Nutrient and bulk density characteristics of soil profiles in six land use systems along topo-sequences in inland valley watersheds of Ashanti region,Ghana

The bulk density and nutrient distribution in soil profiles as affected by various land use systems were studied. Mean bulk densities of the various soil profiles, 0-20, 20-40, and 4060 cm in the selected five land use systems along the upland / lowland topo-sequences were, 1.26, 1.73, and 1.44 Mg m^-3 for the primary forest (PF) plot in the upland area, 1.13, 1.51, and 1.50 Mg m^-3 for the cacao farm (CP) plot, 1.16, 1.63, and 1.26 Mg m^-3 for the mixed cropping (MC) plot, 1.39, 1.61, and 1.50 Mg m-a for the fallow (Fallow) plot, all three land use systems being in the upland / fringe areas, and 1.46, 1.72, and 1.60 Mg m^-3 for the lowland traditional rice farming (TR) plot, respectively. The very high bulk density of the second layer, especially in the PF plot, may be related to the hardening of the iron / quartz stone layer due to prolonged dry conditions, which may affect plant growth and hydrological cycles in the benchmark inland valley watersheds. The TC contents of the topsoil samples were 43, 32, 24, 26, 18, and 15 g kgm^-1 for the PF, CP, Fallow, MC, TR, and sawah (Sawah) plots, respectively. The C / N ratios of the topsoil samples were 10, 10, 9.8, 9.1, 8.8, and 8.8 for the CP, Fallow, MC, Sawah, TR, and PF plots, respectively, displaying a higher natural fertility, especially for the N supply in the PF plot in the upland area. The available phosphorus levels were low even for the topsoil samples, 1.8 to 3.4 mg kg^-1 for the upland soils while the lowland TR and Sawah plots recorded values of 4.4 and 4.9 mg kg^-1, respectively. The contents of exchangeable K, 0.1-0.4 cmole kg^-1, of the topsoil samples were in the range of those of normal inland valley soils in West Africa. In contrast to the content of available P, although the MC plot showed a depletion, the PF, Fallow, and CP plots showed a replenishment of available K through biological nutrient cycling. The levels of exchangeable Ca and Mg as well as eCEC, were also relatively high compared to those of mean inland valley soils in West Africa. The major component of eCEC was Ex. Ca. The levels of Ex. Ca in the topsoil samples were 11.1, 9.1, 7.8, 4.7, 5.1, and 3.9 cmol_c kg^-1 for the PF, CP, Fallow, MC, TR, and Sawah plots, respectively. The distinctive feature of Ex. Mg was its large distribution in the upper soil profiles in the CP plot, indicating that in the cacao farms, Ex. Mg was enriched, probably due to the high level of Mg in the leaf litter. The lowland soils, normally, should have been enriched in exchangeable bases such as Ca, K, and Mg, leading to a higher eCEC value and higher general fertility through the process of geological fertilization, Le., nutrient flows from upland to lowland areas, as in the case of lowland sawah in monsoon Asia. At the benchmark sites, however, the effects of the geological fertilization process were not evident. This is one of the most important characteristics of West African inland valley watersheds.     

Varietal difference in radiocesium uptake and transfer from radiocesium deposited soils in the genus Amaranthus

Abstract

Within Amaranthaceae, 33 different varieties, including local varieties from Japan, were grown in 2012 in a field in the town of Iino in the Fukushima prefecture, which is located approximately 51 km north of Tokyo Electric Power Company, Fukushima Daiichi Nuclear Power Plant (FDNPP). The contamination level of the soil was 2770 ± 140 Bq kg^?1 dry weight (¹³⁴Cesium (Cs) + ¹³⁷Cs, average ± SE), and the field was also cultivated in 2011. There was a significant varietal difference in the dry weight production, radiocesium accumulation and transfer factor (TF) of radiocesium from the soil to the plant. The ratio of the lowest TF to the highest TF was approximately 3. Because the ratio of ¹³⁷Cs to ¹³³Cs was significantly positive, radiocesium seems to be absorbed in a manner similar to that of ¹³³Cs. It is suggested that the varietal difference in the behavior of radiocesium uptake mainly depends on its genetic background rather than on environmental factors.     

Protozoan predation of Escherichia coli in hydroponic media of leafy vegetables

Multiple outbreaks of food poisoning associated with fresh vegetable consumptions have occurred in many countries. Numerous reports have described human pathogenic bacteria, such as Escherichia coli O157:H7 and Salmonella spp., that can internalize into fresh vegetables via root or leaf surfaces. While attempting to obtain the threshold concentration of internalization of E. coli inoculated into hydroponic medium during vegetable cultivation, we observed a rapid decrease in E. coli numbers. In the present study, we determined that the rapid decline in E. coli was not due to a physiological change into a viable but non-culturable (VNC) state. The population crash was instead caused by true bacterial death, as the rapid descent was also confirmed by micro-colony fluorescence in situ hybridization, a culture-independent method that can detect VNC cells. We next monitored the number of E. coli inoculated into intact or filter-sterilized hydroponic medium after cultivation of various types of plants. We found that the number of E. coli in intact hydroponic medium decreased markedly, whereas the level in filter-sterilized hydroponic medium was completely unchanged. This result suggests that biotic factors were present that could be eliminated by filtering. Robust predation of E. coli by protozoa (ciliates and flagellates) was observed using fluorescently labeled bacteria incorporated into the hydroponic medium. Finally, morphological identification of flagellates by scanning electron microscopy revealed the presence of a species of Stramenopiles. These findings suggest the importance of protozoa as bacterial feeders in hydroponic systems and hence the use of these organisms as potential control agents of human pathogenic bacteria.     

