Estimation of soil moisture using confined compression curve parameters

Geoderma ◽  
2018 ◽  
Vol 318 ◽  
pp. 64-77 ◽  
Author(s):  
Hossein Bayat ◽  
Eisa Ebrahimi ◽  
Mahboubeh Fallah
2019 ◽  
Vol 2019 ◽  
pp. 1-23
Author(s):  
Haicheng She ◽  
Zaiqiang Hu ◽  
Zhan Qu ◽  
Hongru Li ◽  
Hu Guo ◽  
...  

Undisturbed loess is affected by external environmental disturbances, such as wetting and freeze-thaw cycles, which cause microstructural changes that have an important impact on the structural strength of the loess. These changes in turn affect the stability of structures such as embankments, slopes, and guards. This article takes the Q3 undisturbed loess in Lintong District, Xi’an, as an example. The effects of wetting and freeze-thaw cycles on the loess expansion ratio and pore structure were studied by wetting tests, freeze-thaw cycle tests, and scanning electron microscopy (SEM). The changes in the compression index and compression modulus were studied by a confined compression test. The loess e-lgp compression curve was obtained according to the confined compression test, and the newly defined concepts of the loess structural strength, residual structural strength, and structural strength damage variable, in addition to the e-lgp compression curve, were combined with the experimental data to calculate the damage value generated by the disturbance during the sampling and preparation of loess. The deterioration of the structural strength and damage variable of loess was analyzed. Based on the microscopic statistical damage theory and Weibull distribution, the model used the volume expansion ratio as a variable to establish a statistical damage model under wetting and freeze-thaw cycles. Finally, on the basis of the test, the model parameters were determined. The models were verified by taking loess from a foundation pit in the northern suburbs of Xi’an and were in good agreement with the results of the test. Ultimately, the models have good practicability and can provide guidance for engineering design and construction.


2019 ◽  
Vol 5 (1) ◽  
pp. 97-106
Author(s):  
Rudi Budi Agung ◽  
Muhammad Nur ◽  
Didi Sukayadi

The Indonesian country which is famous for its tropical climate has now experienced a shift in two seasons (dry season and rainy season). This has an impact on cropping and harvesting systems among farmers. In large scale this is very influential considering that farmers in Indonesia are stilldependent on rainfall which results in soil moisture. Some types of plants that are very dependent on soil moisture will greatly require rainfall or water for growth and development. Through this research, researchers tried to make a prototype application for watering plants using ATMEGA328 microcontroller based soil moisture sensor. Development of application systems using the prototype method as a simple method which is the first step and can be developed again for large scale. The working principle of this prototype is simply that when soil moisture reaches a certainthreshold (above 56%) then the system will work by activating the watering system, if it is below 56% the system does not work or in other words soil moisture is considered sufficient for certain plant needs.


SIGMA TEKNIKA ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 81
Author(s):  
Muhammad Irsyam

ABSTRAK           Faktor yang menentukan kegagalan pertumbuhan suatu tanaman hampir dipengaruhi oleh teknik atau cara penyiraman tanaman yang salah. Hal ini disebabkan oleh teknik penyiraman yang dilakukan secara manual sehingga tidak semua tanaman mendapatkan asupan air yang merata untuk menghidari tanaman menjadi layu. Faktor lain yang menyebabkan kegagalan pertumbuhan tanaman adalah kelembaban tanah.          Oleh karena itu, untuk mengurangi permasalahan tersebut dirancanglah “Sistem Otomasi Penyiraman Tanaman Berbasis Telegram”. Adapun sistem ini meliputi penyiraman tanaman secara otomatis berdasarkan kadar kelembaban tanah dengan sistem pemberitahuan atau notifikasi yang akan dikirimkan kepada petani dengan menggunakan aplikasi smart phone Telegram.          Sistem ini telah mampu mengontrol penyiraman sesuai dengan kondisi yang diinginkan. Dengan adanya sistem otomasi penyiraman tanaman berbasis telegram maka dapat meningkatkan efesiensi dan efektivitas petani sehingga kualitas tanaman dapat terjaga dengan baik.Kata kunci -- Penyiraman Tanaman, Penyiraman Secara Otomatis, Telegram.ABSTRACT                Factors that determine the failure of a plant's growth of almost are influenced by incorrect cropping techniques or methods. This is caused by the technique of watering is done manually so that not all plants get a uniform water intake to avoid crops withered. Another factor that causes plant growth failure is soil moisture.          Therefore, to reduce the problem was designed "Telegram Based Water Planting Automation System". The system includes automatic watering of plants based on moisture level of the soil with a notification or notification system that will be sent to farmers using Telegram smart phone applications.          This system has been able to control the watering according to the desired conditions. With the telegraph-based plant watering plant automation system can improve the efficiency and effectiveness of farmers so that the quality of the plant can be maintained properly. Keywords -- Watering Plants, Watering Automatically, Telegram.  


