Ohtake Norikuni

Niigata University · Faculty of Agriculture

Concern that depletion of fertilizer feedstocks, which are a finite mineral resource, threatens agricultural sustainability has driven the exploration of sustainable methods of soil fertilization. Given that microalgae, which are unicellular photosynthetic organisms, can take up nutrients efficiently from water systems, their application in a biolo...

Deep placement of coated urea, lime nitrogen (Lime N), or urea with a nitrification inhibitor, 3,4-dimethylpyrazole phosphate (DMPP-U) did not inhibit N fixation activity, and it promoted soybean growth and seed yield. However, the effect of deep placement on the N budget including N leaching has not been evaluated. In this research, soybean plants...

Vanda is an economically important orchid that is widely produced in Thailand. Usually, growers apply large amounts of fertilizer throughout the plant, covering the leaves and roots to ensure good quality products. Nitrogen fertilizer, in terms of ammonium (NH4+) and nitrate (NO3−), is generally used as an N source. In addition, nitrogen organic fe...

Soybean plants require a large amount of nitrogen either from nitrogen fixation in nodules or nitrogen absorption from roots. It is known that nitrate, a major inorganic nitrogen compound in upland soils, represses nodule growth and nitrogen fixation. Rapid and reversible inhibition of nodule growth and nitrogen fixation activity was found in the h...

The waste sludge from food factories has rich nutrients and useful material for fertilizer or animal feed, but quick treatments and recycling of the waste sludge are difficult due to its higher water content. We have developed a rapid composting system to make sludge fertilizer using mix of waste sludge and shredded newspaper (Sludge Fertilizer Mad...

Soybean (Glycine max (L.) Merr.) plants form root nodules and fix atmospheric dinitrogen, while also utilizing the combined nitrogen absorbed from roots. In this study, nodulated soybean plants were supplied with 5 mM N nitrate, ammonium, or urea for 3 days, and the changes in metabolite concentrations in the xylem sap and each organ were analyzed....

Soy sauce cake, a waste product by a soy sauce production, contains a high concentration of protein, so it is a good material for animal feeds and fertilizers. However, soy sauce cake contains a high concentration of salt (NaCl), so the application of a high amount of soy sauce cake as a fertilizer may induce salt stress of the crops and salt accum...

It has been reported that supply of nitrate to culture solution rapidly and reversibly inhibits nodule growth and nitrogen fixation activity of soybean. In this study, the effects of ammonium, urea, or glutamine on nodule growth and nitrogen fixation activity are compared with that for nitrate. Soybean plants were cultivated with a nitrogen-free nu...

Photos of root systems with various N treatments for 1 week (Experiment 4). White square is 3 cm × 3 cm.

Dry weight of nodules (A) after 2 weeks of N treatments, and the increase in the volume of three selected nodules in the first and the second week (B) (Experiment 4). Averages and standard errors are shown (n = 3). Different letters above the column indicate significant differences at <0.05 by Tukey’s test.

Dry weight of each organs after 2 weeks of various N treatments (Experiment 4).

SPAD value of the second, third, and fourth trifoliolate leaves after 2 weeks of various N treatments (Experiment 4). Averages and standard errors are shown (n = 3). Different letters above the column indicate significant differences at <0.05 by Tukey’s test.

Percentage distribution of 13C among each tissue of soybean plants (Experiment 3).

Total leaf area per a plant after 2 weeks of various N treatments (Experiment 4). Averages and standard errors are shown (n = 3). Different letters above the column indicate significant differences at <0.05 by Tukey’s test. ∗Indicate significantly differences between control at <0.05 by Student’s T-test.

Dry weight of each tissue of soybean plants (Experiment 3).

Percentage distribution of 15N labeled source among each tissue of soybean plants (Experiment 3).

Relative concentration of free amino acids in each tissue of soybean plants treated with N compounds relative to control plants (Experiment 3).

13CO2 injection into a plastic bag covering the plant shoot (Experiment 3) (A). CO2 concentration was monitored by infrared CO2 analyzer (B).

