Filter Paper Method Research Articles

An Analysis of Vertical Infiltration Responses in Unsaturated Soil Columns from Permafrost Regions

Rainfall infiltration affects permafrost-related slope stability by changing the pore water pressure in soil. In this study, the infiltration responses under rainfall conditions were elucidated. The instantaneous profile method and filter paper method were used to obtain the soil–water characteristic curve (SWCC) and hydraulic conductivity function (HCF). During the rainfall infiltration test, the vertical patters of volumetric moisture contents, total hydraulic head or suction and wetting front were recorded. Advancing displacement and rate of the wetting front, the cumulative infiltration, the instantaneous infiltration rate, and the average infiltration rate were determined to comprehensively assess the rainfall infiltration process, along with SWCC and HCF. Additionally, the effects of dry density and runoff on the one-dimensional vertical infiltration process of soil columns were evaluated. The results showed that the variation curve of wetting front displacement versus time obeys a power function relationship. In addition, the infiltration rate–time relationship curve and the unsaturated permeability curve could be roughly divided into three stages, and the SWCC and HCF calculated by volumetric moisture content are more sensitive to changes in dry density than to changes in runoff or hydraulic head height.

Are Biobased Microfibers Less Harmful than Conventional Plastic Microfibers: Evidence from Earthworms.

Biobased plastics are sometimes promoted as "environmentally friendly" compared to their conventional petrochemical-based counterparts, but their ecotoxicity is only partially understood. Biobased fibers are widely used in clothing and wet wipes and can accumulate in soils through the application of biosolid fertilizers. This study examined the lethal thresholds and sublethal toxicity of chemically characterized, additive-free, biobased (viscose and lyocell) compared to petrochemical-based (polyester) fibers on the key ecosystem engineer, Esenia fetida. Viscose and lyocell had LC20 values of 14.00 and 22.66 mg·L-1, respectively, and no observed effect concentrations (NOEC) of 0-2.8 mg·L-1 (72 h, OECD TG207 filter paper method), while for polyester these were LC20 15.6-31.3 mg·L-1 and NOEC 0-15.6 mg·L-1. Following 28 days of exposure to soils (OECD TG222) contaminated with environmentally relevant concentrations (100 mg kg-1), viscose significantly reduced the mass of progeny compared to polyester. Earthworms exposed to lyocell had a marginal growth reduction (-18%; compared to -11% to -13% in other treatments) linked to increased bioturbation activity. The biobased fibers examined here have greater acute toxicity at high concentrations and broadly similar sublethal effects on E. fetida compared to polyester. Our study highlights the importance of detailed testing before advocating specific materials as plastic alternatives/substitutes to conventional plastics.

Impact of high‐intensity ultrasound, cooling rate, and storage temperature on physical properties and oil binding capacity in fully hydrogenated palm‐kernel lipid matrices

AbstractThe ability of a fat crystal network to entrap liquid oil is known as oil binding capacity (OBC) and is an imperative property in semi‐solid fats for use in confectionary, bakery, and snack products. Understanding the factors that increase the OBC of fats is crucial for developing fat‐based foods that are more resistant to unwanted oil migration. In this study, fully hydrogenated palm‐kernel based (FHPKO) lipid matrices were crystallized under different processing conditions to generate samples with a wide range of physical properties and OBC. Three dilutions were created by combining FHPKO with soybean oil (SBO)—75% FHPKO (containing 25% SBO), 50% FHPKO (50% SBO), and 20% FHPKO (80% SBO) and were crystallized at 33, 30, and 22°C; respectively. All the samples were crystallized using fast (FCR; 4.6°C/min) and slow (SCR; 0.1°C/min) cooling rates, as well as with (w) and without (wo) high‐intensity ultrasound (HIU; 20 kHz). These processing conditions resulted in four different sets of samples—FCR wo HIU, FCR w HIU, SCR wo HIU, SCR w HIU. Immediately after processing, the sample's hardness, solid fat content (SFC), viscoelasticity (G′, G″, δ), microstructure, melting behavior (Tpeak, enthalpy), and OBC using a centrifuge method (labeled OBCc) were analyzed. Samples were then stored at 22 and 5°C for 48 h and the aforementioned properties were measured again as well as OBC using a filter paper method (labeled OBCp). Results show that both OBCc and OBCp were positively correlated with the sample's SFC (rs = 0.912, p < 0.001; rs = 0.777, p < 0.001), storage moduli (G′) (rs = 0.674, p < 0.001; rs = 0.526, p = 0.017), hardness (rs = 0.793, p < 0.001; rs = 0.812, p < 0.001), enthalpy (rs = 0.842, p < 0.001; rs = 0.812, p < 0.001), and the number of crystals (rs = 0.655, p < 0.001; rs = 0.728, p < 0.001); respectively. While no correlation between OBCp and the sample's peak melting temperature and microstructure was recorded, a negative association between the sample's peak melting temperature (rs = −0.782, p < 0.001), phase angle (δ) (rs = −0.801, p < 0.001), and crystal diameter (rs = −0.470, p = 0.004) was documented for OBCc. These results suggest oil binding capacity of palm‐kernel based crystallized fats can be increased by formulating harder fats that are elastic, contain more crystals, and have higher SFC and enthalpy. Additionally, the FCR with HIU processing conditions was the most effective in increasing the OBC.

