scholarly journals Plant available moisture content in soils of Belarus under the current conditions

2014 ◽  
Vol 14 (4) ◽  
pp. 195-202
Author(s):  
Aleksandr A. Volchak ◽  
Ivan Kirvel

Abstract One of the soil fertility parameters is water content in the root zone; therefore the estimation of the transformation of water resources in mineral soils of Belarus is rather relevant. The analysis of plant available moisture content (PAMC) was conducted for the topsoil layer of 50 cm thickness for the period of monitoring from 1960 until 2001. Results were submitted as maps on the basis of which the spatial and time variability of the PAMC was estimated. The quantitative estimation of changes in the plant available moisture content was carried out with the help of gradients of linear trends

Jurnal Kimia ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 22
Author(s):  
N. P. S. E. Cahyani ◽  
J. Susiarni ◽  
K. C.S. Dewi ◽  
N. L.P. Melyandari ◽  
K. W.A. Putra ◽  
...  

Kepuh (Sterculia foetida L) is a type of kapok plant that has been scientifically proven to have activity as an anti-inflammatory and analgesic. 70% ethanol extract of stem stem is obtained by maceration using 70% ethanol. Examination of the characteristics of 70% ethanol extract of kepuh stem included organoleptic, of moisture content and determination of residual solvent content. Phytochemical screening of 70% ethanol extract of kepuh bark includes: alkaloid, flavonoid, saponin, tannin , polyphenol, and examination of glycosides. The results of the examination of the characteristics of 70% ethanol extract of kepuh stem obtained water content of 8.66 ± 0.748%, the residual content of the solvent had a 0 (zero) ethanol level. The results of phytochemical screening showed 70% ethanol extract of stem stem containing steroid compounds, triterpenoids, flavonoids, saponins, tannins and polyphenols. The identification using UV-Vis spectrophotometry produced ? 212, the absorbance was 1.8601 and ? 284, the absorbance was 0.42186.


2020 ◽  
Vol 857 ◽  
pp. 203-211
Author(s):  
Majid Hamed ◽  
Waleed S. Sidik ◽  
Hanifi Canakci ◽  
Fatih Celik ◽  
Romel N. Georgees

This study was undertaken to investigate some specific problems that limit a safe design and construction of structures on problematic soils. An experimental study was carried out to examine the influence of loading rate and moisture content on shear strength of organic soil. Influece of moisture content on interface friction between organic soil and structural materials was also attempted. A commonly used soil in Iraq was prepared at varying moisture contents of 39%, 57% and 75%. The experimental results showed that the increase in water content will decrease the shear stress and the internal friction angle. An increase of the shearing rate was found to decrease the shear stress and internal friction angle for all percetanges of water contents. Further, direct shear tests were carried out to detect the interface shear stress behavior between organic soil and structural materials. The results revealed that the increase in water content was shown to have significant negetavie effects on the interface internal friction and angle shear strength.


Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 425 ◽  
Author(s):  
Fairouz Slama ◽  
Nessrine Zemni ◽  
Fethi Bouksila ◽  
Roberto De Mascellis ◽  
Rachida Bouhlila

Water scarcity and quality degradation represent real threats to economic, social, and environmental development of arid and semi-arid regions. Drip irrigation associated to Deficit Irrigation (DI) has been investigated as a water saving technique. Yet its environmental impacts on soil and groundwater need to be gone into in depth especially when using brackish irrigation water. Soil water content and salinity were monitored in a fully drip irrigated potato plot with brackish water (4.45 dSm−1) in semi-arid Tunisia. The HYDRUS-1D model was used to investigate the effects of different irrigation regimes (deficit irrigation (T1R, 70% ETc), full irrigation (T2R, 100% ETc), and farmer’s schedule (T3R, 237% ETc) on root water uptake, root zone salinity, and solute return flows to groundwater. The simulated values of soil water content (θ) and electrical conductivity of soil solution (ECsw) were in good agreement with the observation values, as indicated by mean RMSE values (≤0.008 m3·m−3, and ≤0.28 dSm−1 for soil water content and ECsw respectively). The results of the different simulation treatments showed that relative yield accounted for 54%, 70%, and 85.5% of the potential maximal value when both water and solute stress were considered for deficit, full. and farmer’s irrigation, respectively. Root zone salinity was the lowest and root water uptake was the same with and without solute stress for the treatment corresponding to the farmer’s irrigation schedule (273% ETc). Solute return flows reaching the groundwater were the highest for T3R after two subsequent rainfall seasons. Beyond the water efficiency of DI with brackish water, long term studies need to focus on its impact on soil and groundwater salinization risks under changing climate conditions.


1975 ◽  
Vol 6 (3) ◽  
pp. 170-188 ◽  
Author(s):  
K. J. KRISTENSEN ◽  
S. E. JENSEN

A model for calculating the daily actual evapotranspiration based on the potential one is presented. The potential evapotranspiration is reduced according to vegetation density, water content in the root zone, and the rainfall distribution. The model is tested by comparing measured (EAm) and calculated (EAc) evapotranspirations from barley, fodder sugar beets, and grass over a four year period. The measured and calculated values agree within 10 %. The model also yields information on soil water content and runoff from the root zone.