Nodule number per single plant at 17 DAP supplied with various nitrogen compounds from 12 to 17 DAP (Experiment 1). Averages and standard errors are shown (n = 4). Different letters above the column indicate significant differences at <0.05 by Tukey’s test.

Photos of shoot organs with various N treatments for 2 week. White square is 3 cm × 3 cm (Experiment 4).

Nitrogen concentration of free amino acids in each tissue of soybean plants treated with N compounds for 3 days (Experiment 3).

The deep placement of urea fertilizer (DMU) containing 1% (W/W) of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) on soybean growth and seed yield was as effective as those of the coated urea (CU) and lime nitrogen (LN) in a field research. The average seed yields were high in LN (464 g·m ⁻² ) and DMU (461 g·m ⁻² ) and relatively...

Vanda is an important ornamental tropical orchid in Thailand and shows great potential in international markets. Since there has been limited research on flowering processes and regulations, flower production programs cannot be properly managed. To understand the genetic mechanisms in the Vanda flowering process, the ortholog of the FLOWERING LOCUS...

Leguminous plants form root nodules with rhizobia that fix atmospheric dinitrogen (N2) for the nitrogen (N) nutrient. Combined nitrogen sources, particular nitrate, severely repress nodule growth and nitrogen fixation activity in soybeans (Glycine max [L.] Merr.). A microarray-based transcriptome analysis and the metabolome analysis were carried ou...

Vanda is an aerial tropical orchid native to Thailand and nitrogen (N) fertilizer is mainly used to promote its growth and quality. However, little is known about the characteristics of N absorption and assimilation in Vanda. The objective of this study was to determine the appropriate source of N for Vanda cultivation. In this experiment, shoots a...

Soybean plants can fix atmospheric dinitrogen (N2) in root nodules by the association with soil bacteria rhizobia. Soybeans also absorb soil N from the roots, mainly in the form of nitrate in the upper fields. However, it has been known that nitrate strongly inhibits nodulation, nodule growth and nitrogen fixation activity of soybean nodules. Many...

Leguminous plants form root nodules with rhizobia that fix atmospheric dinitrogen (N₂) for the nitrogen (N) nutrient. Combined nitrogen sources, particular nitrate, severely repress nodule growth and nitrogen fixation activity in soybeans (Glycine max [L.] Merr.). A microarray-based transcriptome analysis and the metabolome analysis were carried ou...

Soybean is an important crop for human food and feed for livestock. World soybean production is increasing especially in North and South America. Soybean seeds contain a high percentage of protein about 35–40%, and they require a large amount of nitrogen compared with other crops. Soybean plants make root nodules with rhizobia, and rhizobia can fix...

An adequate supply of nitrogen (N) is important for Patumma growth and flower quality. This study aimed to compare the uptake and translocation of N by foliar and root application. Fertilization with ¹⁵ nitrate (NO3)-N via roots or leaves was carried out at four stages, at the 1st to 4th fully expanded leaf (FEL) stages, and the plants were sampled...

Anatomical characteristics of Curcuma alismatifolia Gagnep have been rarely studied, especially those of roots and leaves which are involved in nutrient uptake. Fertilization for production of C. alismatifolia is supplied both via roots and leaves. Therefore, this research aimed to study the anatomy of both organs by paraffin embedding and light mi...

Curcuma alismatifolia rhizomes are exported to world markets for ornamental use. Rhizome size and the number of storage roots affected shoot sprouting, plant growth, and inflorescence yield and quality, indicating an important role for storage food reserves such as the carbohydrates and proteins in these organs. An understanding of the proteins use...

The application of combined nitrogen, especially nitrate, to soybean plants is known to strongly inhibit nodule formation, growth and nitrogen fixation. In the present study, we measured the effects of supplying 5 mM nitrate on the growth of nodules, primary root, and lateral roots under light at 28 °C or dark at 18 °C conditions. Photographs of th...

