Electromagnetic Induction Measurements for Investigating Soil Salinization Caused by Saline Reclaimed Water

This paper focused on the use of electromagnetic induction measurements in order to investigate soil salinization caused by irrigation with saline reclaimed water. An experimental activity was carried out during the growing season of tomato crop in order to evaluate expected soil salinization effects caused by different saline agro-industrial wastewaters used as irrigation sources. Soil electrical conductivity, strictly related to the soil salinity, has been monitored for three months by means of Electromagnetic Induction (EMI) measurements, and evident differences in the soil response have been observed. The study highlighted two aspects that can improve soil investigation due to the utilization of geophysical tools. First, EMI data can map large areas in a short period of time with an unprecedented level of detail by overcoming practical difficulties in order to massively sample soil. At the same time, repeated measurements over time allow updating real-time soil salinity maps by using accurate correlations with soil electrical conductivity. This application points out how integrated agro-geophysical research approaches can play a strategic role in agricultural saline water management in order to prevent soil salinization risks in medium to long-term periods.

Equivalent-linear seismic ground response analysis in Palu area

The 7.5 Mw Palu earthquake on September 28, 2018, was caused by the Palu Koro fault. This earthquake produced forceful wave propagation in the soil layer and generated enormous surface damage in Balaroa, Petobo, and Jono Oge. Estimations of soil amplification at a specific location are helpful as guidance for infrastructure development. This study examined the effect of local soil in modifying the one-dimensional linear soil response in Balaroa, Petobo, and Jono Oge regions, considering the data of various sites in those regions. The soil response was observed to obtain the synthetic input motion and its effects in the time history of surface acceleration, the ratio of shear stress to effective vertical stress to spectrum response time, and the Fourier amplitude versus frequency ratio. Amplification is standard for ground acceleration, which considers the strong ground motion with the acquired frequency and duration of the content. The results showed that the peak of ground acceleration amplification factors for Balaroa, Petobo, and Jono Oge was around 1.49, 2.05, and 1.27 times, respectively. With a lack of information at the particular site, designers will use the response spectrum obtained along the soil layer to develop earthquake-resistant geotechnical structures in locations close to Palu.

Soil response to root-knot nematode management with wine vinasse in a solarised horticultural soil under glasshouse conditions

Summary The increasing interest in agroecological practices and the current consideration of agrarian soils as a sustainable resource are driving the development of new strategies to manage soil parasites and diseases. The application of organic matter from different sources to reduce plant parasites contributes to circular economy by applying by-products as soil organic amendments that reduce wastes. Wine vinasse (WV) is a by-product generated to obtain alcohol from wine by physical methods in distilleries. The aim of this study was to determine the potential of WV and its combination with animal manure (WV+M) as soil biodisinfestation products. For this, it was compared with a plastic-covered control to distinguish the biodisinfestation from solarisation effect. The crops tested consisted of a tomato-Swiss chard rotation under glasshouse conditions. Their effects on Meloidogyne incognita, soil fertility, nematode community and crop yield were assessed. The results obtained after two seasons showed a reduction of M. incognita galling in the root system of both crops. The immediate effect after the treatment application was a reduction in the abundance of nematodes and changes in the nematode-based indices that affected all plots, including the control, most likely related to the tillage effect for the treatments application and the plastic cover. Soil fertility was improved by the application of WV (NO3−, Bioav. P) and WV+M (C, Ntotal, K), which reduced herbivore nematode metabolic footprints and enhanced bacterivore footprints. Our results indicate that the combination WV+M was effective reducing M. incognita infection, and improved crop yield. Use of by-products such as WV is a helpful tool for managing horticultural soils.

Long-term response planting method on wheat under conservation agriculture

Objective: To compare different bed planting systems: narrow beds (80 cm), wide beds (100 cm), and flat soil, on the growth and yield of wheat under conservation system. Design/methodology/approach: Treatments were established on a complete block design with three replicates; also, wheat crop was grown during five seasons. Treatments were as follow: A) wide beds (furrows at 100 cm), B) narrow beds (furrows at 80 cm) and C) flat soil. Response variables were dry weight of 50 stems, weight of 1000 grains, number of spikes (m2), harvest index and yield. Also, the relationship between relative yield and cold units and degree-days were measured. Results: Flat soil reach the highest dry weight of 50 stems, whereas narrow beds had the maximum number of spikes per m2. Yield was equal between flat soil and narrow beds. No differences were found in the harvest index (HI) among the evaluated treatments. When comparing results between years, dry weight of 50 stems increased and the HI index decreased, affecting negatively the yield. A negative association was found between chill hours and yield. Findings/conclusions: Despite yield was equal between flat soil and narrow beds, reduction on yields was mainly associated with of reduction in chill hours occurring in each season.

A New Environmentally Friendly Utilization of Energy Piles into Geotechnical Engineering in Northern China

In the past 30 years, because of built-in advantages, energy saving, pollution control, and sustainability, the energy pile system has had a rapid development around the world. Many scholars did numerous researches on the parameters’ optimization, heat exchange efficiency, and structure-soil response. Also, the researches of evolutional GSHP system using high temperature in deep mine and lager collection surface of tunnel lining were learned. At present, most of researchers are discussing the geothermal collection for the heating or cooling the building, and plenteous and significant research achievements have been obtained. It is a novel attempt to apply energy pile to geotechnical engineering, and good results have been achieved in engineering practice in Northern China. The area of northern China is a typical seasonal frozen region: the high temperature in summer and the cold weather and accumulated snow in winter will result in huge challenge and resource consumption of maintaince on highway tunnel, pavement, and other geotechnical engineering facilities. In this paper, taking example of using the geothermal heat exchanger to melt snow, the novel idea of using energy piles to prevent track in summer and crack in winter of pavement, and guaranteeing the safety of frost crack on tunnel lining were discussed. Also, through simulation research, we propose a buried pipe form with good heat transfer uniformity-spiral buried pipe, which has better engineering applicability. This shows us that the application of energy pile in geotechnical engineering will provide solutions to geotechnical problems, which will have a brilliant future.

