Changes in soil conditions before and after earthquakes at a repetitive soil liquefaction site in Taiwan

Beishih Village of Hsinhua Township in southern Taiwan is a unique location for studying soil liquefaction. Soil liquefaction was observed at the same site after earthquakes in 1946, 2010, and 2016, each of which had a Richter magnitude greater than six. This recurrence provides an opportunity for analyzing soil condition variations resulting from soil liquefaction. Seismic data sets were collected in 2011, 2014, 2016, and 2017. We used seismic refraction tomography and the multichannel analysis of surface waves to estimate P- and S-wave velocities. In S-wave velocity profiles, low shear velocity zones were located beneath sand volcanoes shortly after two earthquakes and disappeared 4 years after a 2010 earthquake. However, the P-wave velocity is less sensitive to soil condition changes, possibly because groundwater obscures the effect of soil liquefaction on velocity profiles. In addition, we used seismic wave velocities to determine the importance of soil properties such as Poisson’s ratio, shear modulus, and porosity to identify the cause of the low shear velocity zone. Notably, although porosity decreased after soil grain rearrangement, sand and clay mixing increased the Poisson’s ratio, reducing the shear modulus of the soil. In addition, a soil layer between 2 and 7 m and a deeper layer below 10 m that resulted in sand volcanoes were both liquefied. We also considered how the evaluation of soil liquefaction potential could be affected by long-term variations in soil conditions and changes resulting from liquefaction. The factor of safety was used to evaluate the liquefaction potential of the site. The results revealed that the assessment conducted long after the earthquake underestimated risk because the soil developed shear strength after the earthquake.

Decomposition of rice straw residues and the emission of CO2, CH4 under paddy rice and crop rotation in the Vietnamese Mekong Delta region – A microcosm study

This study investigated the influence of soil undergoing different crop rotations on the CH₄, CO₂ emissions, and decomposition of rice straw. The studied soil undergoing crop rotation systems were rice-rice-rice (SR) and baby corn-rice-mungbean (SB). Two main microcosm set-ups: anaerobic (SR-AN, SB-AN) and aerobic (SR-AE, SB-AE) conditions. Litter bags containing rice stems were inserted into the soil and recollected at different time points for chemical analysing and the gas sampling was collected to measure the CO₂ and CH₄ emissions. The results indicated that the total carbon (TC) decreased around 30%, and the TC removal in anaerobic was significantly higher than in aerobic conditions. The residue cellulose content varied in a range from 68.2% to 78.6%, while the hemicellulose content varied from 57.4% to 69.3% at day 50 after incorporation. There were no significant differences in the total nitrogen removal, cellulose, hemicellulose, and lignin contents among the microcosm set-ups. CO₂ emission increased in all the microcosm set-ups with the treatments without rice straw (CTSR, CTSB) in both aerobic and anaerobic conditions. CH₄ release in the SR-AN treatments did not differ significantly compared with the SB-AN treatments. This study confirmed that the decomposition of rice straw residues is faster in the anaerobic paddy soil condition compared to the aerobic crop rotation condition.

Ecotoxicological assessment of Zn, Cu and Ni based NPs contamination in Arenosols

Nanoparticles are increasingly used in many industrial fields because of their special properties. In this context, several questions arise related to possible negative consequences associated with nanoparticle (NPs) entrance into the ecosystem. The adsorption of NPs by soil can adversely influence its biological properties. In the present article, the influence of Cu, Zn, and Ni NPs on the biological characteristics of Arenosol is considered. Research aimed to study the effect of Cu, Zn, Ni NPs on the biological characteristics of sandy loam chernozem. Copper, Zn, and Ni NPs were added to the soil in concentrations of 100, 1,000, and 10,000 mg kg^-1. The effect of NPs on the biological properties of Arenosol was evaluated after 10-day incubation. The biological indices of the ecological condition of the soil, including the germination of radish, the length of the roots, the bacteria population, <em>Azotobacter</em> sp. count, the catalase activity, and dehydrogenases were studied. As a result of this study, it was revealed that the degree of indices changes depending on the concentration of Cu, Zn, and Ni NPs in the Arenosols. Microbiological characteristics (bacteria population, and <em>Azotobacter</em> sp. count) and phytotoxic feature (length of roots and radish germination) properties were most sensitive to contamination compared to the enzyme activity of Arenosol. Based on the soil integral index of a biological state, the strongest inhibitory effect on biological parameters of Arenosols relative to the control was exerted by Cu NPs (lower than control by 48-72%), while the greatest stability in Arenosol was found for Ni NPs (lower than control by 30-55%). The studied biological parameters allow characterizing the severity of nanoparticle exposure on Arenosols. Early diagnostics of the severity of soil contamination by NPs can be successfully used to quickly assess their impact on the soil condition and prevent possible adverse consequences.

