Effects of Biochar on Infiltration and Evaporation of Soil Water with Sand Mulching

2021 ◽  
Vol 15 (3) ◽  
pp. 369-373
Author(s):  
Wenju Zhao ◽  
Yuhang Liu ◽  
Zongli Li ◽  
Zhiwei Bao
Keyword(s):  
Soil Water ◽  
Agricultural Production ◽  
Arid Regions ◽  
Soil Column ◽  
Agricultural Practices ◽  
Soil Salinization ◽  
Northwestern China ◽  
Wetting Front ◽  
Water Shortages ◽  
Cumulative Infiltration

Water shortages and soil salinization in arid regions of northwestern China have become an important factor limiting agricultural production and affecting the living conditions of farmers. Using existing water resources and salinized land scientifically and efficiently is important for improving agricultural production. We studied the characteristics of the infiltration and evaporation of soil water under the application of different amounts of biochar in indoor soil-column simulations with sand mulching to determine the effect of biochar on the infiltration and evaporation of soil water. We tested five treatments: sand mulching with no biochar (CK) and sand mulching with 0.5, 1.5, 2.5 and 4.5% biochar. Cumulative infiltration and the rate of migration of the wetting front were higher with 0.5 and 1.5% biochar and lower with 2.5 and 4.5% biochar than CK, respectively. The distance and duration of migration of the wetting front followed the power function F = a·tb, a relationship consistent with the Kostiakov model of infiltration. The cumulative evaporation of soil water was higher with 0.5 and 1.5% biochar and lower with 2.5 and 4.5% biochar than CK. The variation of cumulative evaporation was represented well by both the Black and Rose models of evaporation. The results of this study have important implications for the application of biochar in arid regions of northwestern China for improving the hydrological characteristics of soil in agricultural practices.

scholarly journals Water mass balance in the case of vertical infiltration

2013 ◽  
Vol 7 (3) ◽  
pp. 274-280
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Algebraic Model ◽  
Water Infiltration ◽  
Wetting Front ◽  
Retention Curve ◽  
Soil Water Infiltration ◽  
Cumulative Infiltration ◽  
Richard's Equation ◽  
Water Mass Balance

Water movement in the unsaturated zone is an important hydrological process. Richard’s equation is windily used to describe both soil water infiltration and soil water absorption. Various methods have been developed to solve Richard’s equation. Wang et al. (2003) have developed an algebraic model for the description of soil water infiltration, based on Parlange’s solution of Richard’s equation and on soil retention curve and hydraulic conductivity equation given by Brooks and Corey. Their model utilizes experimental measurements of the cumulative infiltration volume and the wetting front distance as functions of time in order to describe soil water infiltration. The objective of this paper is to test the accuracy of the Wang et al. algebraic model for the one-dimensional (vertical) soil water infiltration. A vertical infiltration experiment was conducted on a sandy soil, for the measurement of the cumulative infiltration volume and the wetting front distance. Soil water content was determined at selected times and positions, using gamma ray absorption. Additionally the hydraulic conductivity K(θ) and the soil retention curve Ψ(θ) were determined. The algebraic model developed by Wang et al., was found simple to use since the required data are the cumulative infiltration (F), the wetting front distance (zf) and the initial and saturated soil water content (θi and θs respectively). The results show a fair agreement between calculated and measured values on soil water content profiles, hydraulic conductivity and on the water mass balance.

scholarly journals Wetting Body Characteristics and Infiltration Model of Film Hole Irrigation

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1226
Author(s):  
Fei-long Jie ◽  
Liang-jun Fei ◽  
Yun Zhong ◽  
Li-hua Liu ◽  
Shou-xuan Kang
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Geometric Mean ◽  
Silt Loam ◽  
Wetting Front ◽  
Equivalent Radius ◽  
Volume Model ◽  
Cumulative Infiltration ◽  
Irrigation Volume

Film hole irrigation is a relatively low cost and high efficiency irrigation method, which can significantly improve the efficiency of agricultural water use. In order to establish the quantitative model of film hole irrigation between cumulative infiltration and the wetting body and the irrigation volume model of crops, the infiltration process and wetting body characteristics of four different soils (Xi’an silt loam, silt, silt loam and loam) were studied in laboratory experiments and numerical HYDRUS simulation experiments. The relationship between cumulative infiltration and wetting body radius was established using a mathematical method, and a crop irrigation volume model was proposed based on the root distribution and the required water content of different crops. The experimental results showed that the shape of the wetting body of film hole irrigation is approximately half of the rotating ellipsoid, and the curve shape of the wetting front can be expressed using an elliptic equation. From the center of the film hole to the surface of the wetting front, the soil water content of the wetting body gradually decreases, and the change rate of water content gradually increases, reaching its maximum value near the wetting front. Furthermore, the distribution of water content in the wetting body can be accurately expressed using an elliptic curve equation. The cumulative infiltration of film hole irrigation is proportional to the third power of the equivalent radius of the wetting body, and the equivalent radius is equal to the geometric mean of the horizontal and vertical migration distances of the wetting front. In addition, based on the distribution of crop roots and the demand of crop roots on soil water content, the irrigation model of crops was established. This study provides a theoretical basis for the calculation of the irrigation volume for film hole irrigation under the condition of experiment, and has a guiding significance for the field experiment and application of film hole irrigation in different crops in future.