Effects of Salt Stress on Seed Germination and Embryo Growth of Oxytropis coerulea

Background: Oxytropis coerulea is considered to be an exceptional forage. The salinization of soil is a prevalent ecological issue worldwide. In order to study the effects of saline solution on seed germination and embryo growth of O. coerulea. Methods: An experiment was carried out using the culture dish filter paper method. Three salt stresses, namely, Na2CO3, NaCl and double salt were set, each of which was set to 0%, 0.3%, 0.6% and 0.9% concentration. Result: The results indicated that as the concentration of salt increased, there was a decrease in the germination rate, germination index and embryo growth. The activities of SOD, POD and CAT, as well as soluble protein content, initially increased and then decreased with increasing salt stress. The toxic effects of the three salts ranged from strong to weak as Na2CO3 greater than double salt greater than NaCl. The salt resistance indexes of 0.3% Na2CO3, NaCl and double salt were 53.87, 57.00 and 38.73, respectively and the salt resistance index of 0.6% NaCl was 50.21, indicating a high salt-tolerant degree. It showed certain resistance to 0.3% Na2CO3, 0.6% NaCl and 0.3% double salt. In short, the various soluble mechanisms of O. coerulea in different stages of salt stress and different salt stress levels have different reaction mechanisms, which reflect the salt stress of O. coerulea seeds. O. coerulea seeds can be planted in a suitable concentration of saline-alkali land, which can utilize the feed value and medicinal value of O. coerulea to improve economic benefits and utilize saline soil to improve the ecological environment.

Evaluating the Efficacy of Plant Extracts in Managing the Bruchid Beetle, Callosobruchus maculatus (Coleoptera: Bruchidae).

An estimated 2000 plant species have been employed for pest control worldwide. The use of these botanical derivatives is thought to be one of the most cost-effective and sustainable options for pest management in stored grain. The present study was designed to assess the efficacy of five plant extracts viz; Nicotiana tabacum L., Nicotiana rustica L., Azadirachta indica A. Juss., Thuja orientalis L., and Melia azedarach L. against Callosobruchus maculatus L. Plant species extracts were applied at six different concentrations, i.e., 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0% in four replications. The phytochemical analyses of ethanolic extracts of five plant species showed variable amounts of phytochemicals i.e., alkaloids, flavonoids, saponins, diterpenes, phytosterol, and phenols. Total phenolic and flavonoid compounds were also observed. The efficacy of A. indica was highest, characterized by the lowest infestation rate (16.65%), host seed weight loss (7.85%), mean oviposition (84.54), and adult emergence (58.40%). In contrast, T. orientalis was found to be the least effective against C. maculatus, with the highest infestation rate of 25.60%, host seed weight loss of 26.73%, mean oviposition of 117.17, and adult emergence rate of 82.01%. Probit analysis was performed by estimating LC50 and LC90. The toxicity percentages of N. tabacum (LC50 = 0.69%, LC90 = 14.59%), N. rustica (LC50 = 0.98%, LC90 = 22.06%), and A. indica (LC50 = 1.09%, LC90 = 68.52%) were notable in terms of the lower LC50 and LC90 values after the 96-h exposure period against C. maculatus. Repellency was assessed by using the area preference and filter paper method. The repellency of C. maculatus on plant extracts increased with the increasing dose and time, such that it was the highest after 48 h. Likewise, at a 3% concentration, A. indica demonstrated 100.00% (Class-V) repellency followed by N. tabacum (96.00%, Class-V), N. rustica (74%, Class-IV), M. azedarach (70.00%, Class-IV), and T. orientalis (68.00%, Class-IV). Based on the findings of this study, we recommend integrating N. rustica, N. tabacum, A. indica, and M. azedarach for effective management of C. maculatus and highlight the potential of these plant species in the formulation of new biocidal agents.

