scholarly journals Variability of Soil Water Heat and Energy Transfer Under Different Cover Conditions in a Seasonally Frozen Soil Area

2020 ◽  
Vol 12 (5) ◽  
pp. 1782
Author(s):  
Fanxiang Meng ◽  
Renjie Hou ◽  
Tianxiao Li ◽  
Qiang Fu

In a seasonally frozen soil area, there is frequent energy exchange between soil and environment, which changes the hydrological cycle process, and then has a certain impact on the prediction and management of agricultural soil moisture. To reveal the effects of different modes of regulation on the energy budget of soil in a region with seasonally frozen soil, four treatments, including the regulation of bare land (BL), biochar (CS), and straw (JS), and the combined regulation of biochar and straw (CJS), were used in field experiments. The variations in the soil temperature, liquid water content, and total water content were analyzed, the energy budget of the soil was calculated, the response functions of the soil energy were determined, and the mechanism of soil energy transfer was elucidated. The results showed that, during the freezing period, the JS treatment reduced the amplitudes of the variations in the soil temperature and liquid water content and increased the water content at the soil surface. During the thawing period, the CJS treatment effectively improved the soil hydrothermal conditions. During the freezing period, the heat absorbed by the CS and JS treatments reduced the fluctuation of the soil energy budget. At a soil depth of 10 cm, the spectral entropy of a time series of the soil net energy was 0.837 under BL treatment, and the CS, JS, and CJS treatments decreased by 0.015, 0.059, and 0.045, respectively, compared to the BL treatment. During the thawing period, the CS treatment promoted energy exchange between the soil and the external environment, and the spectral entropy of a time series of the soil net energy was increased; the JS treatment had the opposite effect. The CJS treatment weakened the impact of environmental factors on the soil energy budget during the freezing period, while it enhanced the energy exchange between the soil and the environment during the thawing period. This study can provide important theoretical and technical support for the efficient utilization of soil hydrothermal resources on farmland in cold regions.

2014 ◽  
Vol 1065-1069 ◽  
pp. 783-787
Author(s):  
Jin Fang Hou ◽  
Rui Qi Zhang ◽  
Jian Yu

Research on frost heaving of high speed railway subgrade filling in seasonal frozen soil area is developed indoor. Through freezing and thawing strength and frost heaving amount test, the research analyzes factors affecting frost heaving of subgrade filling, points out that water content, fine stuff admixing amount and plasticity of fine-grained soil have relatively large influence on frost heaving, while freezing temperature and freezing and thawing cycle index have relatively small influence. Water content is main factor to have effect on frost heaving of subgrade filling. When the water content reaches to some certain value, even coarse-grained soil can produce considerable frost heaving amount. Therefore, taking effective waterproof and drainage measures is of great importance in subgrade frost heaving prevention and treatment.


2011 ◽  
Vol 52 (58) ◽  
pp. 37-43 ◽  
Author(s):  
Kunio Watanabe ◽  
Tetsuya Kito ◽  
Tomomi Wake ◽  
Masaru Sakai

AbstarctEstimating soil-water flow during ground freezing is important for understanding factors affecting spring farming, soil microbial activity below the frozen soil, and permafrost thawing behavior. In this study, we performed a column freezing experiment using three different unsaturated soils (sand, loam and silt loam) to obtain a detailed dataset of temperature, water-content and pressure-head change under freezing conditions. The liquid water content and pressure head in the three soils decreased with decreasing temperature. Three soil temperature stages were found: unfrozen, stagnating near 0˚C and frozen. The temperature and duration of the stagnation stage differed among the soil types. The changes in liquid water content and pressure head during the freezing process were highly dependent on the soil-water retention curve. Water flowed through the frozen area in silt loam and sand, but no water flux was observed in the frozen loam. The freezing soil columns tended to contain more liquid water than estimated from retention curves measured at room temperature, especially at the early stage of freezing.


Sensors ◽  
2017 ◽  
Vol 17 (3) ◽  
pp. 647 ◽  
Author(s):  
Carlos Pérez Díaz ◽  
Jonathan Muñoz ◽  
Tarendra Lakhankar ◽  
Reza Khanbilvardi ◽  
Peter Romanov

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Changjiang Li ◽  
Shuo Li

AbstractThe well-irrigated planting strategy (WI) consumes a large amount of energy and exacerbates greenhouse gas emissions, endangering the sustainable agricultural production. This 2-year work aims to estimate the economic benefit, energy budget and carbon footprint of a wheat–maize double cropping system under conventional rain-fed flat planting (irrigation once a year, control), ridge–furrows with plastic film mulching on the ridge (irrigation once a year, RP), and the WI in dry semi-humid areas of China. Significantly higher wheat and maize yields and net returns were achieved under RP than those under the control, while a visible reduction was found for wheat yields when compared with the WI. The ratio of benefit: cost under RP was also higher by 10.5% than that under the control in the first rotation cycle, but did not differ with those under WI. The net energy output and carbon output followed the same trends with net returns, but the RP had the largest energy use efficiency, energy productivity carbon efficiency and carbon sustainability among treatments. Therefore, the RP was an effective substitution for well–irrigated planting strategy for achieving sustained agricultural development in dry semi-humid areas.


1981 ◽  
Vol 27 (95) ◽  
pp. 175-178 ◽  
Author(s):  
E. M. Morris

Abstract Field trials show that the liquid-water content of snow can be determined simply and cheaply by a version of Bader’s solution method.


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