Soil Water Dynamics Under Different Land Uses in Loess Hilly Region in China by Stable Isotopic Tracing

Exploring soil water dynamics under different land use types is important for water resource management and vegetation restoration in the Loess Plateau. In this study, we investigated the hydrogen and oxygen isotopic compositions of soil water from four different land use types to explore the mechanism of soil water movement and transformation and analyse the influence of land use. The results show that the range of stable isotopes (δD and δ18O) in soil water was smaller than that in precipitation. Values for δD and δ18O in soil water showed relatively similar temporal variation, heavy isotopes were enriched in the soil water in July and depleted in October. Stable isotope values in shallow (<100 cm depth) soil water and deep (>200 cm depth) soil water were low. The δD and δ18O values in woodlands decreased gradually with increasing depth. Across the four land use types, the maximum variation in δD and δ18O was in the shallow depth of the soil profile. Groundwater was recharged mainly from precipitation and then from soil water. The ratio of groundwater recharge by soil water under different land use types followed this rank order: woodland (35.70%) > grassland (31.14%) > shrubland (29.47%) > cropland (29.18%). Matrix flow and preferential flow coexisted during infiltration, and the occurrence of preferential flow was related to the land use type. The main reason for the variation in isotopic composition in soil water is the difference in soil evaporation, which is influenced by different vegetation cover. Owing to the difference in soil evaporation and fractionation, precipitation on cropland, shrubland, and grassland can recharge more soil water than on woodland.

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Soil water dynamics under artificial Caragana microphylla shrub in the loess hilly region of Northwest Shanxi Province

CHINESE JOURNAL OF ECO-AGRICULTURE ◽

10.3724/sp.j.1011.2010.00352 ◽

2010 ◽

Vol 18 (2) ◽

pp. 352-355 ◽

Cited By ~ 1

Author(s):

Zhi-Pin YANG ◽

Qiang ZHANG ◽

Yong-Liang WANG ◽

Jian-Jie ZHANG ◽

Rui-Rui JI

Keyword(s):

Soil Water ◽

Water Dynamics ◽

Shanxi Province ◽

Soil Water Dynamics ◽

Caragana Microphylla ◽

Hilly Region ◽

Loess Hilly Region

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Analysis of Soil Water Response to Grass Transpiration

Soil and Water Research ◽

10.17221/6510-swr ◽

2013 ◽

Vol 1 (No. 3) ◽

pp. 85-98

Author(s):

Dohnal Michal ◽

Dušek Jaromír ◽

Vogel Tomáš ◽

Herza Jiří

Keyword(s):

Soil Water ◽

Water Uptake ◽

Preferential Flow ◽

Water Movement ◽

Control Volume ◽

Water Pressure ◽

Lower Boundary ◽

Root Water Uptake ◽

Water Dynamics ◽

Soil Water Dynamics

This paper focuses on numerical modelling of soil water movement in response to the root water uptake that is driven by transpiration. The flow of water in a lysimeter, installed at a grass covered hillslope site in a small headwater catchment, is analysed by means of numerical simulation. The lysimeter system provides a well defined control volume with boundary fluxes measured and soil water pressure continuously monitored. The evapotranspiration intensity is estimated by the Penman-Monteith method and compared with the measured lysimeter soil water loss and the simulated root water uptake. Variably saturated flow of water in the lysimeter is simulated using one-dimensional dual-permeability model based on the numerical solution of the Richards’ equation. The availability of water for the root water uptake is determined by the evaluation of the plant water stress function, integrated in the soil water flow model. Different lower boundary conditions are tested to compare the soil water dynamics inside and outside the lysimeter. Special attention is paid to the possible influence of the preferential flow effects on the lysimeter soil water balance. The adopted modelling approach provides a useful and flexible framework for numerical analysis of soil water dynamics in response to the plant transpiration.

