliable results.

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Rice plant were supplied 14 days before heading with (N^<15>H_4)_2SO_4 containing 5.67 atom per cent excess. At the periods of heading and full mature, plants were heavested, separated into several parts, and analyzed for their nitrogen content and concentration of N^<15>. The high level of N^<15> in ears, culms, and boot leaves at heading as contrasted with other parts, and comparison of N^<15> concentration between two periods suggested that the principal parts of N^<15> were utilized as the raw materials for the growth of those organs which were at their highest activities. N^<15> Which translocated in the leaves at heading were regard as storage nitrogen, because they were gradually removed to other parts. In the roots N^<15> were utilized both for the formation of new rooots and storage nitrogen.

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By the potentiometric titration using the vaccumtube U_y-111. the micro determination of foric acid is done rapidly with sufficient accuracy. Carbon dioxid and hyda chloric acid as the impurity matter have to be removed.

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It is expected from the climatic condition that Red and Yellow Soils may be found in most places of the south-western part of Japan Where volcanic ashes have not deposited. In this paper the morphological and chemical characteristics of the Red Soil occurring in Northern Kyushu Which belongs to the warm and humid temperate region, are described. The profile characteristics of the Red Soil formed over the highly unsaturated alumino-silicic shale of the Tertiary Period are shown in Table 1. In considering the fact that the A horizon does not show any evidence of bleaching, it is clear that the Red Soil is not identical With the podzolic Red Earth (by THORP). Although SWANSON has designated the Red Soil as the Reddish-Brown Lateritic Soil which is characterized by friability in consistency, the crumbs of the Red Soil in Kyushu, however, do not possess such friability when dry and, consequently, the soil cannot be regarded as the Reddish-Brown Lateritic Soil. In our opinion the soil rather resembles the Red Earth (non-podzolic) of Central and South China (by THORP) in many respects. The mechanical and chemical characteristics of the soil are given in Table 2. The table shows heavy clayey textures throughout the profile and, especially, an accumulation of clay in the B horizon. It is probable that some of the clay in the B horizon has been mechanically washed down from the present A horizon and, perhaps, from the past upper horizons which had been removed by erosion. The soil is characterized by the low content in organic matter, the strong acidity, the high degree of leaching of alkalies and alkaline earths, and very low base status. In particular, it is interesting to note that the acidity, as measured by pH value, increases with the depth. Such a increase in acidity in the red soils of the tropics has been noticed by DOYNE and other English soil scientists, and furthermore, TAMACHI has also recognized such feature in the podzolic soils derived from shales of the Tertiary Period in Northern Japan. Such feature of the Red Soil in Kyushu may be explained by the fact that the parent materials possess the extremely low base status. Besides, it must be remarkable that the exchangeable acidities (y_1), as have already been noticed by KAWAMURA and AOMINE, are stronger than the hydrolytic ones (y_1) in the lower horizons and the parent materials. The chemical compositions of the colloidal fraction show a slight accumulation of iron in the B_1 horizon. Silica-alumina ratios of the colloids are about 2.5 which would place them in the group of siallitic red earths according to HARRASSOWITZ's classification, and these ratios resemble those of the Red Earths in China. Since the exchange reactions (pH in water minus pH in 0.01n sodium sulphate solution) of air-dried soil materials give approximately an exchangeable neutrality throughout the profile, it may be considered that the Red Soil in Kyushu, as MATTSON has stated, is not cationically eluviated, but it belongs to the anionically eluviated group occupying an intermediate position between brown forest soils and lateritic (allitic) soils. The Red Soil of this type has its narrow distribution in Japan.

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(1) The length of time of the aqua regia digestion are giving showing that have an effect on the results for the insoluble material in phosphate rock. (2) The silica was determined in a number of samples of phosphate rocks by the Berzelius and ordinary alkali fusion methods. The results show that, owing to the presence of fluorine in phosphate rock the percentage of silica obtained by method of ordinary rock analysis, are 0.02〜2.22 percent lower than the percentages obtained by the Berzelius method. (3) The Berzelius procedure is shown to be applicable to the determination of silica in phosphate rock. (4) The silica contents was determined on the phosphate rocks from continental or Island origins by the Berzelius method. The average contents from Florida was 10.43% the Idaho, 6.56% : the Algeria 1.60% : the Egypt, 5.29% : the Morocco, 1.60 : the Angaur, 0.46% : the Christmas, 0.27% : the Makatea, 0.33% : the Ocean, 0.65% : the Raokai, 5.81% : the Paracel, 0.28%. (5) The amounts of hydrochloric acid, sodium carbonate, sulfuric acid soluble silica, and free silica as quartz was determined on the few samples. Chemical Research Institute, Taki Fertilizer manufacturing o., Befu