Evaluation of Different Land Preparation Techniques for Preparing Medium Textured Soil in Rice Production under Agro-Ecological Conditions of Sheikhupura-Pakistan

Tillage is an important factor affecting different soil properties and crop yields. Tillage relates to applying forces to soil using different implements for preparation of a proper seed bed. For rice crop, land preparation is a rigorous and time consuming operation that needs special attention for preparing a puddled soil condition to transplant the weak and tender rice seedlings. A field experiment was established under agro-ecological conditions of Sheikhupura to evaluate different land preparation techniques during fall in 2017 and 2018 years. The experiment was performed at Adaptive Research Farm Sheikhupura. It was laid out in randomized complete block design (RCBD) with four different land preparation techniques including T1= Cultivator (4 times) + Planking (2 times) (Farmer’s Practice), T2=MB plough (1 time) + Disc Harrow (1 time) + Planking (2 Times), T3=MB plough (1 time) + Cultivator (2 times) + Planking (2 Times) and T4= Rotavator (1 time) + Disc Harrow (1 time) + Planking (2 Times), each treatment replicated thrice during both the years. All the other agronomic and crop husbandry operations were kept uniform throughout the growing season every year. The results revealed that preparing land with MB plough (1 time), Disc Harrow (1 time) and Planking (2 times) is the best land preparation method can increase the paddy yield 13.5-17.5% as compared to the traditional method practised by the farmers. Moreover, highest plant height (134.00 cm and 132.00 cm), number of tillers (224 and 220 m-2), number of grains per spike (130 and 116) and 1000-grain weight (23.0 and 22.0 g) respectively during Kharif-18 and Kharif-19 was also recorded in the same treatment. So, preparation of land for paddy in agro-ecological conditions of Sheikhupura using MB plough (1 time), Disc Harrow (1 time) and Planking (2 times) can significantly enhance the paddy yield.

Growth Response of Abaca (Musa textilis Nee) in Abandoned Mine Soil Amended with Oil Palm Residues

The mining industry is one of the leading sectors providing economic benefit to the community. However, mining minerals inevitably affect the ecosystem function of the land, thereby reducing ecological services provided to mankind. Soil remediation is done to restore ecological integrity while mitigating degradation processes. Thus, this study was conducted to determine the chemical properties of abandoned mine soil and to determine the effects of oil palm residues on the growth performance of abaca (Hybrid 7) grown in mined soil under nursery conditions. This study was arranged in a completely randomized design (CRD) with five treatments and four replications, namely, T1 - Mined Soil Alone, T2 - Garden Soil Alone, T3 - Mined soil + Oil Palm Sludge, T4 - Mined Soil + Oil Palm Empty Fruit Bunch (EFB) Biochar, T5 – Mined Soil + Oil Palm Vermicast. Chemical analysis of mined soil revealed extreme acidic soil condition, low organic matter, CEC, N, K, and high P content relative to soil nutrient sufficiency criteria. Mined soil contained 0.347 mg/kg Cd and 0.230 mg/kg Pb which are within the tolerable limit of 2.00 mg/ kg for Cd and 300 mg/kg (Pb), respectively. Application of oil palm residues in mined soil can significantly improve the morphology and dry matter yield performance of hybrid 7 abaca seedlings. Plants grown in mined soil amended with oil palm residues were taller, larger pseudostem girth with more and bigger functional leaves, and had a higher survival rate compared to those grown in soil derived from the abandoned mining area. Abaca plants grown with amendments had accumulated higher dry matter. Oil palm residues particularly vermicast has greater potential as soil amendment under degraded mined in Mawab, Davao de Oro.

Effects of the Predominant Pulse on the Inelastic Displacement Ratios of Pulse-Like Ground Motions Based on Wavelet Analysis

Having a predominant pulse is the main feature for pulse-like ground motions differing from others. To investigate the influence of the predominant pulse on the inelastic displacement ratios of pulse-like ground motions, the wavelet analysis method is used to extract the predominant pulse. The results indicate that the inelastic displacement ratios of the pulse-removed parts obtained by subtracting the extracted pulse from the original pulse-like ground motions are close to the results of non-pulse-like ground motions. The ratio of the energy of the extracted pulse to the energy of the original ground motion is used to represent the pulse intensity. The results indicate that the pulse period determines the locations in which the inelastic displacement ratios would have noticeable increments, and the pulse intensity determines the degree of the increments. Besides, the effects of five commonly used parameters (PGV, PGD, PGV/PGA, Arias intensity Ia, and soil condition) on the inelastic displacement ratios of pulse-like ground motions and their relations to the pulse period and the pulse intensity are studied. Finally, a new model, in which the influence of pulse intensity is considered, to predict the inelastic displacement ratios of pulse-like ground motions is proposed.