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Modeling Effects of Land use and Vegetation Density on Soil Water Dynamics: Implications on Water Resource Management

Water Resources Management ◽

10.1007/s11269-014-0599-x ◽

2014 ◽

Vol 28 (7) ◽

pp. 2063-2076 ◽

Cited By ~ 26

Author(s):

Dongli She ◽

Dongdong Liu ◽

Yongqiu Xia ◽

Ming’an Shao

Keyword(s):

Land Use ◽

Resource Management ◽

Soil Water ◽

Water Resource ◽

Water Resource Management ◽

Water Dynamics ◽

Vegetation Density ◽

Soil Water Dynamics ◽

Effects Of Land Use

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Modeling long-term soil water dynamics in response to land-use change in a semi-arid area

Journal of Hydrology ◽

10.1016/j.jhydrol.2020.124824 ◽

2020 ◽

Vol 585 ◽

pp. 124824 ◽

Cited By ~ 4

Author(s):

Xiao Bai ◽

Xiaoxu Jia ◽

Yuhua Jia ◽

Ming'an Shao ◽

Wei Hu

Keyword(s):

Land Use ◽

Land Use Change ◽

Soil Water ◽

Arid Area ◽

Water Dynamics ◽

Soil Water Dynamics ◽

Semi Arid

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Soil water dynamics and yield in maize and Brachiaria ruziziensis intercropping

Pesquisa Agropecuária Tropical ◽

10.1590/1983-40632020v5059809 ◽

2020 ◽

Vol 50 ◽

Author(s):

Gabriela Sabrine França Silva ◽

Aderson Soares de Andrade Júnior ◽

Milton José Cardoso ◽

Raimundo Bezerra de Araújo Neto

Keyword(s):

Land Use ◽

Grain Yield ◽

Soil Water ◽

Time Domain Reflectometry ◽

Water Dynamics ◽

Soil Water Dynamics ◽

Land Use Efficiency ◽

Brachiaria Ruziziensis ◽

High Plant Density ◽

Use Efficiency

ABSTRACT In intercropping systems, a high plant density can delay the biomass accumulation and affect the water availability to plants. This study aimed to evaluate the soil water dynamics and the crop yield performance in maize and Brachiaria ruziziensis intercropping under different sowing densities of the forage grass. The experiment was conducted in a randomized block design, with treatments associated to the sowing densities (2 kg ha-1, 4 kg ha-1, 6 kg ha-1 and 8 kg ha-1) and the single cropping for both species as controls. The maize plants were evaluated for grain yield and B. ruziziensis for number of plants per hectare and shoot fresh and dry matter. The intercropping performance was evaluated using the land-use efficiency index. The soil water dynamics was monitored in two soil depths (0-0.3 m and 0.3-0.6 m) by using the time domain reflectometry method. The evaluation of soil water storage was carried out from plots with four of the crop systems (single maize or B. ruziziensis, and intercropping with the extreme sowing densities), at four different times. The increase in the sowing density of B. ruziziensis decreased the grain yield of the intercropped maize by 30.8 %. The intercropping system using 2 kg ha-1 of the grass seeds resulted in the best land-use efficiency (23 %). In addition, the intercropping treatments promoted a higher extraction of water from the soil, mainly at the maize growth stages with higher hydric demand (e.g., flowering and grain filling). These systems stimulate the extraction of water from deeper soil layers, when compared to maize in single cropping.

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Spatial–Temporal Soil Water Dynamics beneath a Tree Monitored by Tensiometer-Time Domain Reflectometry Probes

Water ◽

10.3390/w11081662 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1662

Author(s):

Sheng-Lun Li ◽

Wei-Li Liang

Keyword(s):