Curcuma alismatifolia has become popular as an ornamental plant because of its colourful, long-lasting, and repeated growth of inflorescences.The effects of temperature on N and C assimilation and transport during the initial flowering stage were investigated using 15N and 13C. Treatments at 15ºC, 25ºC, or 35ºC had no significant effect on total 15...

The quantitative analysis of the initial transport of fixed isotope 15-nitrogen (15N) in intact nodulated soybean plants (Glycine max [L.] Merr. cv. Williams) was investigated at the vegetative stage (36 days after planting, DAP) and pod-filling stage (91 DAP) by the 15N pulse-chase experiment. The nodulated roots were exposed to N2 gas labeled wit...

Tulip (Tulipa gesneriana, cultivar Oxford) bulbs were planted in October and grown in culture solution in a glasshouse under natural conditions. One group was cultivated in a solution containing nitrogen (N) (+N treatment: nitrate-N (N) 12.0, ammonium-N (−N) 3.0 mg L). Another group was cultivated in a nitrogen-free solution (−N treatment). In the...

The effects of different temperatures (30/24 o C and 30/18 o C day/night temperatures) and N sources; nitrate (NO 3 -), ammonium (NH 4 +), mixed-N source (50 NO 3 -:50 NH 4 +) in the nutrient solution on growth and N assimilation of Curcuma alismatifolia was studied in a soil-less culture medium. Plant grew taller when grown under the 30/24ºC treat...

Curcuma alismatifolia Gagnep. rhizomes were planted on 15 May 2007. At 10 weeks after planting, at the termination of the new leaf formation stage, the plants were supplied with 15 N-labeled culture solution (3.81 mM NH 4 + + 8.96 mM NO 3 -: 10.6 atom% 15 N) twice at 3 and 1 days before 13 CO 2 feeding. Then 13 C-labeled 13 CO 2 (99 atom% 13 C) was...

We determined the critical nitrogen (N) level in field-grown Curcuma alismatifolia Gagnep. by applying N at a rate of 3.75, 7.5, 15, 30, and 60 g N plant –1 as urea. Plant growth and N critical levels were determined 105 d after planting (flowering stage). To establish critical N levels in plant tissue, the relationship between rhizome yield and th...

The purpose of this work was to investigate the change of MIR characteristics of rice in storage using FT-IR/ATR spectroscopy. Firstly, grain number in the FT-IR/ATR measurement was examined to obtain the average spectral information of rice grain. In the experiment, measurement of 300 grains was performed and its spectrums were analyzed. As a resu...

Soybean seeds contain a large amount of protein (about 35%), and there is a significant correlation between the total amount of N accumulated in soybean plants and seed yield. Soybean utilizes N from several sources, including mineralized soil organic matter, symbiotically fixed N, and N from fertilizer when applied. Soybean plants fix a large amou...

Off-season (OS) cropping of Curcuma alismatifolia Gagnep. in Thailand results in a decline in plant growth and flowers quality compared to regular sea-son (RS) cropping. This may be due to the distinct cli-matic conditions in OS such as short day length, low temperature, water stress etc. which induce changes in some endogenous hormones and alter p...

Curcuma or Siam tulip (Curcuma alismatifolia Gagnep.) is an ornamental flowering plant with two underground storage organs, rhizomes and storage roots. Characteristics of N and C assimilation and transport in curcuma were investigated. The plants were treated with (15)NH(4) (+) + (15)NO(3) (-) and (13)CO(2) at 10, 13 or 21 weeks after planting. Pla...

The effects of low night temperature (LNT) and short day length (SDL) on the plant growth, phytohormone concentration and nutrient status in leaves, rhizomes and storage roots of Curcuma alismatifolia Gagnep. at the flowering stage were studied. In the first experiment, plants were grown under controlled conditions of 30 /24 ° C (day/night temperat...

The fate of nitrogen fixed in soybean nodules was investigated by tracer experiments with 15 N 2 gas. The results indicated that the major part of fixed ammonia in bacteroid (a symbiotic state of rhizobia) is rapidly excreted to the cytosol of infected cells in nodules, then the ammonia is assimilated into amino acids via glutamine synthetase/gluta...