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The maturing process of newly reclaimed soils is said to be the process in which forest soil converts to stepp soil, and especially on diluvial volcanic ash soil which occupies the large area among the land to be reclaimed in our country, that is also the process of diminishing the allitic properties. Formally K.KOBO proved that rotted products diminish and the form of humus stabilizes with the increase of the exchangeable calcium of soil, in the maturing process of uncultivated soils after reclamation, and assumed that those atabilization of humus was to contribute to form humosilicate complexes. In these researches of carbon contents, base exchange capacities, and isoelectric points in comparing uncultivated soils with the adojoining long cultivated soils, we have come to acknowledge the following facts : 1) In the maturing process of newly reclaimed soils, humus contents tend to decrease, but no seeming changes are found in the base exchange capacity. 2) Humus which decreases after reclamation, namely rotted products, has a small base exchange capacity, and the diminution of the base exchange capacity of soil as a result of decrease of humus is compensated by the increase of the base exchange capacity of clay itself, which is brought about by the formation of humosilicate complexes after the stabilization of humus. 3) When unculticated soils, poor in exchangeable calcium, were reclaimed and cultivated for several years, isoelectric points of its surface soil together with subsoil are lowered with the increase of the exchangeable calcium. The above facts may verify the formation of humosilcate complexes in the maturing process of newly reclaimed soils.

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The respiration of the root-nodules of leguminous plants, detouched from roots, was studied by Warburg's mannometric method. The rate of respiration decreased in the generative stage of growth. The rate of respiration (Qo_2) of nodules and roots was not markedly different, though the respiration quotient of the former was in the average 0.89,and that of the latter 1.06 as for the soybean plant.

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1. The paddy soil in plot dressed repeatedly with phosphoric fertilizer shows higher content of humus than the soil undressed with phosphoric fertlizer. The results shown in table 8 show the fact that repeated dressing of phosphoric fertilizer in duces the accumulation of soil humus which is supposed to be due to the formation of humus from Lemnaceous weed and algae that tend to propagate by the dressing of phosphoric fertilizer, and also to the increase of plant debris as stubbles and roots as the plant grows vigorously by the dressing. 2. More amount of easily-decomposing humus exists in soil dressed with phosphoric fertilizer than in soil undressed. In other words, there are differences in the forms of humus or nitrogenic substance of dressed and undressed soils. As shown in table 2,some differences can be observed in carbon ratio between dressed and undressed soils which are clear from the comparison of the amount of carbon and nitrogen and also of the carbon ratio of dressed and undressed soils. In addition, it is presumpted that more amount of easily decomposing humus and available nitrogen exists in soil dressed with phosphoric fertilizer than in undressed soil as there is difference in the effect of drying and heating of dressed and undressed soils as shown in table 9. To verify this presumption, examination was carried out on the forms of nitrogen, the results of which are summarized in table 10,12,17 which shows the effect of drying and heating of soils and also in table 22. From these results the form of nitrogen differs each other in dressed and undressed soils in the following four points. (a) Amount of 2%-HCl soluble nitrogen. More amount of 2%-HCl soluble nitrogen exists decidedly in dressed than in undressed soil. (b) Amount of 2%-HCl soluble nitrogen formed by heating treatment up to 150℃. The formation of 2%-HCl soluble nitrogen by the heating treatment is decidedly bigger in dressed than in undressed soil. (c) Amount of insoluble nitrogen reduced by the heating treatment up to 150℃. The reduction of unsoluble nitrogen by the heating treatment is clearly more in dressed soil than in undressed. In other words, the dressed soil contains more amount of easily decomposing nitrogen. (d) Amount of 2%-HCl soluble nitrogen formed by the heating treatment up to 250℃. Alittle more nitrogen of this form exists in dressed soil. The above-mentioned differences are pointed out from the comparison of absolute amount of respective form, which are considered not to be erroneous as evidenced by the ratio of respective form to total nitrogen as shown in table 1,7 and in 20. 3. Therefore paddy soil reratedly dressed with phosphoric fertilizer shows higher productivity of nitrogenic orgin than undressed soil.

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