scholarly journals Effect of Irrigation Water Regimes on Yield of Tetragonia Tetragonioides

Agriculture ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 22 ◽  
Author(s):  
Gulom Bekmirzaev ◽  
Jose Beltrao ◽  
Baghdad Ouddane
Keyword(s):  
Soil Water ◽  
Irrigation Water ◽  
Arid Regions ◽  
Total Yield ◽  
Soil Salinization ◽  
Soluble Carbohydrates ◽  
Water Regimes ◽  
Irrigation Regimes ◽  
Semi Arid ◽  
Tetragonia Tetragonioides

The main purpose of this experiment was to study the effect of several irrigation water regimes on Tetragonia tetragonioides (Pall) O. Kuntze in semi-arid regions. During the experiment period, it was measured that several irrigation regimes were affected in terms of growth, biomass production, total yield, mineral composition, and photosynthetic pigments. The experiment was conducted in the greenhouse at the University of Algarve (Portugal). The study lasted from February to April in 2010. Three irrigation treatments were based on replenishing the 0.25-m-deep pots to field capacity when the soil water level was dropped to 70% (T1, wet treatment), 50% (T2, medium treatment), and 30% (T3, dry treatment) of the available water capacity. The obtained results showed that the leaf mineral compositions of chloride and sodium, the main responsible ions for soil salinization and alkalization in arid and semi-arid regions, enhanced with the decrease in soil water content. However, the minimum amounts of chlorophyll, carotenoids, and soluble carbohydrates in the leaf content were obtained in the medium and driest treatments. On the other hand, growth differences among the several irrigation regimes were very low, and the crop yield increased in the dry treatment compared to the medium treatment; thus, the high capacity of salt-removing species suggested an advantage of its cultivation under dry conditions.

One-Dimensional Vertical Infiltration Characteristics of Red Loam

2014 ◽  
Vol 644-650 ◽  
pp. 5383-5386
Author(s):  
Shen Kai Huang ◽  
Peng Fei Gu ◽  
Xin Yu Zhao ◽  
Qing Bao Pei ◽  
Jin Long Gao
Keyword(s):  
Bulk Density ◽  
Soil Column ◽  
Infiltration Rate ◽  
Experimental Results ◽  
Water Infiltration ◽  
One Dimension ◽  
Column Experiments ◽  
Wetting Front ◽  
One Dimensional ◽  
Cumulative Infiltration

Using a soil column experiments to analyze the influence of different density of one dimension vertical infiltration of water infiltration rate, cumulative infiltration and wetting front. The experimental results showed that the bulk density of the infiltration rate, cumulative infiltration and wetting front has a significant impact. Infiltration rate, cumulative infiltration and wetting front were decreased with increasing density in the same period of infiltration. The greater the soil bulk capacity, the larger the infiltration decrease ration μ and η, respectively compared to the based accumulative infiltration and the based wetting front depth.

Transforming the Rural Agricultural Landscape Through Groundwater Optimisation: Exploring A Chinese-South African Partnership

2018 ◽  
Vol 15 (1) ◽  
Author(s):  
Nirmala Dorasamy ◽  
Olayemi Bakre
Keyword(s):  
South Africa ◽  
South African ◽  
Agricultural Landscape ◽  
Agricultural Practices ◽  
Subsistence Farming ◽  
Water Shortages ◽  
Subsistence Farmers ◽  
Farming Communities ◽  
Standards Of Living ◽  
Kwazulu Natal