Exploring the Prevalence of HPV Genotypes in Women of Northeast India using the Dry Filter Paper Method and Correlation with Pap Test Findings in Low Resource Setting

Exploring the Prevalence of HPV Genotypes in Women of Northeast India using the Dry Filter Paper Method and Correlation with Pap Test Findings in Low Resource Setting

Model Modification of the Soil–Water Characteristic Curve of Unsaturated Weak Expansive Soil

This study evaluates the impact of compaction on the soil–water characteristic curve of unsaturated remodeled weakly expansive soils by assessing changes in soil pore structure resulting from variations in compaction. The remodeled weakly expansive soil in the Xinjiang Hami area is taken as the research subject to investigate how compaction affects microscopic pore structure using mercury intrusion testing. Subsequently, mercury intrusion porosimetry is employed to examine pore structure and distribution patterns at different dry densities. Based on the capillary principle and experimental methods (filter paper method and pressure plate method test), modified soil–water characteristic curves are obtained by fitting them with a three-parameter model law. The results indicate that higher dry density leads to an increased air intake value and significantly reduces the total volume of large pores within samples. Both the Fredlund and Xing model and the three-parameter model effectively capture the influence of initial dry density on the development pattern of the soil–water characteristic curve.

Water retention property and microscopic mechanism of shallow soil in inner dump improved by fly ash and polyacrylamide.

Improving the water retention property of shallow soil in the inner dump is the key step in the sustainable development of mines. In recent years, the use of fly ash to improve the structure of the inner dump and polyacrylamide as an additive to enhance water retention was an effective method. The article used a physical model test, filter paper method, and microstructure analysis method to compare and analyze the water retention property and microstructure of slope-improved soil with different fly ash and polyacrylamide content. The results show that the combined use of fly ash and polyacrylamide improved the water retention property of the amended soil. Fly ash and polyacrylamide had a greater effect on the low suction stage of the amended soil. Polyacrylamide reacted with water and bound soil particles to form aggregates, and the structural unit bodies were a block structure. Fly ash was non-sticky and was a matrix of fine particles, which weakened the bonding effect of polyacrylamide, and reduced the aggregates of soil particles, and the structural unit bodies were a flocculated structure of aggregates mixed with matrix. This, in turn, enhanced the capillary action and improved the water retention performance of the improved soil. In addition, polyacrylamide could connect water molecules, further enhancing the water retention property of the improved soil. The combined use of fly ash and polyacrylamide improved the available water content of improved soil, providing a viable and sustainable solution for improving the comprehensive utilization of fly ash, and laid the foundation for land reclamation at the inner dump.

