Changes of soil organic carbon and its fractions in relation to soil physical properties in a long-term fertilized paddy

Soil organic carbon (SOC) has an important role in improving soil quality and sustainable production. A long-term fertilization study was conducted to investigate changes in SOC and its relation to soil physical properties in a rice paddy soil. The paddy soils analyzed were subjected to different fertilization practices: continuous application of inorganic fertilizers (NPK, N–P–K = 120–34.9–66.7 kg ha⁻¹ yr⁻¹ during 1967–1972 and 150–43.7–83.3 kg ha⁻¹ yr⁻¹ from 1973 to 2007), straw based compost (Compost, 10 Mg ha⁻¹ yr⁻¹), a combination of NPK + Compost, and no fertilization (control). Soil physical properties were investigated at rice harvesting stage in the 41st year for analyzing the relationship with SOC fraction. Continuous compost application increased the total SOC concentration in plough layers and improved soil physical properties. In contrast, inorganic or no fertilization markedly decreased SOC concentration resulting to a deterioration of soil physical health. Most of the SOC was the organo-mineral fraction (<0.053 mm size), accounting for over 70% of total SOC. Macro-aggregate SOC fraction (2–0.25 mm size), which is used as an indicator of soil quality rather than total SOC, covered 8–17% of total SOC. These two SOC fractions accumulated with the same tendency as the total SOC changes. Comparatively, micro-aggregate SOC (0.25–0.053 mm size), which has high correlation with physical properties, significantly decreased with time, irrespective of the inorganic fertilizers or compost application, but the mechanism of decrease is not clear. Conclusively, compost increased total SOC content and effective SOC fraction, thereby improving soil physical properties and sustaining production.     

Declining birds in Australian agricultural landscapes may benefit from aspects of the European agri-environment model

Temperate Australia’s wheat/sheep zone and much of Western Europe have both experienced dramatic declines in native bird populations associated with agricultural landscapes. We compare recent conservation strategies on private land in the context of each region’s historical agricultural development and the ecology of its bird fauna. Specifically, we consider which aspects of the conservation instruments and practices employed in European agricultural landscapes might be used to augment and inform approaches to private-land biodiversity conservation in Australia. Australian biodiversity conservation activities have focussed predominantly on remnant native vegetation and rarely target the agricultural matrix (i.e. land that is primarily used for agricultural production). However, declining species include those that not only primarily inhabit woodland, but also species for which components of the agricultural matrix are important, or even their main, habitat. In contrast, in Europe a range of conservation activities undertaken through agri-environment schemes focus explicitly on the management of the agricultural matrix. Whilst the different approaches to conservation on private land in Australia and Europe reflect the two continents’ different ecologies, land-use histories and political economies of agriculture, there are a number of parallels between bird population declines in the two regions, and an opportunity may exist to incorporate some of the successful aspects of the European agri-environment approach into emerging stewardship schemes in Australia. We suggest that the long-term nature of European agri-environment agreements, the principle of landholder payments more commensurate with reduced production opportunity and management actions specifically targeted at the agricultural matrix, are features of the European scheme that could benefit both woodland- and matrix-inhabiting bird species in Australian agricultural landscapes.     

Effect of a fly ash and gypsum mixture on rice cultivation

Abstract

The salt titration (ST) method was evaluated as a method to determine ZPC in comparison with the potentiometric titration (PT) method for 26 soils with variable charge clays, i.e., Oxisols and Ultisols from Thailand and Andisols from Japan. In addition to the determination of ST-pH₀ as the zero point of charge, a calculation procedure (STPT method) was adopted here in order to acquire more information from the titration curve. Furthermore, for the purpose of cross-checking of ZPC determined by the PT method, the ST procedure was successively applied to the samples analyzed by the PT method (PTST method).

The soil to solution ratios of 1: 10 to 1: 5 gave almost an identical ST-pH₀ value for every soil. The values of both ST-pH₀ and PT-ZPC ranged from 4.7 to 6.3 for the Andisols, while for the Oxisols and Ultisols, they were always below 4.2. The difference between the values of ST-pH₀ and PT-ZPC was only slight for the Andisols, whereas it was sometimes large (0.4 pH unit) for the Oxisols and Ultisols. Nevertheless, it was concluded that the ST method with its modification (STPT) was comparable to or even better than the PT method for the soil characterization work due to its convenience and simplicity.     

Comparison of Surface-Modified Adsorbents for Phosphate Removal in Water

Three novel composite adsorbents, sulfate-coated zeolite (SCZ), hydrotalcite (SCH), and activated alumina (SCAA), were characterized and employed for the removal of phosphate from aqueous solution using equilibrium and kinetic batch experiments. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction spectrum were used to study the surface characteristics of the coated layer. Equilibrium tests showed that the adsorption of phosphate followed both Langmuir and Freundlich isotherms. The powder-type SCZ was better for phosphate removal (maximum binding energy, ???=?111.49?mg?g^?1) compared to hydrotalcite and activated alumina. The adsorption of phosphate was considered to take place mainly by ion exchange. The kinetic data followed a pseudo-second-order kinetic model. The initial adsorption of phosphate onto the sulfate-coated adsorbents was fast, indicating that the sulfate-coated materials developed in this study can be used as promising adsorbents for the removal of phosphate from wastewater or sewage.     

