Incorporation of 15N into various nitrogenous compounds in intact soybean nodules after exposure to 15N2 gas

The intact nodules attached to the upper part of soybean roots were exposed to ¹⁵N₂ and the incorporation of ¹⁵N into various soluble nitrogen constituents was investigated. Results indicated that ammonia, a primary product of N₂ fixation, was located in more than two compartments. Ammonia reduced from N₂ gas seemed to be incorporated firstly into glutamine especially amido-group nitrogen. Newly fixed nitrogen was secondly incorporated into glutamic acid and alanine in this sequence. These results suggested that fixed ammonia was assimilated by glutamine synthetase/glutamate synthase pathway. Turn-over rate of allantoin plus allantoic acid and serine was relatively high, although apparently these compounds were not primary products of newly fixed ammonia. ¹⁵N content of allantoin was always higher than that of allantoic acid. ¹⁵N incorporation to aspartic acid and asparagine was relatively slow, especially in early period. In bacteroid fraction there is much amount of ammonia comparing with other compounds, while allantoin and asparagine were presented exclusively in cytosol. ¹⁵N was incorporated into nitrate within a few minutes especially in bacteroids.     

The cumulative methane production from dairy cattle slurry can be explained by its volatile solid,temperature and length of storage

In order to refine the national estimate of methane emission from stored cattle slurry, it is important to comprehend the basic characteristics of methane production. Two dairy cattle slurries were obtained from livestock farms located in Hokkaido (a northern island) and Kyushu (a southern island). The slurries were diluted with water into three levels: undiluted, three times diluted, and 10 times diluted. Three hundred mL of the slurries were put into a bottle with a headspace volume of 2.0 L, which was filled with nitrogen gas and then sealed by butyl rubber. Four levels of temperature were used for incubation: 35, 25, 15 and 5 °C. The time course of the cumulative methane production per volatile solid (VS) was satisfactorily expressed by an asymptotic regression model. The effect of dilution on the methane production per VS was not distinctive, but that of temperature was of primary importance. In particular, higher temperature yields a higher potential production and a shorter time when the cumulative production reaches half of the potential production. The inclusive and simple models obtained in this study indicate that the cumulative methane production from stored cattle slurry can be explained by VS, temperature and length of storage.     

Heinz body hemolytic anemia with eccentrocytosis from ingestion of Chinese chive (Allium tuberosum) and garlic (Allium sativum) in a dog

A 4-year-old, intact male miniature schnauzer was presented with anorexia. The dog had ingested some Chinese steamed dumplings 2 days before, which contained Chinese chive (Allium tuberosum) and garlic (Allium sativum). Hematological examinations revealed severe Heinz body hemolytic anemia with eccentrocytosis and an increased concentration of methemoglobin, which was thought to result from oxidative damage to erythrocytes by constituents in these Allium plants. In this case, eccentrocytosis was a hallmark finding and could be detected easily, suggesting that this hematological abnormality is useful in diagnosing Allium plant-induced hemolysis.     

Deficiency of N,P, K,Ca, Mg,or Fe Mineral Nutrients in Narcissus cv. “Garden Giant”

Narcissus cv. “Garden Giant” bulbs were grown in N, P, K, Ca, Mg, or Fe-deficient solutions and compared with bulbs grown in the control solution containing all these nutrients. Plants were sampled at 4 stages: (I) at planting, (II) at sprouting, (III) after flower senescence and/or after visible deficiency symptoms developed, and (IV) at lifting. Observation of visible deficiency symptoms showed that leaves of narcissus displayed chlorosis in the —N, —Mg, and —Fe treatments, while roots were most susceptible to Ca-deficient conditions. Root tips in the —Ca treatment showed brown in followed by root rot. In the —N treatment, shoot growth was markedly retarded and leaves were small and yellow. On the other hand, visible deficiency symptoms were not evident in the —P treatment except for early senescence. K deficiency symptoms were also not evident. Narcissus flowers were not affected by the mineral deficiencies and mineral contents in full-bloom flowers were not different between samples.

In the control plants, there was a large accumulation of N in the roots at sprouting and the content decreased thereafter. Large amounts of K accumulated in roots more than in any other organs. On the other hand the Ca content was high in the tunic and Ca in the scales was hardly mobilized thoughout the growth period. A large proportion of each element eventually accumulated in new inner scales whereas only a small fraction in the old outer scales. The -N, -Ca, and -Mg treatments severely depressed dry matter accumulation, unlike the -P, -K, and -Fe treatments. The -N treatment did not affect the concentration of other minerals, but the -P treatment tended to decrease N, K, Ca, and Mg concentrations. On the other hand, the -K treatment increased Ca and Mg concentrations. -Ca caused an increase in Mg concentration and -Mg raised Ca concentration. These results may be due to compensation effects of cation absorption for the maintenance of the cation/anion balance.     

Improvement of application method of liquid fertilizer with irrigation water for uniform topdressing and change in nitrogen concentration of flooded water after application

(pp. 811–816)
The application method of liquid fertilizer with irrigation water was tested in large scale paddy fields using a newly developed fertilizer supplier which can make a supplying rate of liquid fertilizer constant. Uniformity of fertilization, change in the nitrogen concentration of flooded water and absorption of applied nitrogen by paddy rice were examined. High uniformity of fertilization was achieved with this method as compared with a conventional broadcast application of granular fertilizer, or an inflow fertilization of granule-like fertilizer with irrigation water.
When urea was applied as liquid fertilizer, the fertilizer-N disappeared quickly from ponding water under shallow conditions of ponding water depth. In the case of the same depth of ponding water, the rate of reduction was large under conditions of large permeability of water.
The nitrogen utilization rates of urea and ammonium sulfate labeled with ¹⁵N were not related to the depth of ponding water at the time of fertilization. When ammonium sulfate was supplied the nitrogen utilization rate was around 50% regardless of fertilization conditions however, the urea-N utilization rate fell to 40% or less at a permeability of ponding water of 0.8 cm day⁻¹ or less, while it increased to 50% equivalent to ammonium sulfate, at 0.8 cm day⁻¹ or more permeability.     

Properties of Microbial Biomass in Acid Soils and Their Turnover

The soil microbial biomass is important such as pool of plant nutrients and is also driving force of the cycling of C, N, P and S in soil. However, the microbial biomass in acid soil has not been fully investigated due to the limitation of methods, i.e. chloroform-fumigation incubation or substrate-induced respiration because of decreased basal mineralization in chloroform-fumigated soil under acid conditions. This paper reviews improvement and application of these methods and vertical distribution of microbial biomass in two kinds of acid soils; namely, Andisols as dominant upland soils in Japan and tropical peat soils as potentially important lowland soils for agriculture, and also discuss on C and N turnover of microbial biomass in Andisols. Microbial succession in acid soil has also not been investigated so much, but, some studies in another important acid soil, i.e. acid sulfate soil, were also reviewed briefly.