Current Status and Issues Regarding Specimen Collection Using Dry Filter Paper Method in Clinical Pharmacology Research and Routine Medical Care: Scoping Review

Current Status and Issues Regarding Specimen Collection Using Dry Filter Paper Method in Clinical Pharmacology Research and Routine Medical Care: Scoping Review

Allelopathic Potential of Some Dominating Weeds Associated with Winter Crops

Experiments were conducted to investigate the allelopathic potential of some dominating weeds (Coronopus didymus L., Trianthema portulacastrum L., Malvastrum coromandelianum L., Cirsium vulgare (Savi) Ten. and Chenopodium album L.) on winter crops i.e., pea (Pisum sativum L.), spinach (Spinacia oleracea L.), wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). The effects of different concentrations (0.5%, 1% and 2%) of weeds’ extracts were recorded using filter paper method. The extracts of Malvastrum coromandelianum and Cirsium vulgare significantly reduced the seed germination, hypocotyl and radicle growth of spinach. Hypocotyl and radicle growth of barley was highly inhibited under the influence of the extracts of Chenopodium album while the same species stimulated the seedling growth and germination of spinach at its all concentrations. The effects were found to be concentration dependent. The results have indicated that M. coromandelianum and C. vulgare are not suitable near other crops due to their adverse effects on crops. It was concluded that these species are not suitable in an intercropping system. Moreover, their plantation should be carefully assessed with in the crop field.

Entomopathogenic fungi against the dengue vector Aedes aegypti: laboratory and semifield assessment

Aedes aegypti, in addition to its association with arboviruses of significant public health concern, poses a considerable challenge to the scientific community, which is actively working to devise innovative strategies to address this threat. Entomopathogenic fungi (EPF) are important bioagents for insect pest control. This study aimed to evaluate the virulence of EPF against Ae. aegypti larvae and adults under laboratory and semifield conditions. Conidia powder from M. anisopliae CG 153 or B. bassiana CG 479, at concentrations ranging from 1×105 to 1×108 conidia/mL, was tested against larvae (N=30) under laboratory conditions, while conidia suspension was used against adults (N=30) via the impregnated filter paper method. Survival curves were compared using the Log-rank test. Both isolates exhibited virulence against larvae and adults, with survival rates ranging from 0% to 64% and 20% to 76%, respectively. Subsequently, both fungi, at a concentration of 107 conidia/mL, were tested against larvae (N=60) and adults (N=60) under laboratory and semifield conditions. Under semifield conditions, larvae and adults showed survival rates ranging from 12% to 35% and 5% to 20%, respectively. The semifield tests produced promising results in decreasing mosquito survival rates. Consequently, this study concludes that the isolates M. anisopliae CG153 and B. bassiana CG 479 have the potential to serve as eco-friendly insecticides against mosquitoes, thus warranting further exploration in the bioprospecting of EPF-based products.

Saturated permeability and water retention capacity in biochar-methanotrophs-clay for new landfill cover system

A new landfill cover system, biochar-methanotrophs-clay (BMC) cover is recommended for reducing methane emissions at landfills. It also contributes to decreasing soil permeability and improving soil water retention in a long time, due to highly porous structure of biochar and the growth metabolism of methanotrophs. To determine the effects of biochar content, oxidation aging times and methane-filled days on hydraulic properties, a total of 60 groups of experiments were conducted. The saturated hydraulic conductivity (ksat) was obtained by flexible wall permeameter with controllable hydraulic head pressure. The results showed that the ksat of BMC increased with increasing biochar content and oxidation aging times, while decreased with adding methane-filled days. The soil-water characteristic curves (SWCCs) were obtained with soil suction measured by the filter paper method. The results indicated the water retention capacity of MBC reduced with increasing oxidation aging times but increased with adding methane-filled days. Detected by mercury intrusion porosimetry (MIP), fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM), the differences displayed the changes of pore structures and extracellular polymeric substances (EPS). The oxidation aging of biochar increased the volume of pores, resulting in the increased ksat and the decreased water retention capacity. However, the growing of methanotrophs decreased the volume of pores, resulting in the ksat decreased and the water retention capacity increased due to EPS. No matter how many times the oxidation aging process was experienced, the BMC with longer methane-filled days exhibited relatively lower ksat and better water retention capacity. This implied a more stable barrier capacity to reduce water infiltration in the long term. By combing a series of macro and micro experiments, this paper provides theoretical guidance for the application of biochar-methanotroph-clay mixture to landfill covers.