Development of an ELISA for the detection of the residues of the fungicide iprovalicarb

A competitive indirect enzyme-linked immunosorbent assay was developed for the fungicide iprovalicarb, using a polyclonal antibody produced against a hapten conjugated through the carboxyl group on the benzene ring to keyhole limpet hemocyanin. Under an optimized condition using a heterologous format, an IC(50) of 3.51 ng/mL and the lowest detection limit of 0.065 ng/mL were obtained. When the isopropoxy group was removed from the iprovalicarb structure for the synthesis of a hapten, the resulting hapten was not successful as an immunogen, indicating that the isopropyl moiety was an important epitope, as evidenced by the cross-reactivities of some structurally related compounds. When applied to the real crop and water samples, the recoveries were in the range of 80.52-144.70% (n = 4) and 72.11-100.43% (n = 4), respectively. Accordingly, this ELISA can be used as a useful method for monitoring iprovalicarb residues in crop and water samples.     

Further monitoring for Salmonella species and Escherichia coli O86 at a bird table in south-west Scotland

Pooled faeces collected from a garden bird table were screened for Salmonella species and Escherichia coli O86, two recognised causes of garden bird mortality. Dead birds found at the site were also screened for these organisms, and bird numbers and meteorological data were recorded. In the first year of the study, 48.5 per cent of the samples were positive for Salmonella Typhimurium DT56 (variant), decreasing to 38.9 per cent in the second year and 12.8 per cent in the third year. E. coli O86 was not recovered from any of the 288 samples of pooled faeces tested. S. Typhimurium DT56 (variant) was recovered from the carcases of eight birds found dead at the site, and E. coli O86 was isolated from three carcases. The degree of contamination of the bird table with S. Typhimurium DT56 (variant) was positively correlated with the number of house sparrows observed in the garden, but not with the number of blackbirds, chaffinches or greenfinches.     

Antioxidant activity and characterization of volatile constituents of Taheebo (Tabebuia impetiginosa Martius ex DC)

Volatiles were isolated from the dried inner bark of Tabebuia impetiginosa using steam distillation under reduced pressure followed by continuous liquid-liquid extraction. The extract was analyzed by gas chromatography and gas chromatography-mass spectrometry. The major volatile constituents of T. impetiginosa were 4-methoxybenzaldehyde (52.84 microg/g), 4-methoxyphenol (38.91 microg/g), 5-allyl-1,2,3-trimethoxybenzene (elemicin; 34.15 microg/g), 1-methoxy-4-(1E)-1-propenylbenzene (trans-anethole; 33.75 microg/g), and 4-methoxybenzyl alcohol (30.29 microg/g). The antioxidant activity of the volatiles was evaluated using two different assays. The extract exhibited a potent inhibitory effect on the formation of conjugated diene hydroperoxides (from methyl linoleate) at a concentration of 1000 microg/mL. The extract also inhibited the oxidation of hexanal for 40 days at a level of 5 microg/mL. The antioxidative activity of T. impetiginosa volatiles was comparable with that of the well-known antioxidants, alpha-tocopherol, and butylated hydroxytoluene.     

Evaluation of enhanced hygroscopicity, bifidogenicity, and anticariogenicity of enzymatically synthesized beta-galactosyl-trehalose oligosaccharides

beta-Galactosyl-trehalose oligosaccharides (beta-GTOs) were enzymatically prepared as a mixture of 6-beta-galactosyl-trehalose (1) and 4-beta-galactosyl-trehalose (2) with a 9:1 ratio (w/w). The beta-GTO mixture showed a highly enhanced hygroscopicity as compared to those of trehalose and other sugars used. At 72 h of incubation under 90% relative humidity and room temperature, it had a large increase in weight due to its moisture absorption, which was five times larger than that of trehalose, 1.9 times larger than that of sucrose, and 1.5 times larger than that of maltotriose. It was very effective in the growth promotion of Bifidobacteria, such as Bifidobacterium longum and Bifidobacterium bifidum, which was better than the growth promotion in the cases of trehalose and galactooligosaccharide. It also showed a highly anticariogenic property; it had only 10% cell proliferation of Streptococcus sobrinus for that of the sucrose control and 60% inhibition of insoluble glucan synthesis. Its effectiveness of inhibition was two and 1.5 times better than that of trehalose and one and two times than xylitol, respectively, against cell growth and glucan synthesis. Conclusively, the functionality of the beta-GTO in terms of hygroscopicity, bifidogenicity, and anticariogenicity was considerably improved as compared to that of trehalose. It is thus suggested that the beta-GTO might be applied as an effective humectant and prebiotic substitute with enhanced noncariogenicity in food applications.     

Analysis of physicochemical factors related to the automatic pellicle removal in Korean chestnut (Castanea crenata).

Analyses were carried out for condensed tannin content, soluble sugar content, color, firmness, and peeling ratio of the pellicle of 14 varieties of Korean chestnut. The correlation between these physicochemical components and the peeling ratio was measured. The total soluble sugar content ranged from 4.20 to 11.83%. Condensed tannin contents in the inner and outer chestnut shells were 7.83-71.42% and 0.31-2.04%, respectively. In the outer shell of chestnut, CIE L* value was 26.98-33.34, CIE a value was 7.56-14.90, and CIE b value was 7.36-15.67. Firmness of chestnut was 4.41-9.20 kg. Peeling ratio of the pellicle by the peeling machine was significantly different with variety. The average peeling ratio was 63.79%, and that of the Okkwang variety was the highest at 85.29%. A negative correlation was found between tannin content of inner shell and peeling ratio (r = -0.57), but the correlation coefficients between other components and the peeling ratio were not significant.