The effects of shallow saline groundwater on evaporation, soil moisture, and temperature distribution in the presence of straw mulch

Abstract Mitigating evaporative water loss from terrestrial surfaces is of central importance to water resources management in arid and semi-arid regions. This study was intended to experimentally address the effect of straw mulch layer on soil evaporation and temperature distribution in the presence of shallow saline groundwater. A factorial-based experiment with a completely randomized design was carried out in mini-lysimeters (MLs) with different concentrations of saline groundwater and soil types, with and without straw mulch. The lysimeters were placed on the soil surface in the field. Water table in MLs was kept at the depth of 60 cm, and evaporation rate, soil moisture content, soil salinity, and temperature were continuously monitored. The analysis of variance (ANOVA) indicated significant differences in the soil evaporation rates due to the effects of soil types (i.e., loam and sand) and straw mulch (p < 0.01). The results showed that soil temperature fluctuations at the 5 cm depth in loamy soil with and without mulch were 11.5 and 17.5 °C, while in sandy soil the fluctuations rates were 15 and 18.5 °C, respectively. The application of a mulch layer was found to significantly reduce the evaporative loss by 27 and 8% in loamy and sandy soils, respectively.

Download Full-text

The Influence of Moss Colonization and Biochar Application on Evaporation Losses and Surface Crack in Shallow Carbonate–Derived Laterite During Dry–Wet Cycles

10.21203/rs.3.rs-1109021/v1 ◽

2021 ◽

Author(s):

Lulu Che ◽

Dongdong Liu ◽

Dongli She

Keyword(s):

Soil Moisture ◽

Soil Surface ◽

Soil Evaporation ◽

Interactive Effects ◽

Surface Cracks ◽

Evaporation Model ◽

Soil Desiccation ◽

Evaporation Losses ◽

Soil Moisture Conservation ◽

Surface Temperature Field

Abstract AimsSoil water deficit in karst mountain lands is becoming an issue of concern owing to porous, fissured, and soluble nature of underlying karst bedrock. It is important to identify feasible methods to facilitate soil water preservation in karst mountainous lands. This study aims to seek the possibility of combined utilization of moss colonization and biochar application to reduce evaporation losses in carbonate-derived laterite.MethodsThe treatments of the experiments at micro-lysimeter included four moss spore amounts (0, 30, 60, and 90 g·m−2) and four biochar application levels (0, 100, 400, and 700 g·m−3). The dynamics of moss coverage, characteristics of soil surface cracks and surface temperature field were identified. An empirical evaporation model considering the interactive effects of moss colonization and biochar application was proposed and assessed.ResultsMoss colonization reduced significantly the ratio of soil desiccation cracks. Relative cumulative evaporation decreased linearly with increasing moss coverage under four biochar application levels. Biochar application reduced critical moss coverage associated with inhibition of evaporation by 33.26%-44.34%. The empirical evaporation model enabled the calculation of soil evaporation losses under moss colonization and biochar application, with the R2 values ranging from 0.94 to 0.99.Conclusions Our result showed that the artificially cultivated moss, which was induced by moss spores and biochar, decreased soil evaporation by reducing soil surface cracks, increasing soil moisture and soil surface temperature.Moss colonization and biochar application has the potential to facilitate soil moisture conservation in karst mountain lands.

Download Full-text

Stem–root flow effect on soil–atmosphere interactions and uncertainty assessments

Hydrology and Earth System Sciences ◽

10.5194/hess-20-1509-2016 ◽

2016 ◽

Vol 20 (4) ◽

pp. 1509-1522

Author(s):

Tzu-Hsien Kuo ◽

Jen-Ping Chen ◽

Yongkang Xue

Keyword(s):