1941 ◽  
Vol 31 (4) ◽  
pp. 466-478 ◽  
Author(s):  
T. N. Jewitt

1. The degree of dispersion on shaking of the heavy clay Gezira soil has been studied in relation to its initial moisture content when it is added to the water. A minimum dispersibility was found at about 7% initial moisture content. Such behaviour is different from that found with certain English soils by Puri & Keen.2. Spontaneous dispersion was studied using the same soil, and by this method it was found that the dispersion decreases with increasing moisture content over a range of zero to 9% moisture.3. This relation between dispersion and water content is discussed in relation to possible effects in the field of practice. Attention is drawn to possible seasonal and daily differences in the effect of rainfall.


1997 ◽  
Vol 24 (1) ◽  
pp. 19-24 ◽  
Author(s):  
P. J. Sexton ◽  
J. M. Bennett ◽  
K. J. Boote

Abstract Peanut (Arachis hypogaea L.) fruit growth is sensitive to surface soil (0-5 cm) conditions due to its subterranean fruiting habit. This study was conducted to determine the effect of soil water content in the pegging zone (0-5 cm) on peanut pod growth rate and development. A pegging-pan-root-tube apparatus was used to separately control soil water content in the pegging and root zone for greenhouse trials. A field study also was conducted using portable rainout shelters to create a soil water deficit. Pod phenology, pod and seed growth rates, and final pod and seed dry weights were determined. In greenhouse studies, dry pegging zone soil delayed pod and seed development. In the field, soil water deficits in the pegging and root zone decreased pod and seed growth rates by approximately 30% and decreased weight per seed from 563 to 428 mg. Pegs initiating growth during drought stress demonstrated an ability to suspend development during the period of soil water deficit and to re-initiate pod development after the drought stress was relieved.


2021 ◽  
Author(s):  
Xizhi Lv ◽  
Shaopeng Li ◽  
Yongxin Ni ◽  
Qiufen Zhang ◽  
Li Ma

<p>In the past 60 years, climate changes and underlying surface of the watershed have affected the structure and characteristics of water resources to a different degree It is of great significance to investigate main drivers of streamflow change for development, utilization and planning management of water resources in river basins. In this study, the Huangshui Basin, a typical tributary of the upper Yellow River, is used as the research area. Based on the Budyko hypothesis, streamflow and meteorological data from 1958-2017 are used to quantitatively assess the relative contributions of changes in climate and watershed characteristic to streamflow change in research area. The results show that: the streamflow of Huangshui Basin shows an insignificant decreasing trend; the sensitivity coefficients of streamflow to precipitation, potential evapotranspiration and watershed characteristic parameter are 0.5502, -0.1055, and 183.2007, respectively. That is, an increase in precipitation by 1 unit will induce an increase of 0.5502 units in streamflow, and an increase in potential evapotranspiration by 1 unit will induce a decrease of 0.1055 units in streamflow, and an increase in the watershed characteristic parameter by 1 unit will induce a decrease of 183.2007 units in streamflow. Compared with the reference period (1958-1993), the streamflow decreased by 20.48mm (13.59%) during the change period (1994-2017), which can be attribution to watershed characteristic changes (accounting for 73.64%) and climate change (accounting for 24.48%). Watershed characteristic changes exert a dominant influence upon the reduction of streamflow in the Huangshui Basin.</p>


2016 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Febby J Polnaya ◽  
Rachel Breemer

The purpose of this research was to characterize chemical and sensory properties (color, texture, taste and liking) of starch-based sago, cassava, sweet potato and cocoyam cookies. Analysis of cookies include moisture content, ash, fat, protein, crude fiber and sensory analysis including color, texture, taste and likeness). The proximate composition indicated that the water content of cookies varied between 1.48 to 2.05%, ash content of 0.65 to 0.72%, 19.23 to 21.76% of fat, crude fiber from 0.41 to 0.71% and 1.33 to 2.42% of total protein. Based on organoleptic tests, the color of cookies was yellow to brownish-yellow, with crispy texture, the taste was sweet and were mostly preferred.


Author(s):  
Yanwei Fan ◽  
Liangjun Ma ◽  
Hujun Wei ◽  
Pengcheng Zhu

Abstract Vertical line source irrigation (VLSI) is an underground irrigation method suitable for deep-rooted plants. Understanding the characteristics of the soil wetting body of the VLSI was the key to designing this irrigation system. On the basis of experimental verification of the reliability of the HYDRUS simulation results of VLSI under the conditions of soil texture (ST), initial water content (θi), line source buried depth (B), line source diameter (D) and line source length (L), numerical studies of the migration law of the wetting front of VLSI and the distribution characteristics of soil moisture were performed. The wetting front migration (WFM) was mainly influenced by ST, θi, D and L (P < 0.05), while B had little effect on WFM (P > 0.05). The shape of the soil wetting body changed little under different influencing factors. The water content contour was approximately ‘ellipsoidal’ around the line source. The soil moisture near the line source was close to the saturated moisture content. The moisture content around the line source gradually decreased outward, and the contour lines gradually became dense. According to the simulation results, a prediction model of multiple factors influencing the migration process of the VLSI wetting front was established. The predicted value was in good agreement with the measured value. The results of this research could provide a theoretical basis for further optimizing the combination of VLSI and irrigation elements.


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