Straw Checkerboard Barriers Improve Soil Characteristic and Growth Performance of Winter Cover Crops and Protect Sloping Land

Aims Finding how straw checkerboard barrier technology, as a sustainable and environment-friendly method, may affect soil chemical properties and water status despite wind erosion control directed us to evaluate this technique as a vital component of management plans in sloping lands of semi-arid areas. We were interested to know if it could support the soil capabilities to grow pilot plants and recover some ecological services via alleviate drought stress or amendment of soil attributes.Methods In order to study soil characteristic and growth performance of winter cover crops, an experiment was carried out in 2018. Checkerboards were setup in a 1×1 m pattern with rice residues. Seeds of sainfoin (Onobrychis sativa), rye (Secale montanum) and tall wheatgrass (Agropyron sp) were sown at the checkerboards and bare ground as the control. Detailed analyses include growth characteristics, physiological attributes i.e. photosynthetic pigment contents, proline and malondialdehyde contents and relative water contents of mentioned crops and the related soil properties during the growing season were carried out in borders and centers of the straw checkerboards and bare ground.Results Soil covered with straw checkerboard barriers was the most effective for improving vegetation growth and establishing taller plants with higher biomass. Based on the physiological analyses, the rye grown in straw checkerboard plots coped well with dry conditions. Higher proline content and more efficient osmotic adjustment indicates improvements of soil water retention status, which may alleviate drought stress damages and improve cover crop performance in straw checkerboard plots. Photosynthetic pigments also showed higher contents in checkerboards for rye. Soil organic matter, total nitrogen, available phosphorus, potassium and water storage increased in checkerboards too, however, such effects vary with the crop type. Conclusions straw checkerboards could be deemed as an effective management strategy in semi-arid areas, as an important method for conserving natural resources and sustaining productivity.

Study on landslide susceptibility mapping based on rock–soil characteristic factors

This study introduces four rock–soil characteristics factors, that is, Lithology, Rock Structure, Rock Infiltration, and Rock Weathering, which based on the properties of rock formations, to predict Landslide Susceptibility Mapping (LSM) in Three Gorges Reservoir Area from Zigui to Badong. Logistic regression, artificial neural network, support vector machine is used in LSM modeling. The study consists of three main steps. In the first step, these four factors are combined with the 11 basic factors to form different factor combinations. The second step randomly selects training (70% of the total) and validation (30%) datasets out of grid cells corresponding to landslide and non-landslide locations in the study area. The final step constructs the LSM models to obtain different landslide susceptibility index maps and landslide susceptibility zoning maps. The specific category precision, receiver operating characteristic curve, and 5 other statistical evaluation methods are used for quantitative evaluations. The evaluation results show that, in most cases, the result based on Rock Structure are better than the result obtained by traditional method based on Lithology, have the best performance. To further study the influence of rock–soil characteristic factors on the LSM, these four factors are divided into “Intrinsic attribute factors” and “External participation factors” in accordance with the participation of external factors, to generate the LSMs. The evaluation results show that the result based on Intrinsic attribute factors are better than the result based on External participation factors, indicating the significance of Intrinsic attribute factors in LSM. The method proposed in this study can effectively improve the scientificity, accuracy, and validity of LSM.

Extent and distribution of surface soil acidity in the rainfed areas of Ethiopia

The soil acidity level is a key soil characteristic that determines soil nutrient availability, soil microbial activities and crop growth. However, studies on distribution and extent of soil acidity in Ethiopia are not available. This study was carried out to predict the extent and severity of soil acidity. The study used 88,265 soil pH samples collected from soil laboratories and 21,439 samples compiled from studies. Rainfall, altitude, slope gradient, soil, and land cover were considered to generate spatial autocorrelation and integrated into geospatial analysis to predict the soil pH. The performance of the kriging model was found to be satisfactory with a standard error of 0.77, RMSE of 0.51, and R2 of 0.74. The model estimates showed that 47% and 30.2% of the country’s total area and rainfed areas were acidic (pH<6.5), respectively. Out of the total area of the country, 3.7% is found to be extremely to strongly acidic (pH<5.5), 20.7% is moderately acidic (5.6

Reasons for violation of geotechnology during the building of tunnels and subways

Due to its specificity and increased complexity, the building of underground transport interchanges and subways is often accompanied by the occurrence of emergencies. Each accident requires careful analysis for further consideration of abnormal situations during design and building. Goal. The goal is to find causes of emergencies during the building of tunnels and subways for studying them and gaining experience in preventing such situations in the future. Methodology. The experience in the building of underground structures shows that abnormal emergencies arise because of the influence of unfavorable natural factors, technical malfunctions and the human factor. The analysis of errors in tunneling showed that the violation of geotechnologies is a serious problem, and the occurrence of accidents is influenced by a set of causes that are difficult to predict due to their close interconnection. Results. The use of geotechnologies in underground construction is extremely necessary. Only by establishing cooperation between geotechnicians and design engineers, emergencies can be prevented. Originality. In multiphase systems, soil characteristic is accompanied by its stratification into separate phases, one of which is decompaction. This changes the magnitude of the loads that are transferred to the foundation pit fencing or to the temporary fastening of the tunnel. As a result, an inadequate soil model that is very difficult to assess over time arises. Practical value. During the building of tunnels and subways, it is necessary to clearly identify the cause of each phenomenon that has led to the accident, in order to exclude cost and time overspendings.