The majority of the South African rural populace is directly or indirectly engaged in agricultural practices to earn a livelihood. However, impediments such as climate change, water shortages, and inadequacy of institutional support have undermined these once thriving subsistence farming communities. Furthermore, poor leadership in hydrology, coupled with a lack of depth in skills at all government levels to facilitate the understanding of the importance of groundwater, has made it near impossible for subsistence farmers to benefit optimally from groundwater. The 2012 drought experienced in South Africa paralysed several subsistence farming communities in KwaZulu-Natal. To revamp subsistence farming and assist these farmers across South Africa, the Department of Water and Sanitation launched interventions, but despite the enormous resources expended, indicators (e.g. unsustainable farming practices, poor crop yield, pitiable living conditions, and poor standards of living) provide evidence that these interventions have not yielded the desired results. This paper seeks to suggest practicable interventions aimed at reducing the vulnerability of subsistence farmers in KwaZulu-Natal. The study pursued a qualitative approach in that it solicited the views of experts on groundwater and in related fields to gain an in-depth perspective. Some of the core challenges undermining the sustainability and growth of subsistence farming in the study area were found to be the inadequacy of experts on groundwater, water shortages, institutional deficiencies, lack of political will, and lack of coordination among stakeholders. Pragmatic recommendations are made to address these challenges, among other things to encourage a South African-Chinese partnership in the hydrology sector.

Effects of textural layering on water regimes in sandy soils in a desert-oasis ecotone, Northwestern China

2021 ◽  
Author(s):  
Chengpeng Sun ◽  
Wenzhi Zhao ◽  
Hu Liu ◽  
Yongyong Zhang ◽  
Hong Zhou
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Infiltration ◽  
Northwestern China ◽  
Soil Profiles ◽  
Burial Depth ◽  
Layered Soils ◽  
Water Regimes ◽  
Desert Oasis

<p>Textural layering of soil plays an important role in distributing and regulating resources for plants in many semiarid and arid landscapes. However, the spatial patterns of textural layering and the potential effects on soil hydrology and water regimes are poorly understood, especially in arid sandy soil environments like the desert-oasis ecotones in northwestern China. This work aims to determine the distribution of textural layered soils, analyze the effects of different soil-textural configurations on water regimes, and evaluate which factors affect soil water infiltration and retention characteristics in such a desert-oasis ecotone. We measured soil water content and mineral composition in 87 soil profiles distributed along 3 transects in the study area. Constant-head infiltration experiments were conducted at 9 of the soil profiles with different texture configurations. The results showed that textural layered soils were patchily but extensively distributed throughout the study area (with a combined surface area percentage of about 84%). Soil water content in the profiles ranged from 0.002 to 0.27 g/cm<sup>3</sup> during the investigation period, and significantly and positively correlated with the thickness of a medium-textured (silt or silt loam) layer (<em>P</em> < 0.001). The occurrence of a medium-textured layer increased field capacity (FC) and wilting point (WP), and decreased available water-holding capacity in soil profiles. Burial depth of the medium-textured layer had no clear effects on water retention properties, but the layer thickness tended to. In textural layered soils, smaller water infiltration rate and cumulative infiltration, and shallower depths of wetting fronts were detected, compared with homogeneous sand profiles. The thickness and burial depth of medium-textured layers had obvious effects on infiltration, but the magnitude of the effects depended on soil texture configuration. The revealed patterns of soil textural layering and the potential effects on water regimes may provide new insight into the sustainable management of rainfed vegetation in the desert-oasis ecotones of arid northwestern China and other regions with similar environments around the world.</p>

scholarly journals Effect of Nano-Carbon on Water Holding Capacity in a Sandy Soil of the Loess Plateau

2017 ◽  
Vol 21 (4) ◽  
pp. 189-195 ◽  
Author(s):  
Beibei Zhou ◽  
Xiaopeng Chen
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Loess Plateau ◽  
Sandy Soil ◽  
Water Retention ◽  
Soil Mixture ◽  
Cumulative Infiltration ◽  
Nano Carbon ◽  
Water Contents ◽  
Soil Water Contents

The poor water retention capacity of sandy soils commonly aggregate soil erosion and ecological environment on the Chinese Loess Plateau. Due to its strong capacity for absorption and large specific surface area, the use of nanocarbon made of coconut shell as a soil amendment that could improve water retention was investigated. Soil column experiments were conducted in which a layer of nanocarbon mixed well with the soil was formed at a depth of 20 cm below the soil surface. Four different nanocarbon contents by weight (0%, 0.1%, 0.5%, and 1%) and five thicknesses of the nanocarbon- soil mixture layer ranging from 1 to 5 cm were considered. Cumulative infiltration and soil water content distributions were determined when water was added to soil columns. Soil Water Characteristic Curves (SWCC) were obtained using the centrifuge method. The principal results showed that the infiltration rate and cumulative infiltration increased with the increases of nanocarbon contents, to the thicknesses of the nano carbon-soil mixture layer. Soil water contents that below the soil-nano carbon layer decreased sharply. Both the Brooks-Corey and van Genuchten models could describe well the SWCC of the disturbed sandy soil with various nano carbon contents. Both the saturated water content (θs), residual water content (θr) and empirical parameter (α) increased with increasing nano carbon content, while the pore-size distribution parameter (n) decreased. The available soil water contents were efficiently increased with the increase in nanocarbon contents.