Unveiling the physical properties predictive of oil binding capacity in an interesterified palm‐based fat

AbstractThis paper identifies physical properties of an interesterified palm‐based fat (EIEPO) that predict oil binding capacity (OBC). A 100% EIEPO sample, 50% EIEPO sample diluted with 50% soybean oil (SBO), and a 20% EIEPO sample diluted with 80% SBO were used to test how saturation level impacts OBC. All samples were crystallized using either a fast (6.4°C/min) or slow (0.1°C/min) cooling rate as well as with or without the application of high‐intensity ultrasound (HIU; 20 kHz) to generate a wide range of physical properties. Immediately after crystallization, the sample's physical properties, including crystal microstructure, solid fat content (SFC), viscoelasticity (G′, G″, and δ), melting behavior, hardness, and OBC (centrifuge method) were quantified. The samples were then stored for 48 h at 22 and 5°C and the aforementioned physical properties were measured again, with one additional measurement for the samples stored at 5°C—OBC using a filter paper method (OBCp). The results indicate that OBC can be optimized in a palm‐based fat by modifying the physical properties which was achieved via the processing conditions. Both measurements of OBC were significantly correlated with SFC, hardness, δ, and enthalpy. A model was developed to predict a sample's OBCc using the following dominant variables—SFC, hardness, peak temperature, enthalpy, and the number of crystals. These results suggest that OBC can be predicted using a sample's SFC, hardness, peak temperature, enthalpy, and number of crystals and that SFC, hardness, and enthalpy are main drivers of OBC.

DETERMINATION OF THE MATRIX SUCTION OF LOW-PLASTICITY SILTS AND ITS CORRELATION WITH THEIR COLLAPSE POTENTIAL

Soils are usually in a partially saturated state, meaning that both air and water occupy their voids. This condition can affect the stability of structures because it is closely related to wetting deformation (collapse). A low-plasticity silt (ML) composed of 45% kaolin with a liquid limit of 36% and a plasticity index of 10% was used in this study. In this study, the soil suction matrix was determined using the filter paper method established in ASTM D5298, correlating it with the moisture content and percentage of deformation induced by wetting. It was concluded that, as the moisture content decreases, the suction and the percentage of deformation by wetting increase, since, for a moisture content of 9% the suction is 14901.6 kPa and the deformation is 0.58%, while for a moisture content of 21% the suction is 1028.1 kPa and the deformation is 0.07%. Thus, a change in the slope of the SWRC was evident starting at 9%, which indicates a greater effect of suction and deformation below this moisture content.

Exploring the diversity, bioactivity of endophytes, and metabolome in Synsepalum dulcificum.

Synsepalum dulcificum exhibits high edible and medicinal value; however, there have been no reports on the exploration of its endophyte resources. Here, we conducted analyses encompassing plant metabolomics, microbial diversity, and the biological activities of endophytic metabolites in S. dulcificum. High-throughput sequencing identified 4,913 endophytic fungal amplicon sequence variants (ASVs) and 1,703 endophytic bacterial ASVs from the roots, stems, leaves, flowers, and fruits of S. dulcificum. Fungi were classified into 5 phyla, 24 classes, 75 orders, 170 families, and 313 genera, while bacteria belonged to 21 phyla, 47 classes, 93 orders, 145 families, and 232 genera. Furthermore, there were significant differences in the composition and content of metabolites in different tissues of S. dulcificum. Spearman's correlation analysis of the differential metabolites and endophytes revealed that the community composition of the endophytes correlated with plant-rich metabolites. The internal transcribed spacer sequences of 105 isolates were determined, and phylogenetic analyses revealed that these fungi were distributed into three phyla (Ascomycota, Basidiomycota, and Mucoromycota) and 20 genera. Moreover, 16S rDNA sequencing of 46 bacteria revealed they were distributed in 16 genera in three phyla: Actinobacteria, Proteobacteria, and Firmicutes. The antimicrobial activities (filter paper method) and antioxidant activity (DPPH and ABTS assays) of crude extracts obtained from 68 fungal and 20 bacterial strains cultured in different media were evaluated. Additionally, the α-glucosidase inhibitory activity of the fungal extracts was examined. The results showed that 88.6% of the strains exhibited antimicrobial activity, 55.7% exhibited antioxidant activity, and 85% of the fungi exhibited α-glucosidase inhibitory activity. The research suggested that the endophytes of S. dulcificum are highly diverse and have the potential to produce bioactive metabolites, providing abundant species resources for developing antibiotics, antioxidants and hypoglycemic drugs.

