黒土に対する微量要素の効果について(農芸化学部門)

京都府下胡麻開拓地の黒土に対する微量要素施用効果について小麦を用いて圃場試験を行なつた。その結果, 生育調査においては微量要素区が標準区より草丈では若干劣る様であつたが, 穂長および分けつ数では勝れていた。収量調査においては明らかに微量要素の施用効果が認められ, 10a当りklを標準区100とした場合, 無肥料区84,銅区117,マンガン区110,銅+マンガン区103,FTE区111であつた。また収穫後の穀粒および藁稈について銅およびマンガンを, 跡地土壌については全銅, 置換態銅, 全マンガン, 置換態および還元態のマンガンを定量した。その結果, 微量要素施用区の吸収量は穀粒部分では差異が認められず, 藁稈部分で銅およびマンガン施用区はともに明らかにこれらの吸収量が高かつた。土壌については微量要素施用区はこれら要素が多く検出され, マンガン施用区では特に置換態と還元態のマンガン量が多かつた。A field experiment was carried out on the effect of minor elements on wheat. The field is located at GOMA Reclamation Land in KYOTO Prefectnre. The soil is classified as Kuroboku soil (black soil, ando soil). No distinct effect was found on the growth, however, clear effect was observed on the yield. The yield index of each plot which is calculated on the basis of yield of the plot without minor elements is : no fertilizer 84,copper 117,manganese 110,copper plus manganese 103,and FTE 111. FTE refers to fritted trace elements. Minor element analysis was conducted on the grains and straws, and also on the soils. The elements analyzed were copper and manganese on the crops, and total copper and manganese, exchangeable copper and manganese, and reducible manganese on the soils. No difference was found on the grain, however, a distinct difference was found on the straw. A large amount of exchangeable and reducible manganese were found on the soil of manganese plot

土壌および植生に及ぼす Nematocide の影響(農芸化学部門)

殺線虫剤としてVapam (natrium methyldithiocarbamate)およびNemafume (1,2-dibromethan)を用いて土壌処理を行ない, これが土壌および植生に与える影響について栽培および室内実験を行なつた。その結果, 生育および収量においては, 対照区よりVapam処理が有効であつたがジイナ数が多いため稔実歩合が悪く稔実重において変化がなかつた。土壌のEhの変化においてはVapam処理が他の区に比べて, 初期にEhの低下が見られ, 最低電位を示す時期が1週間早かつた。根のカチオン置換容量は僅かであるがVapam区およびNemafume区が対照区より大となつた。水田および畑状態におけるアンモニアおよび硝酸態窒素の消長については水田状態の場合, 各試験区ともアンモニア態窒素が増加し硝酸態窒素が減少するという消長経過を示したが, 量的にはVapam区が最もすぐれていた。畑状態の場合はNemafume区および対照区はアンモニア態窒素が減少し, 硝酸態窒素が増加する消長経過を示したにもかかわらず, Vapam区が他の2区と逆の消長を示し, かなりアンモニア態窒素の増加が認められた。従つて部分殺菌の効果としてはVapamがすぐれていることがわかつた。Effect of nematocides on some soil properties and rice growth was studied. The nematocides used were Vapam (Na-methyl dithiocarbamate) and Nemafume (ethylene dibromide). The results are summarized as follows : 1. The yield of rice grown on the soil treated with vapam was higher than the yield on untreated soil. However, no distinct effect was found on the weight of seed. 2. Cation exchange capacity of the root increased by the application of nematocides. 3. Oxidation reduction potential of the vapam treated soil showed lower value than the potential of the untreated soil. 4. Laboratory experiment was conducted on ammonification and nitrification in the soil. Soils were incubated under paddy field and upland field conditions. Determination of ammonium and nitrate nitrogen was run after 3,7,14 and 21 days the experiment started. The amount of both nitrogen was higher in the treated soil than in the untreated soil. The soil treated with vapam showed a degree of high amount of ammonium nitrogen compared to the untreated soil

土壌の物理的及び化学的性質に及ぼす土壌調整剤の影響(農芸化学部門)

無機質の埴質土壌に調整剤A-22及び石灰を添加して団粒形成量とその分布状態, 透水性, 置換容量及び燐酸吸収力について実験を行つた。調整剤は土壌に対して0.03%及び0.05%, 石灰はカチオン置換容量に相当する量を加えた。本実験の結果を要約すると次の如くである。(1)団粒形成量については調整剤及び石灰添加の効果が明らかに見られた。(2)透水性は調整剤添加によつて早くなるが, 0.05%区では0.03%区よりも遅く, 石灰の併用は多少阻害する様である。(3)置換容量及び燐酸吸収力については調整剤の添加量と共に増大した。A soil conditioner, A-22,was applied to an inorganic clayey soil. Lime was applied combined with the soil conditioner. The amount of lime was just equal to the cation exchange capacity of the soil, and the amounts of soil conditioners were 0.05 and 0.03 per cent of the soil weight. Experiment was carried out on the effect of the soil conditioner on aggregate formation, water permeability, cation exchange capacity and phosphorus adsorption. The results are summarized as follows : 1) Formation of soil aggregate was remarkably affected by the application of soil conditioner and lime. 2) Water permeability was increased by soil conditioner. The increase by 0.03 per cent application was larger than the increase by 0.05 per cent application. Slight decrease of permeability was observed by the addition of lime. 3) Cation exchange capacity and phosphorus absorption of the soil increased by the application of soil conditioner