Heat Flux ◽

Soil Moisture ◽

Diffusion Processes ◽

Sensible Heat Flux ◽

Soil Layer ◽

Soil Surface ◽

Soil Evaporation ◽

Soil Layers ◽

Flow Effect ◽

Top Soil

Abstract. Rainfall that reaches the soil surface can rapidly move into deeper layers in the form of bulk flow through the stem–root flow mechanism. This study developed the stem–root flow parameterization scheme and coupled this scheme with the Simplified Simple Biosphere model (SSiB) to analyze its effects on land–atmospheric interactions. The SSiB model was tested in a single-column mode using the Lien Hua Chih (LHC) measurements conducted in Taiwan and HAPEX–Mobilhy (HAPEX) measurements in France. The results show that stem–root flow generally caused a decrease in soil moisture in the top soil layer and moistened the deeper soil layers. Such soil moisture redistribution results in substantial changes in heat flux exchange between land and atmosphere. In the humid environment at LHC, the stem–root flow effect on transpiration was minimal, and the main influence on energy flux was through reduced soil evaporation that led to higher soil temperature and greater sensible heat flux. In the Mediterranean environment of HAPEX, the stem–root flow substantially affected plant transpiration and soil evaporation, as well as associated changes in canopy and soil temperatures. However, the effect on transpiration could be either positive or negative depending on the relative changes in the soil moisture of the top soil vs. deeper soil layers due to stem–root flow and soil moisture diffusion processes.

Download Full-text

Dead coverage as soil conservationist practice

Scientific Electronic Archives ◽

10.36560/1242019734 ◽

2019 ◽

Vol 12 (4) ◽

pp. 30

Author(s):

H. Cândido ◽

D. Silva

Keyword(s):

Soil Moisture ◽

Soil Conservation ◽

Sandy Loam ◽

Soil Surface ◽

Mato Grosso ◽

Surface Moisture ◽

Randomized Design ◽

Loam Soil ◽

Completely Randomized Design ◽

Erosion Loss

Soil degradation and erosion loss due to inadequate management pose a serious threat to agricultural productivity and contribute to the aggravation of environmental impacts. Soil, vegetative and mechanical practices of soil conservation are being developed to assist in the attenuation of these problems. The present research was carried out with the objective of evaluating the effect of mulching in the conversation of a sandy loam soil in the state of Mato Grosso. The study was developed under field conditions at the Federal University of Mato Grosso, Rondonópolis Campus and a completely randomized design with two treatments, with and without vegetation cover, where soil temperature, spontaneous plant quantification, soil moisture and relative humidity of the soil surface. It was verified that mulching kept the soil with a temperature gradient around two degrees lower than the uncovered treatment, besides reducing the emergence of spontaneous plants in 36 times and raising soil moisture by approximately four degrees, but not had an effect on soil surface moisture. Therefore, the use of mulch is an advantageous practice, which improves the hydrothermal characteristics of the soil and reduces the incidence of spontaneous plants

Download Full-text

A study of the sensitivity of bare soil evaporation schemes to soil surface wetness, using the coupled soil moisture and surface temperature prediction model, BARESOIL

Meteorology and Atmospheric Physics ◽

10.1007/bf01029605 ◽

1995 ◽

Vol 55 (1-2) ◽

pp. 101-112 ◽

Cited By ~ 9

Author(s):

Lj. Dekić ◽

D. T. Mihailović ◽

B. Rajković

Keyword(s):

Soil Moisture ◽

Prediction Model ◽

Surface Temperature ◽

Soil Surface ◽

Bare Soil ◽

Soil Evaporation ◽

Temperature Prediction ◽

Surface Wetness ◽

Bare Soil Evaporation

Download Full-text

SOIL TEMPERATURE AND SOIL WATER UNDER ZERO TILLAGE IN MANITOBA

Canadian Journal of Soil Science ◽

10.4141/cjss82-035 ◽

1982 ◽

Vol 62 (2) ◽

pp. 311-325 ◽

Cited By ~ 33

Author(s):

E. GAUER ◽

C. F. SHAYKEWICH ◽

E. H. STOBBE

Keyword(s):

Soil Moisture ◽

Soil Temperature ◽

Soil Water ◽

Soil Surface ◽

Conventional Tillage ◽

Soil Types ◽

Zero Tillage ◽

Crop Canopy ◽

Burned Soil

The influences of zero and conventional tillage on soil temperature and soil moisture were investigated on three soil types in Manitoba. When the straw was spread on the soil surface, zero-tilled fields were usually cooler than conventionally tilled fields. When the straw was removed by raking, the opposite was true. No consistent soil temperature differences occurred between conventional and zero-tilled soils when the straw was burned. Soil moisture was higher on the zero- than on conventionally tilled plots both when straw was spread on the surface and when the straw was removed by raking. No moisture differences occurred between the tilled and zero-tilled plots when the straw was burned. As the season progressed, differences in moisture and temperature decreased as the crop canopy developed, and as the straw and stubble disintegrated.