Impact of modifiers on soil–water characteristics of graphite tailings

To achieve integrated resource utilization of graphite tailings to improve their water-holding capacity, river silt and cow dung powder were added to graphite tailings as organic matter improvers. Improver ratios were designed using 4 g cow dung powder and 20, 30, and 50 g river silt. Soil–water characterization tests were performed using a combined tensiometer and filter paper method based on optimum density measurements. Analysis of the influence of river silt dosing on the soil–water characteristic curves of improved graphite tailing specimens was performed with data fitting using the Van Genuchten model. Here, we investigated the effect of river silt dosing on the internal pore structure and water-holding capacity of modified graphite tailing samples and verified the applicability of the model to graphite tailings. Our results demonstrate that the organic matter improver incorporated into graphite tailings can improve the internal structural compactness of graphite tailings, improving the water holding capacity. With an increase in river silt dosage, the saturated water content is larger, and the residual water content increases and then decreases. When river silt dosage is 30 g, the residual water content is the highest at a value of 3.32%. The van Genuchten model was highly accurate for assessing the graphite tailings. With an increase in river silt doping, the internal pore space first decreased and then increased, and the internal structure gradually became compact and loosened. The internal structure was in the optimal state in the experimental study when the dosage of cow dung powder was 4 g and the dosage of river silt was 30 g. The water holding capacity was optimal at this time. The results of this study provide a theoretical foundation for graphite-tailing-based mine reclamation and play a guiding role in exploring the value of the hydraulic characteristic index parameters when applying graphite tailings engineering.

Thermal Effects on the Soil Water Retention Curves and Hydraulic Properties of Benggang Soil in Southern China

Soil hydraulic properties significantly affect the occurrence and development of collapsing gully walls. The effect of temperature on the hydraulic properties of soil in collapsing gully walls remains unclear. In this study, the hydraulic properties of the red soil layer, the sandy soil layer and the detritus layer in a collapsing gully wall were investigated using the filter paper method, and the soil water retention curves of the different soil layers at 25 and 40 °C were determined. The aim of this study was to investigate the impact of temperature on the soil hydraulic properties of different soil layers in collapsing gully walls. The study found that when the water content in the red soil layer and sandy soil layer exceeded 20% and in the detritus layer exceeded 10%, the soil’s matric suction significantly decreased as the temperature increased from 25 to 40 °C. Additionally, the parameters of θs, α, n and m all exhibited a decreasing trend, and the soil water content in the detritus layer was primarily influenced by the temperature change, which resulted in a decrease of 38.10%. The unsaturated hydraulic conductivity of the detritus layer exhibited higher values than that of the sandy layer and red soil layer under identical temperature conditions. Moreover, the unsaturated hydraulic conductivity of the red soil layer, sandy soil layer and detritus layer increased with increasing temperature. It was observed that the unsaturated hydraulic conductivity of the detritus layer increased by 0.18 cm h−1 at a soil water content of 44%. This increase in conductivity was more pronounced than the corresponding changes in the red soil layer and sandy soil layer. An elevated temperature caused the water-holding capacity of the different soil layers of the collapsing gully wall to decrease and the unsaturated hydraulic conductivity to increase. However, the influence of the clay particle content within the soil of the collapsing gully wall rendered the temperature effect more distinct. Therefore, the destabilizing deformation of the soil in the collapsing gully wall during the summer under high temperatures and precipitation may have played a key role in its collapse.

