scholarly journals Changes in maximum water holding capacity of chernozem soil caused by soil compaction

2021 ◽  
Vol 262 ◽  
pp. 03003
Author(s):  
Yuriy Bekhovykh ◽  
Larisa Bekhovykh ◽  
Aleksey Lyoevin ◽  
Evgeniy Sizov

The goal of the studies presented in the work is to estimate the changes in the maximum water holding capacity of the soil caused by soil compaction. The object of the research is a loam type of chernozem soil. The research shows that the maximum water holding capacity is a function of the soil density change and indirectly depends on the action of soil compaction factors, including external pressure level, the number of impacts on soil cover, as well as on soil moisture. Soil moisture is indicated as the most important factor in changing the maximum water holding capacity caused by soil compaction. The decrease in the maximum water holding capacity caused by soil compaction is more obvious with an increase in soil moisture, both in the research of the number of impacts and external pressure influence on this indicator. The results of the work show that the change in the maximum water holding capacity caused by a compacting action significantly depends on the initial value of the soil addition density.

2021 ◽  
Author(s):  
Jianli Zhang ◽  
Ting Zhang ◽  
Lihua Pu ◽  
Lingbin Yan ◽  
Guojun Cai ◽  
...  

Abstract Taking the litter layer of three typical plant communities (broad-leaved forest, coniferous forest, and shrubs) as the research object, this study analyzed the hydrological function characteristics of the litter layers of different typical plant communities using the indoor immersion method in order to reveal the effects of the traits of the litter layer on the hydrological functions of typical plant communities in the core area. The results showed that: (1) the litter reserve change trend decreased in order as follows: broad-leaved forest (13.31 ± 1.54 t/hm2) > shrubs (12.62 ± 2.34 t/hm2) > coniferous forest (11.36 ± 1.43 t/hm2). The coniferous forest and shrub litter reserves increased significantly with the increase of decomposition degree (F = 19.36, P < 0.01; and F = 9.19, P < 0.01, respectively), while the broad-leaved forest litter reserves decreased first and then increased significantly with the increase of decomposition degree (F = 25.70, P < 0.01); (2) the litter natural moisture content change trends were as follows: shrubs (34.09 ± 4.31 t/hm2) > broad-leaved forest (31.32 ± 1.76 t/hm2) > coniferous forest (29.48 ± 7.02 t/hm2). The change trends of the maximum water-holding capacity, maximum interception amount, maximum interception rate, effective interception amount, and effective interception rate were in descending order as follows: broad-leaved forest > shrubs > coniferous forest. The maximum water-holding capacity, maximum interception amount, and effective interception amount of litter rose with the increase of decomposition degree. The broad-leaved forest community litter layer had the strongest rainfall interception function and the best hydrological service functions. The interception function was stronger with the increase of the decomposition degree of the litter layer; (3) the water-holding and water-releasing capacity variation of the litter layers manifested as reversed “J” features for the three typical plant communities. The water-holding capacity of different plant community litter layers (Qct) was significantly positively correlated with time (t) (P < 0.01), and the equation was Qct = b + alnt, whereas the water-releasing capacity of different plant community litter layers (Qst) was significantly positively correlated with time (t) (P < 0.01), and the equation was Qst = a t b; and (4) the water absorption and release rates of the litter layers had four periods. The water absorption rate (v) was significantly negatively correlated with time (t) (P < 0.01), and the equation was v = a t− b, while the water release rate was the same. The water absorption and release rates differed by one order of magnitude in the first 5 min, exhibiting the greatest regulation and storage function, while the rate differed by only 2.1–4.5 times during the last three periods. This shows that the litter layer has the strongest rainfall regulation and storage function for only a short period of time before declining.


Geoderma ◽  
2019 ◽  
Vol 347 ◽  
pp. 194-202 ◽  
Author(s):  
Frank G.A. Verheijen ◽  
Anna Zhuravel ◽  
Flávio C. Silva ◽  
António Amaro ◽  
Meni Ben-Hur ◽  
...  

1974 ◽  
Vol 5 (3) ◽  
pp. 166-172 ◽  
Author(s):  
BENGT ROGNERUD ◽  
KNUT VÅRUM

This article describes an investigation of irrigation and water use in an area with wooden shelter belts. Soil moisture was measured using a neutron moisture probe and tensiometers. The soil is deep and the water holding capacity is very high. Values of actual evapotranspiration on irrigated and non-irrigated plots are presented.