Legal regulation of information on soils

The issue of legal regulation of information support on soils is considered. The characteristics of large-scale soil studies in Ukraine, which were conducted during 1957–1961, are given. The reasons for the inconsistency of the available information on the structure and condition of the soil cover are established. It is substantiated that the data of environmental impact assessments of ecological monitoring, soil survey, cadastral documentation, etc. can be sources of ecological information. Based on the legal analysis, it was concluded that the draft law of Ukraine «On Soil Conservation and Protection of Fertility» should establish that documented information on soil condition and ongoing soil protection measures should be open, publicly available, as it is public interest, except for information that is included in the category of information with limited access. Keywords: land, soil, soil cover, land use, soil protection, soil information, soil survey, monitoring, cadastral documentation

Halo Tolerance of Biocontrol Agents against Root Rot of Mung Bean (Vigna radiata (L.) Wilczek var. radiata) Caused by Macrophomina phaseolina (Tassi) Goid in Salt Affected Soils

Root rot of mung bean [Vigna radiata (L.) Wilczek var. radiata] is major disease and claims huge yield loss if they occur in the field. The pathogen is basically soil borne and survivability may vary depends on soil condition. The fungicide chemicals are available to manage the disease; however, the biocontrol agents are nowadays available for the disease management and the microbial activity of the biocontrol agents is influenced by existing soil condition including soil pH. Hence, a study was conducted to find out the halo tolerance capacity of the biocontrol agents against root rot disease in salt affected soils under in vitro, in vivo and field condition. The root rot pathogen Macrophomina phaseolina was isolated from infected root. Efficacy of biocontrol agents against growth of M. phaseolina was assessed in vitro. The results revealed that TNAU strain of Bacillus subtilis reduced the mycelial growth of the M. phaseolina significantly when media supplemented with NaCl at 5% (1.4 cm), 7.5% (1.5 cm), 10% (1.6cm) and 12.5% (1.6 cm) and without NaCl (1.2 cm) and similar trend of reduction also expressed by BCA1 strain of B. subtilis, Pseudomonas fluorescens and Trichoderma viride under in vitro. The performance of the biocontrol agents against the pathogen is slightly reduced when media supplemented with NaCl. The reduction of mycelia weight of M.phaeolina was more in media added with TNAU strain of B.subtilis and the performance of TNAU strain of B.subtilis on reduction of mycelial weight of M.phaseolina is reduced when the broth added with NaCl at 5% (3.15g), 7.5% (3.25g), 10% (3.32g) and 12.5%(3.65g) level and which is followed by P. fluorescens, BCA 1 strain of B. subtilis and Trichoderma viride. Under pot culture conditions, the effect of talc formulated biocontrol agents and challenge inoculation with pathogen was assessed against root rot incidence. It was found that the soil application of TNAU strain of B.subtilis performed better in reducing the root rot incidence at pH of 7.0 (2.37%), 7.5 (4.50%), 8.0 (5.53%) and 8.7 (6.57%) and followed by BCA 1 of B.subtilis in all pH level. Among the biocontrol agents, TNAU strain of B.subtilis applied as seed as well as soil application expressed more population in the rhizosphere in all pH level. The biocontrol agents applied as soil application had more populations of the agents in the soil when compared to seed treatment. The halo tolerance performance of the biocontrol agents was also assessed under field condition in pH of 7.5 and 8.7 during 2019-20 and 2020-21. It was found that the minimum root rot incidence and maximum yield was observed from soil application of TNAU strain of B subtilis at 2.5 kg/ha but the effect is on par with soil application of BCA1 strain of B.subtilis at 2.5 kg/ha.

Phosphogypsum Organic, a Byproduct from Rare-Earth Metals Processing, Improves Plant and Soil

Phosphogypsum organic (PG organic) is a soil conditioner, derived from residues, water leach purification (WLP) and neutralisation underflow (NUF) from rare-earth metals processing in combination with composted organic material. There was no report available with regards to the effectiveness of this byproduct for crops improvement in a sandy soil texture. Therefore, a field trial involving a multi-crop was conducted by the addition of PG organic on a sandy texture soil for 23-month period. Guinea grass or guinea grass intercropping with teak wood trees, corn and kenaf showed an improvement in cumulative fresh yield in plot treated with PG organic either with a half- or full-fertilizer recommended rate for the respective crop as compared to control. The same trend was also observed in teak wood trees in hole planting systems and pandan coconut seedlings in the polybags. Application of PG organic in each season showed a consistently higher cumulative fresh yield or yield for certain crop types due to soil ability to maintain the soil pH buffering capacity (pH 5.8–6.0). Therefore, the application of PG organic as soil conditioner promotes plant growth and development due to the improvement of soil condition by creating suitable ecosystem for nutrients absorption by roots.