Straw Checkerboard Barriers Improve Soil Characteristic and Growth Performance of Winter Cover Crops and Protect Sloping Land

Aims Straw checkerboard barrier technology, as a sustainable and environment-friendly method, is intended for erosion control, plant recovery at endangered areas. Finding how soil chemical properties and water status alters and how pilot cover plants respond are vital for extra management actions. Methods In order to study soil characteristic and growth performance of winter cover crops, an experiment was carried out in 2018. Checkerboards were setup in a 1×1 m pattern with rice residues. Seeds of Onobrychis sativa, Secale montanum and Agropyron sp were sown at the checkerboards and bare ground as the control. Detailed analyses were carried out on the physiological responses and the related soil properties during the growing season in borders and centers of the straw checkerboards and bare ground. Results Soil covered with straw checkerboard barriers was more effective for improving vegetation growth, established taller plants with higher biomass. Based on the physiological analyses, the rye grown in a straw checkerboard coped well with dry conditions. Higher proline content and more efficient osmotic adjustment indicate improvements of soil water retention status, which may alleviate drought stress damages and improve cover crop performance in straw checkerboard plots. Photosynthetic pigments also showed higher contents in these conditions for rye. Soil organic matter, total nitrogen, available phosphorus and potassium and water storage increased in checkerboards too; however, such effects vary with the crop type. Conclusions This technique could be deemed as an effective management strategy in semi-arid areas and an important method for conserving natural resources and sustaining productivity.

Soil characteristic and shallot growth with gypsum and zeolite amendments in irrigated saline Alfisol and Inceptisol

Salinity of soil and irrigation is a factor that may cause a decrease in shallot productivity, so it requires efforts with amendments. This research aimed to determine the effect of gypsum and zeolite amendments on soil and shallot growth with saline irrigation. A pot experiment was conducted in the field using a completely randomized design with three factors. The first factor was two soil types (Alfisol and Inceptisol); the second factor was three shallot cultivars (Brebes, Purbalingga, and Pemalang); and the third factor was two types of soil amendments. The results showed that gypsum and zeolite reduced pH, sodium adsorption ratio (SAR), electric conductivity paste (ECp) and Na of the soils studied. Gypsum and zeolite increased the uptake of N, P and K by shallot plants. The increase of N uptake by applying gypsum on Inceptisol was more effective to Brebes and Purbalingga cultivars than Pemalang cultivar. Gypsum increased the diameter and number of bulbs in Inceptisol. Zeolite and gypsum increased bulb weight of Purbalingga cultivar in Alfisol.

Hygrophilous flora different-type lakes of the Kasmalinsky river-lake system (Ob-Irtysh Interfluve)

In the paper results of hygrophilous flora for five lakes of the Kasmalinsky river-lake system are presented.An analysis of taxonomic and ecologic structure of lakes flora was performed. It was shown, that the water salinity andbottom soil characteristic has effect on species diversity. Three types of lake overgrowing are demonstrated: massivethickets, border and floating.

ANALISI PENURUNAN FONDASI TIANG RAKIT TERHADAP PENGARUH LIKUIFAKSI DI SULAWESI

Liquefaction is one of the most dangerous effect of earthquake. When earthquake happens, the soil characteristic will change from solid to liquid state because of the dynamic cyclic load. Buildings that sits on such soil will totally fail because of the soil loss of bearing capacity. So, detailed analysis and evaluation of the potential of liquefaction when earthquake occurs is needed, such as CSR and CRR, Chinese Criteria, Tsuchida, Bray & Sancio and Seed et al. The result of the analyses will be compared to each method to other. The result of the analysis will show whether liquefaction happen or not in every layer of the analysed soil. Steps that that are usually made by the geotechnical engineer expert is that the soil need to be improved beforehand. But in this study. Piled-raft foundation which is combination of piled and raft foundation is used for settlement analysis. The result of the analysis will show the settlement of the foundation before and after its affected by liquefaction.Likuifaksi merupakan salah satu peristiwa yang sangat bahaya yang ditimbulkan oleh bencana bumi. pada saat gempa bumi terjadi, sifat tanah akan berubah dari solid menjadi liquid akibat beban siklik yang terjadi. Bangunan yang menempati tanah yang mengalami likuifaksi akan langsung gagal total karena tanah mengalami kehilangan daya dukung. Untuk itu, diperlukan metode-metode yang rinci untuk menganalisis dan mengevaluasi potensi terjadinya likuifaksi saat terjadi gempa, yaitu analisis potensi likuifaksi yang dapat berupa analisis CSR dan CRR, Chinese Criteria, Tsuchida, Bray & Sancio dan Seed et al. Hasil analisis potensi likuifkasi tersebut akan dibandingkan satu metode dengan yang lainnya. Hasil analisis menunjukan potensi terjadinya likuifaksi pada tiap lapisan tanah yang akan ditampilkan dalam bentuk grafik maupun tabel. Fondasi tiang rakit yang merupakan gabungan antara fondasi tiang dan rakit digunakan untuk analisis penurunan fondasi pada skripsi ini. Hasil analisis akan menunjukan penurunan fondasi sebelum dan setelah likuifaksi terjadi yang akan ditampilkan dalam bentuk tabel.