Formulation of a Basic Constitutive Model for Fine - Grained Soils Using the Hypoplastic Framework

A hypoplastic approach to constitutive modelling was developed by Kolymbas 1996 considering a non-linear tensor function in the form of strain and stress rate. However, the implicit formulation of the hypoplastic model with indirect material parameters severely limits its applicability to real-world geotechnical problems. In many cases, the numerical analysis of geotechnical problems relies on simple elastoplastic constitutive models that cannot model a wide range of soil response aspects. One promising paradigm of constitutive modelling in geotechnics is hypoplasticity, but many of the hypoplastic models belong to advanced models. In the article, we present the simple hypoplastic model as an alternative to the widely used Mohr-Coulomb elastoplastic model.

PSIII-19 Soil nutrient profile from cool-season forages fertilized with manure from steers supplemented with titrated levels of dried distillers grains

Dried distillers grains with solubles (DDGS) is commonly used as supplemental feed in cattle rations. However, the systemic effects of overfeeding DDGS, especially to potential fertilizer benefits of pass-through nitrogen, are widely unknown. Therefore, our objective was to evaluate plant and soil response to fertilization with manure from steers supplemented with titrated levels of DDGS. Manure utilized was collected from steers supplemented with DDGS (0%, 0.25%, 0.5%, and 1% BW) during a 2-yr experiment. The experimental design was a randomized complete block design with an augmented factorial treatment structure wherein benches represented blocks. The factorial was made up of manure treatment (0, 0.25, 0.5, or 1% BW DDGS, chemical fertilizer, or none) soil type (Windthorst or Purves), and plant species (none, crimson clover, or rye). Pots were sown (5 seeds/pot) and grown in a greenhouse for 35 d. Water was applied daily at 90% evapotranspiration. After harvest, soils were sifted, dried for 72 h at 55°C, then assayed for C, N, NO3-N, P, K, Ca, Mg, Na, and S. There was an interaction of manure and soil type for soil C (P < 0.01). Purves soils amended with any manure had a greater (P < 0.05) concentration of C (1.8%) than did the negative control (1.3%). From Windthorst, soil C was greatest from 1% BW DDGS manure (1.9%), and least from 0% DDGS manure (1.5%), with 0.25 and 0.5% manures and the negative control intermediate. There was an interaction of manure, soil type, and forage for soil N (P < 0.01). Manures with higher levels of supplementation had greater (P < 0.05) soil N than lower levels of supplementation or the negative control. Legumes had greater soil N than grasses. Results are interpreted to mean that moderate supplementation of steers with DDGS may yield soil nutrient benefits through nutrient deposition.

Inundation depth and duration impacts on wetland soils and vegetation : state of knowledge

The following synthesizes studies investigating plant and soil responses to increased inundation in order to support ecosystem restoration efforts related to the alteration of natural wetland hydrodynamics. Specific topics include hydrologic regimes, soil response to inundation, and implications for vegetation communities exposed to increased water depths. Results highlight the important interactions between water, soils, and vegetation that determine the trajectory and fate of wetland ecosystems, including the development of feedback loops related to marsh degradation and subsidence. This report then discusses the knowledge gaps related to implications of inundation depth, timing, and duration within an ecosystem restoration context, identifying opportunities for future research while providing source materials for practitioners developing restoration projects.

The Origin of Eight Trigrams: Explaining the Mechanism of Soil Response to Temperature Change

The Eight Trigrams has held a high position in the Eastern culture, but its origin of has been a mystery for thousands of years, thus it has not yet entered the scientific system. This research reveals the possible origin of the Eight Trigrams and the purpose of drawing the hexagrams. Research has shown that due to changes in the solar radiation there exist annual and diurnal soil temperature variable zones (STVZs). The heat conducts and interactions between the double-layer also form two different statuses of warming and cooling. In this paper the hydrometeorological factors such as temperature, relative humidity, absolute humidity and earth-air pressure were monitored or calculated in the STVZs. If the anural/diurnal STVZ is divided into three levels, and we associate soil cooling processes (Yin) with “--” and warming processes (Yang) with “—”. It is not hard to find that the distribution of soil status in soil profile at different times and locations clearly reflects the soil response to temperature change and reveals movement mechanism of earth-air and water. Furthermore, this model can be seen to be the source of the Eight Trigrams in the Yi-jing. The double-layer structure of the soil constitutes the foundation of the double trigrams. The Yin and Yang processes both form the primary driving force for phreatic water moves upward. Fu Xi invented the method of hou-qi, in which the monitoring of earth-air pressure in the closed system and applying Yin-Yang to draw Eight Trigrams and analysis of spatiotemporal status changes in the soil, which was then used to enact a calendar used as a guide to time for farming usage. The Yin-Yang and Eight Trigrams perfectly explain the response of earth-air to solar terms and mechanisms of water vertical cycle on daily/yearly timescales.