Download Full-text

Ecohydrologic controls on vegetation density and evapotranspiration partitioning across the climatic gradients of the central United States

Hydrology and Earth System Sciences ◽

10.5194/hess-14-2121-2010 ◽

2010 ◽

Vol 14 (10) ◽

pp. 2121-2139 ◽

Cited By ~ 10

Author(s):

J. P. Kochendorfer ◽

J. A. Ramírez

Keyword(s):

United States ◽

Soil Moisture ◽

Water Balance ◽

Soil Water ◽

Soil Surface ◽

Soil Evaporation ◽

Soil Water Balance ◽

Vegetation Density ◽

Study Region ◽

Central United States

Abstract. The soil-water balance and plant water use are investigated over a domain encompassing the central United States using the Statistical-Dynamical Ecohydrology Model (SDEM). The seasonality in the model and its use of the two-component Shuttleworth-Wallace canopy model allow for application of an ecological optimality hypothesis in which vegetation density, in the form of peak green leaf area index (LAI), is maximized, within upper and lower bounds, such that, in a typical season, soil moisture in the latter half of the growing season just reaches the point at which water stress is experienced. Via a comparison to large-scale estimates of grassland productivity, modeled-determined peak green LAI for these systems is seen to be at least as accurate as the unaltered satellite-based observations on which they are based. A related feature of the SDEM is its partitioning of evapotranspiration into transpiration, evaporation from canopy interception, and evaporation from the soil surface. That partitioning is significant for the soil-water balance because the dynamics of the three processes are very different. Surprising little dependence on climate and vegetation type is found for the percentage of total evapotranspiration that is soil evaporation, with most of the variation across the study region attributable to soil texture and the resultant differences in vegetation density. While empirical evidence suggests that soil evaporation in the forested regions of the most humid part of the study region is somewhat overestimated, model results are in excellent agreement with observations from croplands and grasslands. The implication of model results for water-limited vegetation is that the higher (lower) soil moisture content in wetter (drier) climates is more-or-less completely offset by the greater (lesser) amount of energy available at the soil surface. This contrasts with other modeling studies which show a strong dependence of evapotranspiration partitioning on climate.

Download Full-text

Seasonal activity and estivation of lumbricid earthworms in the midlands of Tasmania

Soil Research ◽

10.1071/sr9941355 ◽

1994 ◽

Vol 32 (6) ◽

pp. 1355 ◽

Cited By ~ 12

Author(s):

RB Garnsey

Keyword(s):

Soil Moisture ◽

Adult Development ◽

Survival Rates ◽

Soil Surface ◽

Early Spring ◽

Lumbricus Rubellus ◽

Late Winter ◽

Cocoon Production ◽

Density And Biomass ◽

Earthworm Activity

Earthworms have the ability to alleviate many soil degradational problems in Australia. An attempt to optimize this resource requires fundamental understanding of earthworm ecology. This study reports the seasonal changes in earthworm populations in the Midlands of Tasmania (<600 mm rainfall p.a.), and examines, for the first time in Australia, the behaviour and survival rates of aestivating earthworms. Earthworms were sampled from 14 permanent pastures in the Midlands from May 1992 to February 1994. Earthworm activity was significantly correlated with soil moisture; maximum earthworm activity in the surface soil was evident during the wetter months of winter and early spring, followed by aestivation in the surface and subsoils during the drier summer months. The two most abundant earthworm species found in the Midlands were Aporrectodea caliginosa (maximum of 174.8 m-2 or 55.06 g m-2) and A. trapezoides (86 m-2 or 52.03 g m-2), with low numbers of Octolasion cyaneum, Lumbricus rubellus and A. rosea. The phenology of A. caliginosa relating to rainfall contrasted with that of A. trapezoides in this study. A caliginosa was particularly dependent upon rainfall in the Midlands: population density, cocoon production and adult development of A. caliginosa were reduced as rainfall reduced from 600 to 425 mm p.a. In contrast, the density and biomass of A. trapezoides were unaffected by rainfall over the same range: cocoon production and adult development continued regardless of rainfall. The depth of earthworm aestivation during the summers of 1992-94 was similar in each year. Most individuals were in aestivation at a depth of 150-200 mm, regardless of species, soil moisture or texture. Smaller aestivating individuals were located nearer the soil surface, as was shown by an increase in mean mass of aestivating individuals with depth. There was a high mortality associated with summer aestivation of up to 60% for juvenile, and 63% for adult earthworms in 1993 in the Midlands. Cocoons did not survive during the summers of 1992 or 1994, but were recovered in 1993, possibly due to the influence of rainfall during late winter and early spring.

Download Full-text