Author(s):  
N.A. Thomson

In a four year grazing trial with dairy cows the application of 5000 kg lime/ ha (applied in two applications of 2500 kg/ha in winter of the first two years) significantly increased annual pasture production in two of the four years and dairy production in one year. In three of the four years lime significantly increased pasture growth over summer/autumn with concurrent increases in milk production. In the last year of the trial lime had little effect on pasture growth but a relatively large increase in milkfat production resulted. A higher incidence of grass staggers was recorded on the limed farmlets in spring for each of the four years. In the second spring immediately following the second application of lime significant depressions in both pasture and plasma magnesium levels were recorded. By the third spring differences in plasma magnesium levels were negligible but small depressions in herbage magnesium resulting from lime continued to the end of the trial. Lime significantly raised soil pH, Ca and Mg levels but had no effect on either soil K or P. As pH levels of the unlimed paddocks were low (5.2-5.4) in each autumn and soil moisture levels were increased by liming, these factors may suggest possible causes for the seasonality of the pasture response to lime


2016 ◽  
Vol 27 (3-4) ◽  
pp. 55-69
Author(s):  
M. A. Listopadsky

With gradient analysis investigated the role of soil moisture in the formation of the modern population of birds in the reserve forest plantations. Soil moisture was divided into seven grades. For this purpose used grass cover and the coefficient of local moistening. His proposed PhD L. P. Travleev. This method allows knowing the degree of influence of soil moisture at the birds. We analyzed birds species composition, population, placement in space and power of influence factors (soil moisture). Investigations were carried out on the territory of the Biosphere Reserve «Askania Nova». We studied the birds which live in the reserve at the end of the summer, autumn and winter. This happened from 2006 to 2013 years. Specially was studied as permanently specific form of birds is found in a particular humidity. The degree of coupling was studied using the amount of information that transmits to the local bird humidification. For 68 species of birds are the options of the population density, coefficient koligatsii and data communication with the seven variants of soil moisture. For all kinds of set information «price» of each option dampening that contributes to the formation of a particular community of birds. Thus, the defined contribution to the formation of soil moisture forest bird communities. Species representation and density gradient within the test moisture is not in direct linear relationship from moisture and ranges from 11 (very coldly) to 50 species (moist soil). The density of the community varies from 0,5 birds / hectare (very dry) to 269 birds / hectare (fresh soil). The strongest link between the information and the formation of moisture gradient structure avifauna is typical in a fresh soil – bird on the edge, and wet – forest representatives. These types of humidification function is performed starting in the formation of two major blocks dendrophilous community. The steppe birds give way to forest representatives when the soil slightly moist. The main conclusion of our study includes the following: than wetter the soil the more species of birds lives in the forest; some graduation humidity are the most important for separate species of birds; it is very important for birds, there are places where one can drink water. Further invasive alien species can occur where the soil is moist. Forest with dry soil is already fully occupied by birds.


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