Molecular complex of lignosulfonic acid/poly(vinyl pyridine) via ionic interaction: characterization of chemical composition and application to material surface modifications

Poly ion complexes of anionic lignosulfonic acid (LSA) with cationic poly(2-vinyl pyridine) or poly(4-vinyl pyridine) were prepared by mixing the polymer solutions in dimethyl sulfoxide or dilute hydrochloric acid. The complexes were formed as soon as the polymer solutions were mixed. Fourier transform infrared (FTIR) measurements for the complexes revealed the presence of strong ionic interactions between sulfonate anions of LSA and pyridinium cations of the vinyl pyridine (VPy) polymers. The strong interaction was supported by detection of a glass transition temperature (T _g) much higher than pristine T _g values of VPy polymers in differential scanning calorimetry. By using the ionic complexation, a coating of LSA onto VPy polymer films was undertaken to modify their original surface property. Formation of a thin complex film was confirmed by observation of absorption bands that are characteristic of the pyridinium cation in reflection FTIR spectra measurements, and by visualization of the attached LSA component in atomic force microscopy. This treatment resulted in the surface of the VPy polymer films becoming hydrophobic. An adhesion test was also conducted by pasting two veneered woods with the polymer complex, followed by shear-tearing them off. The adhesive strength of the complex was estimated to be 1.1 MPa. Part of this report was presented at the 55th (Kyoto, March 2005) and 56th (Akita, August 2006) Annual Meetings of the Japan Wood Research Society     

Influence of neutral inorganic chlorides on primary and secondary char formation from cellulose

The influence of various alkali and alkaline earth metal chlorides (LiCl, NaCl, KCl, MgCl₂, and CaCl₂) on primary and secondary char formation from cellulose was studied at 400°C. Secondary char was formed through carbonization of the volatile products. All chlorides increased the primary char yield while decreasing the secondary char formation, and this situation was promoted in the order of alkaline earth Mg, Ca, alkali Li > alkali Na, K. Levoglucosan yield also decreased along with the secondary char yield. These results indicate that the reduced formation of volatile levoglucosan was related to the decreasing yield of secondary char. A model experiment at 250°C revealed that these chlorides, especially the two alkaline earth metals, had catalytic action on the polymerization of levoglucosan, which serves to reduce the formation of volatile levoglucosan.     

At5g54160 gene encodes <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> 5-hydroxyconiferaldehyde <Emphasis Type="Italic">O</Emphasis>-methyltransferase

The function of an Arabidopsis thaliana gene, At5g54160 annotated as a caffeic acid O-methyltransferase CAOMT gene was characterized. The recombinant enzyme of this gene (AtOMT1) catalyzed the O-methylation of phenylpropanoid and flavonoid substrates. The specificity constants (k _cat/K _m) for 5-hydroxyconiferaldehyde (5-HCAld) and quercetin were both 0.11 μM⁻¹·min⁻¹. On the other hand, lignins of At5g54160-knockout Arabidopsis mutants lacked syringyl units. In addition, we showed that the gene silencing also resulted in significant accumulation of caffeyl alcohol (CaAlc). These results strongly suggested that At5g54160 gene is involved in syringyl lignin synthesis for the methylation of both 5-hydroxyconiferaldehyde and 3,4-dihydroxyphenyl compound(s). Part of this work was presented at the Annual Meeting of Japan Society for Bioscience, Biotechnology, and Agrochemistry, March 24–27, 2007     

Suppurative meningoencephalitis and perineuritis caused by Streptococcus gallolyticus in a Japanese Black calf

A 179-day-old calf, which was weak and stunted, showed neurological signs and was euthanized. Postmortem examination revealed extensive and severe cloudy area in the meninges, and pleural pneumonia. Gram-positive cocci were isolated from systemic organs. Biochemical and 16S rRNA gene sequence analyses identified the isolate as Streptococcus gallolyticus, and its subspecies was suggested to be gallolyticus (SGG). The isolate was classified as a novel sequence type (ST115) by the multilocus sequence typing scheme for SGG and showed susceptibility to penicillin, ampicillin, amoxicillin, florfenicol, sulfamethoxazole-trimethoprim, and chloramphenicol. Histopathologically, suppurative meningoencephalitis and perineuritis were detected. As SGG has been isolated solely from a cow with mastitis in Japan, this is the first SGG infection in a calf with suppurative meningoencephalitis and perineuritis in this country.     

Development and evaluation of pyramiding lines carrying early or late heading QTLs in the indica rice cultivar ‘IR64’

The heading date is an important trait for determining regional and climatic adaptability in rice. To expand the adaptability of the indica rice cultivar ‘IR64’, we pyramided multiple early or late heading quantitative trait locus (QTLs) in the ‘IR64’ genetic background by crossing previously developed near-isogenic lines (NILs) with a single QTL for early or late heading. The effects of pyramiding QTLs were observed in three different climatic zones of the Philippines, Madagascar, and Japan. The early heading pyramiding lines (PYLs) headed 6.2 to 12.8 days earlier than ‘IR64’ while the late heading PYLs headed 18.8 to 27.1 days later than ‘IR64’. The PYLs tended to produce low grain yield compared to ‘IR64’. The low yield was not improved by combining SPIKE, which is a QTL that increases the number of spikelets per panicle. Conversely, ‘IR64-PYL(7+10)’ carrying Hd5 and Hd1 headed earlier, produced more tillers, and more panicles per m² than ‘IR64’, and mitigated the yield decrease in early heading. These results suggest that the effects of pyramided QTLs on heading date were consistent across various environments and PYLs could be used to enhance the adaptation of ‘IR64’ in other rice growing environments.