2018 ◽  
Vol 34 (6) ◽  
pp. 939-952
Author(s):  
Suresh Niraula ◽  
Shafiqur Rahman ◽  
Amitava Chatterjee

Abstract. Greenhouse gas (GHG) [nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4)] emission and ammonia (NH3) volatilization from organic and commercial fertilizers are likely related to soil moisture levels. Effect of soil moisture [(30%, 60%, and 90% water-holding capacity (WHC)] on emissions from urea and manure treated (215 kg ha-1) Fargo-Ryan silty clay soil was studied under laboratory conditions. Soils (250 g) amended with solid beef manure (SM), straw-bedded solid beef manure (BM), urea (UR), and control (CT) were incubated for 28 days at 22±1°C, to determine GHGs (N2O, CO2, and CH4) emission and NH3 volatilization loss. The cumulative emission of N2O-N, CO2-C, and CH4-C ranged from 27 to 4402 µg N2O-N kg-1, 272 to 2030 mg CO2-C kg-1, and 10.1 to 1389 µg CH4-C kg-1 soil, respectively. The daily fluxes and cumulative emissions of N2O and CO2 generally followed the decreasing order of 30% &lt; 90% &lt; 60% of WHC. At 60% WHC, 1.01% of the total applied N was lost as N2O from urea treated soil. Carbon dioxide emission from manure treated soil (SM and BM) was up to two times the emission from UR treated soils. The Fargo clay soils showed higher CH4 emission at 90% WHC level. The cumulative NH3 volatilization loss from soil ranged from 29.4 to 1250.5 µg NH3-N kg-1, with the highest loss from UR amended soils at 30% WHC. These results suggest that gaseous emissions from manure and urea application under laboratory study are influenced by moisture levels of Fargo-Ryan silty clay soil. Keywords: Beef manure, Greenhouse gas, Soil water, Urea, Water holding capacity.


1984 ◽  
Vol 64 (4) ◽  
pp. 667-680 ◽  
Author(s):  
R. DE JONG ◽  
J. A. SHIELDS ◽  
W. K. SLY

Long-term mean soil water reserves for a spring wheat-fallow rotation in the southern half of Saskatchewan were calculated using the Versatile Soil Moisture Budget. Four different available water-holding capacity classes and climatic data from 53 stations were used as input to the model. Soil water reserve data for the following times, seeding on 1 May in the crop year, at heading on 30 June, and on 1 May in the fallow year, were mapped. These were then combined with an available water-holding capacity map to portray in a single map the combined droughtiness due to climatic and soil attributes. Estimated soil water reserves compared well with measured data from one location in the Brown soil zone. The temporal and spatial changes in water reserves are discussed and related to summerfallowing. The maps provide information for use in making potential grain yield estimates. Key words: Soil water, wheat-fallow rotation, generalized soil areas, Saskatchewan, Versatile soil moisture budget


Author(s):  
Y.V Bekhovykh ◽  

The research goal was to study effect of soil compaction on potential moisture content. The object of study was leached chernozem of Priobskoye plateau. During the research the following tasks were solved: to study the change in total capacity in the surface layer of soil by repeated external pressure, created under different soil moisture; study the change in total capacity in the surface soil layer from the values of the external pressure created at different soil moisture; to study the dependence of the full moisture capacity of the soil to the density summation. The study revealed that the total water capacity is a function of changes in soil density and indirectly depends on the amount of external pressure, its value and soil moisture.


2014 ◽  
Vol 937 ◽  
pp. 578-584
Author(s):  
Qin Jing Li ◽  
Yun Ting Hao ◽  
Li Xue ◽  
Xiao Li Hou

Severe ice-snows caused break of many trees and a lot of crown debris in south China in 2008. Stem damage and crown debris. In order to determine the water holding characteristics of the crown debris, the water holding rate and water absorption rates of crown debris and litter were studied in a Cunninghamia lanceolata stand suffering from ice-snow damage occurring from January to February, 2008. The order of water-holding capacity of the components was leaves > litter > branches> stemwood > stembark in each stage of immersing water. The maximum water holding capacities of stemwood, branch, leaves, stembark and litter were 6.75, 8.13, 10.9, 2.72 and 8.22 t•ha 1, respectively. Maximum water holding rates of stemwood, branch, leaves, stembark and litter were 2271, 2144, 3199, 2800 and 3018 g•kg 1, respectively. Water absorption rate of each component sharply decreased with increasing immersed time from 0.5 to 4 hours, and then slowly decreased. The logarithm equation predicted water-holding capacity and water holding rates of crown debris and litter quite well and the negative exponential equation predicted water absorption rate within an 8.5% error.


Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 162 ◽  
Author(s):  
Beibei Wu ◽  
Beidou Xi ◽  
Xiaosong He ◽  
Xiaojie Sun ◽  
Qian Li ◽  
...  

The microbial oxidation of CH4 in biochar-modified soil cover is considered a potent option for the mitigation of emissions from old landfills or sites containing wastes full of low CH4 generation rates. The mechanism of methane oxidizing bacteria (MOB) can be enhanced by amending the landfill cover soil with biochar, which is recalcitrant to biological degradation and can adsorb CH4 while facilitating the growth and activity of MOB within its porous structure. However, the increase in the permeability coefficient and water content of the cover due to the addition of biochar also affects the methane removal efficiency. A hydrophobic biochar modified by KH-570 was employed to reduce the water content and to promote the diffusion and oxidation of CH4 in the cover. Several series of small-scale column tests were conducted to quantify the CH4 oxidation properties of the landfill cover soil amended with biochar and hydrophobic biochar under different levels of exposed CH4 concentrations (5% and 15%), heights (10–66 cm), and temperatures (15–40 °C). After 30 days of domestication, the removal rate of the hydrophobic biochar-modified soil cover reached 98.8%. The water holding capacity of the cover and the CH4 oxidation efficiency under different moisture contents were investigated in different columns. The hydrophobic biochar-modified soil cover has a weak water holding capacity, low saturated water content, and optimal CH4 oxidation efficiency at this time.


Author(s):  
Yunmin ZENG ◽  
Li'ao WANG ◽  
Tengtun XU ◽  
Xue SONG ◽  
Yanze YANG

ABSTRACTThis study aimed to improve the performance of an intermediate covering of soils in landfill sites by using agents such as calcined lime, sawdust and polyacrylamide (PAM). Compressive strength, permeability and water-holding capacity of modified soils were measured, and the effects of regulating pH and pollutant removal in leachate were also investigated in a leaching experiment. The results indicate that three modifying agents could improve the compressive strength of an intermediate soil cover. The permeability of lime-treated soil increased as the amount of lime increased, while that of sawdust- and PAM-modified soil declined. Results from a leaching experiment show that lime- and sawdust-modified soils could improve leachate quality. The pH value of leachate from 5% lime-modified soils was 7.78, which is suitable for the metabolism of anaerobic microorganisms. The removal efficiencies of chemical oxygen demand, total organic carbon, total nitrogen and volatile fatty acids in leachate permeating lime- and sawdust-modified intermediate cover was improved so that the pollution load of leachate was reduced. The water-holding capacities for 20% sawdust and 0.5% PAM-modified soils were 65.19% and 43.52%, respectively, which helps to maintain the optimum water content of landfill. The water-holding capacity of PAM-modified samples declined in alkaline soil. It is concluded that the combination of 5% sawdust, 5% lime and 90% soil would be optimal for an intermediate covering layer.


2006 ◽  
Vol 7 (5) ◽  
pp. 1090-1112 ◽  
Author(s):  
Sonia I. Seneviratne ◽  
Randal D. Koster ◽  
Zhichang Guo ◽  
Paul A. Dirmeyer ◽  
Eva Kowalczyk ◽  
...  

Abstract Soil moisture memory is a key aspect of land–atmosphere interaction and has major implications for seasonal forecasting. Because of a severe lack of soil moisture observations on most continents, existing analyses of global-scale soil moisture memory have relied previously on atmospheric general circulation model (AGCM) experiments, with derived conclusions that are probably model dependent. The present study is the first survey examining and contrasting global-scale (near) monthly soil moisture memory characteristics across a broad range of AGCMs. The investigated simulations, performed with eight different AGCMs, were generated as part of the Global Land–Atmosphere Coupling Experiment. Overall, the AGCMs present relatively similar global patterns of soil moisture memory. Outliers are generally characterized by anomalous water-holding capacity or biases in radiation forcing. Water-holding capacity is highly variable among the analyzed AGCMs and is the main factor responsible for intermodel differences in soil moisture memory. Therefore, further studies on this topic should focus on the accurate characterization of this parameter for present AGCMs. Despite the range in the AGCMs’ behavior, the average soil moisture memory characteristics of the models appear realistic when compared to available in situ soil moisture observations. An analysis of the processes controlling soil moisture memory in the AGCMs demonstrates that it is mostly controlled by two effects: evaporation’s sensitivity to soil moisture, which increases with decreasing soil moisture content, and runoff’s sensitivity to soil moisture, which increases with increasing soil moisture content. Soil moisture memory is highest in regions of medium soil moisture content, where both effects are small.


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