Reliability of Soil Water Characteristics Curve under Different Normal Stresses for Unsaturated Sand

The soil water characteristics curve (SWCC) demonstrates a link between soil moisture content and suction. The SWCC is almost treated as an index parameter in unsaturated soil. The soil permeability and shear strength can be linked to SWCC. SWCC is established using filter paper for the wetting path. This paper compares SWCC for both cases stress-dependent and no stress (reference) in the wetting path. The samples of soil are brought from Al-Najaf City with a gypsum content of 29%, Iraq. The stress-SWCC is studied using a modified Oedometer cell with controlled water and air entrance to apply a specific matric suction. While the reference SWCC is estimated using the filter paper method. Matric suction is conducted at a range of pressures from 90 kPa to 0 kPa. The tests use three net normal stresses of 100, 200, and 400 kPa. The results show that there are decreasing values of the SWCC with increasing normal stresses. An interesting result is that this decrease is high and has zero matric suction. The water entry value (WEV) with the most significant value of the water entry change is represented by the matric suction of 50 kPa.

A Simple, Affordable, Do-It-Yourself Method for Measuring Soil Maximum Water Holding Capacity

ABSTRACT There is an increasing need for accessible methods to monitor soil health. Our primary objective was to evaluate an accessible, do-it-yourself method for measuring the maximum water holding capacity – we call this the funnel, filter paper, and drainage (MWHCFFPD) method. First, we compared MWHCFFPD to the water desorption method via pressure cells (WHCPC), routinely used for generating soil water retention curves, using 10 soils from a wide range of textures (4–55% clay). Second, we tested the sensitivity of the MWHCFFPD to methodological variations likely encountered by citizen scientists. The two methods were quite comparable in precision, with mean coefficient of variances of 3.5% and 4.4% for the FFPD and water desorption method, respectively. The MWHCFFPD and WHCPC methods were comparable, with MWHCFFPD best correlating to WHCPC at −2.45 kPa (R2 = 0.98). The MWHCFFPD method is somewhat sensitive to some methodological modifications, most notably variation in water source, but with standardized protocols could be scientifically robust. Overall, MWHCFFPD can be used as a simple and affordable test of sieved soil structure and organic matter, and thus has potential to expand soil health monitoring.

New variants of AvrPiz-t identified in Pyricularia oryzae from Malaysia

Rice blast disease (causal agent: Pyricularia oryzae) is an important rice disease worldwide as it can cause significant yield loss. Resistance genes in rice can recognise the corresponding avirulence genes (Avr-gene) of P. oryzae and suppress the attack of the pathogen as proposed in ‘gene-for-gene’ interaction. This interaction is highly specific. The resistance will be rapidly breakdown owing to the plasticity of Avr-gene. The breaking down of disease resistance can cause problem in managing the disease as well as sustaining a resistant rice variety. This paper aimed to study and analyse the sequence variation of AvrPiz-t gene from P. oryzae isolates in Malaysia (Sarawak) together with AvrPiz-t sequences available from National Centre for Biotechnology Information (NCBI). This study compared the AvrPiz-t haplotype found with previously reported haplotypes. A total of 20 Malaysian P. oryzae isolates were obtained from six divisions of Sarawak and were verified using internal transcribed spacer. Together with seven Malaysian P. oryzae isolates from a previous study, a total of 27 AvrPiz-t gene sequences from Malaysian isolates were successfully amplified and verified. The AvrPiz-t open reading frame (ORF) of 27 Malaysian isolates were aligned with 123 AvrPiz-t ORF from other countries that were available in NCBI database and 100 AvrPiz-t ORF from a previous study (Total = 250 sequences). Unique sequences were identified and translated into amino sequence. The amino acid sequences were aligned with haplotype sequences from previous studies. In total, there were 19 AvrPiz-t haplotypes, with eight newly identified haplotypes. The AvrPiz-t haplotypes were distributed across 14 countries with haplotype H9 as the dominant haplotype. Neutrality tests were performed for the 250 AvrPiz-t ORF sequences. The 250 isolates of P. oryzae were undergoing directional natural selection.. Detached leaf inoculation using filter paper method of selected Malaysia (Sarawak) P. oryzae isolates carrying one of the new AvrPiz-t haplotypes showed different level of pathogenicity towards Sarawak rice landraces. The data obtained serves as baseline information for disease management in Malaysia, especially for Sarawak state. Additionally, the information is also a reference for future rice breeding program in Sarawak.