京都府丹後地方および愛知県三河地方の森林土壌の鉱物学的研究(農芸化学部門)

京都府丹後地方の酸性褐色森林土地帯と愛知県三河地方の赤黄色土地帯に分布する種々母材を異にする土壌の鉱物学的研究を行ない。次の結果を得た。これらの2つの土壌生成作用に伴つて起こる粘土の風化生成過程には著しい相違は両者の間に認められず, 現気候条件下で安定と思われる風化最終産物はハロイサイト, ギブサイトであつた。しかし現在土壌中にみられる粘土鉱物は母材および土壌生成作用を受けた時間により差異があることを明らかにした。The mineralogical studies of the forest soils in Tango of Kyoto Prefecture and in Mikawa of Aichi Prefecture, which are developed on the various rocks under the climatic conditions of the formation of brown forest soil and red yellow soil, were performed. The petrographic methods were applied for the studies of sand fractions and the X-ray diffraction procedure, the differential thermal analysis and the other methods for sand and clay fractions. The results were summerized as follows. The sand fractions were containing the considerable amount of clay minerals in Tango soils, but the small amount in Mikawa soils except in the serpentine soil. The species of clay minerals in sand fractions were resemble to the ones in clay fractions. The various clay mineral species were detected in the clay fractions due to the variations of par ent material and the differences of soil age. But it was considered that there were no marked differences on the processes of clay formation occured during the forming processes of brown forest soil in Tango and red yellow soil in Mikawa, and the most stable weathering products were halloysite and gibbsite under present climatic conditions

京都市近郊の水田土壌の鉱物学的研究(農芸化学部門)

京都市近郊の水田土壌の鉱物学的研究を行ないその結果より, 土壌母材と鉱物組織との関係, 土壌生成作用と鉱物の風化過程との関係, 土壌の生産力と鉱物組成との関係について考察を加え, 次のような結果をえた。土壌の鉱物組成は母材との関係は認めうるが土壌型とは関係がなかった。すべての土壌がイライト, 非膨脹型14A鉱物およびハロイサイトを含み, 量的には母材によって変っていた。京都北部山間部の水田にはアロフェンやモンモリロナイトを含むものもある。非膨脹型14A鉱物は二八面体のバーミキュライトの層格子間にギブサイト様水酸化アルミニウム層をはさんだ鉱物であった。供試土壌では母材の不均一性のためまた水田化されて以来の経過年次が短かく明らかでないため, 土壌断面における鉱物組成の変化がわずかで土壌生成作用と鉱物の風化過程を明確には推察しえなかった。しかしはげしい風化を受けている土壌にあっては粘土鉱物の退化, 破壊が表層で起っていることを認めた。The mineralogical studies of paddy soils near Kyoto City were made and the relationships between the mineral weathering and soil forming processes and also those between the soil productivity and mineralogical compositions of soils are discussed. The results obtained indicate that the mineralogical compositions of soils are related to the parent materials and not to the soil types. All soils contain illite, non-expanding 14A mineral and halloysite, but the quantities vary according to the origns of parent materials. And the clay contain dominantly montmorillonite and allophane respectively in Soil A and B taken from the mountainous area in the northern part of Kyoto. Non-expanding 14A mineral may be dioctahedral vermiculite which sandwiches gibbsite layer between the layer lattices and chlorite. The mineral weathering processes in sample soils cannot be inferred from variations in mineralogical composition of profile samples, because of the considerable differences of parent materials even in a profile as well as the ambiguity of the elapsed years after the land reclamation to the paddy fields

γ線種子照射が水稲の生育と養分吸収に及ぼす影響(農芸化学部門)

水稲種子にγ線を照射した場合, 無照射種子との間に生育および養分吸収に差異が生じるのではないかと考えられるので栽培試験を行ない, 各生育時期別に三要素の吸収状態を調べた。その結果γ線照射種子は無照射種子に比べ, 生育は初期にはすぐれていたが後期において劣つた。しかし茎数においては生育各期を通じてすぐれていた。収量調査においては対照区より照射区の方が劣つた。生育各期における地上部の三要素含有率については, 窒素および加里では照射区が7月に最大の含有率を示したのに対し, 対照区では8月に最大含有率を示した。燐酸では, 照射区が生育の進むに従つて減少したのに対し, 対照区は8月に最大含有率を示しのち減少した。1株当りの各要素の吸収量の変化は照射区, 対照区ともに同様の傾向を示し, 9月に最大吸収量が認められ, 各時期とも照射区の方が対照区より吸収量が大であつた。根のカチオン置換容量については, 一定の傾向および差異が認められなかつた。Effect of γ-ray radiation on seed was studied on rice plant. Experiment was conducted on nutrient uptake and plant growth. The results are summarized as follows : 1. Distinct positive effect of γ-ray radiation was found on the growth at early stage However, no effect was observed on the yield. 2. The rice plant whose seed was radiated by γ-ray showed the highest percentage of nitrogen and potassium on July 24,However, the percentage of phosphorus decreased with growth. The rice from untreated seed showed the highest percentage of nitrogen, phosphorus and potassium on August 4. The amount of nitrogen, phosphorus and potassium absorbed by the treated and untreated rice showed the maximum value on September 5. The amount of these elements in the treated rice was higher than the amount of the untreated rice through all stages of growth. 3. No distinct difference and also no tendency of increase or decrease was found between the cation exchange capacities of roots of γ-ray radiated and check plants