Development of a soil water dispersion index (SOWADIN) for testing the effectiveness of soil-wetting agents

Soil Research ◽  
1989 ◽  
Vol 27 (1) ◽  
pp. 17 ◽  
Author(s):  
Y Sawada ◽  
LAG Aylmore ◽  
JM Hainsworth
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Water Distribution ◽  
Soil Column ◽  
Water Repellent ◽  
Computer Assisted ◽  
Dispersion Index ◽  
Soil Columns ◽  
Water Dispersion ◽  
Soil Wetting

Computer-assisted tomography (CAT) applied to gamma-ray attenuation measurements has been used to develop an index termed the soil water dispersion index (SOWADIN), which describes quantitatively the amount and distribution of water in soil columns. The index, which is determined by classifying pixels in a scanned slice into three categories according to their attenuation coefficients, contains two numerical values. The first value corresponds to the water content of the scanned slice and the second value is a measure of the dispersion of the water throughout the slice. Artificially wetted zones were created in soil columns to give one-third of the scanned layer wetted with various patterns of wetted-area distribution. The SOWADIN values obtained accurately reflected the differences in water distribution associated with the different patterns. Application of SOWADIN to columns of a water-repellent sand before and after treatment with a soil-wetting agent clearly illustrates both the increase in water content and improvement in water distribution in the soil column following treatment.

scholarly journals Atmospheric Optical Turbulence Profile Measurement and Model Improvement over Arid and Semi-arid regions

2021 ◽  
Author(s):  
Hao Yang ◽  
Zhiyuan Fang ◽  
Cheng Li ◽  
Xu Deng ◽  
Kunming Xing ◽  
...  
Keyword(s):  
Observational Data ◽  
Arid Regions ◽  
Northwestern China ◽  
Profile Measurement ◽  
Height Distribution ◽  
Optical Turbulence ◽  
Different Seasons ◽  
Combined Action ◽  
Model Improvement ◽  
Improved Model

Abstract. From August 4th to 30th, 2020 and from November 27th to December 25th, 2020, a self-developed radiosonde balloon system was used to observe high-altitude atmospheric optical turbulence at three sites in northwestern China, and an improved model based on the observational data was established. Through comparative analysis of the observational data and the improved model, the distribution characteristics of atmospheric optical turbulence under the combined action of different meteorological parameters and different landform features in different seasons were obtained. The improved model can show the variation of the detailed characteristics of turbulence with the height distribution, and the degree of correlation with the measured values is above 0.82. The improved model can provide a theoretical basis and supporting data for turbulence estimation and forecasting in northwestern China.

scholarly journals Relating surface backscatter response from TRMM Precipitation Radar to soil moisture: results over a semi-arid region

2009 ◽  
Vol 6 (5) ◽  
pp. 6425-6454
Author(s):  
H. Stephen ◽  
S. Ahmad ◽  
T. C. Piechota ◽  
C. Tang
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Arid Regions ◽  
Vegetation Index ◽  
Temporal Trends ◽  
Model Parameters ◽  
Precipitation Radar ◽  
Semi Arid

Abstract. The Tropical Rainfall Measuring Mission (TRMM) carries aboard the Precipitation Radar (TRMMPR) that measures the backscatter (σ°) of the surface. σ° is sensitive to surface soil moisture and vegetation conditions. Due to sparse vegetation in arid and semi-arid regions, TRMMPR σ° primarily depends on the soil water content. In this study we relate TRMMPR σ° measurements to soil water content (ms) in Lower Colorado River Basin (LCRB). σ° dependence on ms is studied for different vegetation greenness values determined through Normalized Difference Vegetation Index (NDVI). A new model of σ° that couples incidence angle, ms, and NDVI is used to derive parameters and retrieve soil water content. The calibration and validation of this model are performed using simulated and measured ms data. Simulated ms is estimated using Variable Infiltration Capacity (VIC) model whereas measured ms is acquired from ground measuring stations in Walnut Gulch Experimental Watershed (WGEW). σ° model is calibrated using VIC and WGEW ms data during 1998 and the calibrated model is used to derive ms during later years. The temporal trends of derived ms are consistent with VIC and WGEW ms data with correlation coefficient (R) of 0.89 and 0.74, respectively. Derived ms is also consistent with the measured precipitation data with R=0.76. The gridded VIC data is used to calibrate the model at each grid point in LCRB and spatial maps of the model parameters are prepared. The model parameters are spatially coherent with the general regional topography in LCRB. TRMMPR σ° derived soil moisture maps during May (dry) and August (wet) 1999 are spatially similar to VIC estimates with correlation 0.67 and 0.76, respectively. This research provides new insights into Ku-band σ° dependence on soil water content in the arid regions.

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