While the available quantity of potash in soils is not insufficient for the crop production, this element, occasionally, does not display its desirable nutritive effect. It is doubtlessly considered that there should be some factors which reduce the availability of potash as plant food. The present paper deals with a study of the case in Tozan Vicinity, Rato-gun, Taihoku-shu. 1) The soil in Tozan Vicinity is alluvial clay-loam formed from clay-slate rocks. It shows slightly acid, as its pH value is 5.33 or the total acidity is 3.27. Quantity of K_2O, soluble in strong HCl, is 0.11% and easily soluble K_2O is more than 7 mg per 100 g soil. The latter has been determined in extracts obtained by distilled water, 1% citric acid solution, electro-dialysis and CaCl_2 solution. 2) According to the fertilizer experiment in the puddy field, vegetative growth and grain yield of rice noticeablly diminish in the plots with no potash, comparing with those in the other plots with this element. The soil requires 76.64kg of K_2O per hectare in order to produce the maximum yield of the grains when it is calculated from Pfeiffer's yield equation y = ax^2 + bx + c, applying the real yields of five crops and variable quantities of K_2O used as fertilizer. 3) The natural formation of soil layer in Tozan Vicinity is a little different from other places, as a thick gravel layer is accumulated under the soil. Through out the gravel layer underground water comes out, everywhere, in the puddy fields during the wet season. It separates very significant sediment of iron rust from the water on the soil surface. Since, the water contains a great deal of FeSO_4 which ultimately changes into red rust or Fe(OH)_3 obtaining oxygen from the atmosphere. 4) The soil contains 6.27% Fe_2O_3,soluble in strong HCl. Amongst, 0.6% is soluble by 1% citric acid solution and 0.02% is dialysable by means of the electricity. 5) Ashes of straw and grains of rice cropped from the different experiment plots have been analysed. The results show that the straw contains more amount of K_2O according to heavier application of that fertilizer, but it reversely contains less quantity of Fe_2O_3. It seemingly suggests there is a certain mutual relation or an antagonistic action between potash and iron in the plant body from the physiological view point. 6) Changes of the solubility of FeSO_4,on the other hand, have been tested, when an excess of FeSO_4 crystals has been added over saturation into every solution of different concentrations of K_2SO_4 and the mixtures have been kept at 30℃ shaking for a week. The test has been done by determinations of cations and anion in the mixed solutions. It is known by this way that thc solubility of FeSO_4 gradually decreases according to an increment of concentration of K_2SO_4,accompanying diminition of solubility of this salt to an extent. By mixing both sulphate solutions, it should be recognized the formation of a double salt, (K_2SO_4・FeSO_4・nH_2O, ) which will crystallizes and precipitates over saturation point. 7) The electro-conductivity of such solutions as above mentioned, at the same time, has been measured. The conductivity of mixed solutions accordingly increases to an increment of concentration of K_2SO_4,but it is smaller than sum of that of each solution. This indicates that dissociation of the salts in the solution diminishes by mixing, forming a new compound or the double salt in molecular equivalent. 8) From the result of various experiments, the authors may conclude that : (a) The available potash in the soil, as if it is not insufficient for plant growth is reduced its availability by mutual action with soluble iron which is excessively contained in the soil water. (b) The available potash forms a double salt with iron, under a certain condition, as both elements combine with the same kind of anion. (c) Formation of the double salt in the mixed solution diminishes

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This paper deals with the effect of lignin upon the decomposition of protein by determining NH_3-N and NO_3-N (and sometimes CO_2) liberated when lignin prapared from various plant materials, was added to protein in culture solution and in soil under both the dry and the paddy field conditions and the following results were obtained : 1) In the case of culture solution, when heated, the decomposition of protein was retarded by lignin within the first four weeks, but when unheated, only within the first two weeks. 2) There was no marked difference in the above depressive effect among lignins from various plant materials except that form Quercus acuta which acted most. 3) In the case of soil, it was determined that the depressive effect was not so remarkable as in the culture solution and that the retardation started when the ratio of lignin and protein was more than six to one. 4) It was also experimented that the effect of lignin was marked on nitrification and only a little on ammonification. The above fact may suggest that the depressive effect of lignin on protein decomposition is important in dry field and not so in paddy field condition.

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Was der Wert des Harnstoffstickstoffes als Stickstoffdunger betriflt, so zeigt sich, dass Harnstoffstickstoff im allgemeinen nach dem Ergebnisse vieler Dungungsversuche mit sowohl Ammoniak-als Nitratstickstoff etwa gleich verwertet wird. Das Nachteil des Harnstoffes als Kunstdunger liegt in seiner Hygroskopicitat. Als Harnstoffverbindungen mit weniger Hygroskopicitat als reines Harnstoff wurden Harnstoffnitrat und Harnstoffgips von den Verfassern hergestellt. Das Zweck dieser Versuche liegt darin, den Einfluss dieser Harnstoffstickstoffes auf das Wachstum der Reispflanze und auf die Qualitat der Ernteprodukte mit Ammoniakstickstoff, und zwar mit Schwefelsaurem Ammoniak zu vergleichen. Als Reispflanze wurde Taichu Nr. 65 benutzt. Der Boden war lehmtoniger. Die Versuche wurden mit den Gefassen, die jc 5 Kg. Boden enthalten, ausgefuhrt, Jedem Gefasse wurden als Grunddungung 0.3g P_2O_5 als Superphosphat und 0.3g K_2O als Kalisulphat zugegeben. Stickstoffmenge in verschiedener Formen fur jedes Gefass war 0.4g. Das Resultat dieser Versuche ist folgendes : 1) Das Wachstum der Reispflanzen ist beinah gleich bei allen Gefassen mit der Ausnahme der Gefassen ohne Stickstoffzusatz, bei denen das Wachstum immer etwas zuruckbleibt. 2) Schwefelsaures Ammoniak zeigte ausgezeichneten Einfluss auf die Ernte von Stroh und Blatt aber in bezug auf die Zahl und die Qualitat der Korner zeigte es ein schlechteres Resultat als das Harnstoffstickstoff. 3) Das Harnstoffstickstoff in drei Formen zeigte etwa so guten Einfluss wie Ammoniak betriffs der Ernte von Stroh und Blatt und es hat mehr Zahl und bessere Qualitat der Korner herbeigebracht. Im ganzen hat Harnstoffgips das beste Resultat unter allen Probedungern gezeigt.

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A study was made of the influence of dicyandiamid, guanidinphosphate, guanidinhy-drochloride, guanidinnitrate and guanylureaphosphate on the activities of the microbes. The reults obtained as follows : (1) In the neutral solution, dicyandiamid, guanidin and guanylurea are not decomposed by the sterilization. (2) Dicyandiamid, guanidin and guanylurea do not affect ammonification of urea, but do inhibit nitrification of ammoniumsulphate where the injurious effect of guanylurea is not so great as in the cases of dicyandiamid and guanidin. (3) Dicyandiamid and guanidin salts are toxic to Azotobacter chroococcum. (4) Aspergillus niger can not utilize dicyandiamid and guanidin salts as a source of carbon, but only as a source of nitrogen. (5) Aspergillus niger can utilize guanidinphosphate and guanylureaphosphate as a source of phosphorous. (6) Guanidinphosphate is more rapidly decomposed to ammonia and urea than guanidinhydrochloride by the action of water extract of Aspergillus niger which is developed on the culture media with respective guanidin salt, but dicyandiamid and guanylureaphosphate are not decomposed at all. (7) No ammonia is formed from guanylureaphosphate by the action of urease.

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Two sets of pot experiment were carried out, one in the glass-house, and the other out of it in the daytime, to know how the difference of these conditions effect the manurial value of N, P_2O_5 and K_2O of the soil. During the experineut the average temperature was measured higher, and the average humidity, lower in the glass-house thau out of it. The weights of the straws obtained were smaller from the pots in the glass-house than the corresponding pots out of it, but the weights of the grain were, in general, vice versa. No such differences were found in the manurial value of N of the soil as that of P_2O_5 and K_2O of the soil, which were shown remarkably more effective at the pots grown in the glass-house than out of it, showing that the effect of dressing P_2O_5 or K_2O will be greater when the pot experiments are carried out of the glass-house.

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The lupine(Lupinus luteus L.) was grown under the field condition as follows : 1.Seed inoculation plot. 2. Soil inoculation plot. 3.Uninoculation plot. and examined the effect of inoculation on the lupine as green manure, reference to its changes in composition toward the maturity. And the excellent result was obtained in the seed inoculation plot which was the best of all. The nitrogen and ash contents were much greater at the young stage of the growth than the matured but the organic matter was the opposite.

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The present paper is continued from the preceding one reported by one of the authors (1931) in another bulletin. From the development of the inhib ted or stimulated zone around the colony of actinomyces on agar plates seeded with the nodule bacteria, and the growth of streak cultures removed from mixed liquid cultures on crystal violet plates, it was thought, that A. roseus, A. viridochromogen, A. aureus and A. cellulosae were more or less harmful on some kinds of the species tested, while A. flavus remarkably inhibited the growth of them. None of these species seemed to grow beneficially it association with actinomyces. With regard to alfalfa bacteria, no harmful effects of A. flavus and A. roseus were found in the soil medium, hence the nodule formation on roots of young plants inoculated with highly diluted soil suspension was not retarded.

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