Soil Water ◽

Time Domain ◽

Preferential Flow ◽

Hot Spot ◽

Soil Water Potential ◽

Time Domain Reflectometry ◽

Water Dynamics ◽

Cold Spot ◽

Soil Water Dynamics ◽

Matrix Flow

Tensiometer-coiled time domain reflectometry (T-TDR) probes have been developed in previous studies, but have not been applied in the field. In this study, we applied T-TDR probes to the simultaneous monitoring of soil water content (θ) and soil water potential (ψ) on a profile beneath a tree in a forest stand, and analyzed the temporal and spatial variations in soil water dynamics in a root-containing environment. The results showed different features in the relationships between the mean and standard deviation of spatial θ and ψ, which exhibited convex-upward shapes and negative curvilinear shapes, respectively. High spatial variability was observed at intermediate values of θ and small values of ψ. Matrix flow and preferential flow accounted for 75% and 25% of the area beneath the tree. Although the infiltration processes were dominated by matrix flow, preferential flow acting for a short time could cause an average θ or ψ to reach their maximum values at all of the locations. Preferential flow primarily occurred at a “hot spot” around a coarse root. Small changes in θ and ψ were generally observed at a “cold spot” beneath a lateral root. Integrated information from multiple sources of θ and ψ could help to evaluate soil water dynamics when one exhibited large spatial variation during the wetting or drying processes, and greatly help to improve the accuracy for detecting the presence of preferential flow in a short measurement period.

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Investigating effects of different evapotranspiration (ET) schemes on soil water dynamics and ET partitioning: a large lysimeter case of summer maize in a semi-arid environment northwest of China

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-12-9977-2015 ◽

2015 ◽

Vol 12 (9) ◽

pp. 9977-10022 ◽

Cited By ~ 3

Author(s):

L. Yu ◽

Y. Zeng ◽

Z. Su ◽

H. Cai ◽

Z. Zheng

Keyword(s):

Soil Water ◽

Land Surface ◽

Coupled Model ◽

Growing Season ◽

Arid Environment ◽

Soil Evaporation ◽

Water Dynamics ◽

Rooting Depth ◽

Crop Evapotranspiration ◽

Soil Water Dynamics

Abstract. Different evapotranspiration (ET) schemes can affect significantly the performance of land surface models in capturing the soil water dynamics and ET partitioning over various land cover and climates, the accurate understanding of which is crucial to determine the effective irrigation. In this study, a land model considering the coupled transfer of water, vapor and heat in the soil, with two alternative ET schemes, was used to investigate how the coupled mechanism can affect the soil water dynamics in a crop field and how the ET partitioning was influenced. There are two different evapotranspiration (ET) schemes, one is based on reference crop evapotranspiration (ET0) and use LAI to partition into soil evaporation and transpiration, denoted as the ETind scheme; the other is one-step calculation of actual soil evaporation and potential transpiration by incorporating canopy minimum resistance and actual soil resistance into Penman–Monteith model, denoted as the ETdir scheme. Results indicated that the coupled model with the two different ET schemes differed in simulating soil water content and crop evapotranspiration components while agreed well for the simulation of soil temperature. Considering the aerodynamic and surface resistance terms made the ETdir scheme better in simulating soil evaporation especially after irrigations. Furthermore, the results of different crop growth scenarios indicated that the uncertainty in LAI played an important role in estimating the relative transpiration and evaporation fraction. The soil drying seemed to intensify the disturbance of maximum rooting depth and root growth rate in calculating ET components. The former was more important at the late growing season while the latter dominated at the early growing season.

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The effect of different evapotranspiration methods on portraying soil water dynamics and ET partitioning in a semi-arid environment in Northwest China

Hydrology and Earth System Sciences ◽

10.5194/hess-20-975-2016 ◽

2016 ◽

Vol 20 (3) ◽

pp. 975-990 ◽

Cited By ~ 17

Author(s):

Lianyu Yu ◽

Yijian Zeng ◽

Zhongbo Su ◽

Huanjie Cai ◽

Zhen Zheng

Keyword(s):

Growth Rate ◽

Soil Water ◽

Growing Season ◽

Soil Evaporation ◽

Water Dynamics ◽

Rooting Depth ◽

Crop Evapotranspiration ◽

Soil Water Dynamics ◽

The Impact ◽

Root Growth Rate

Abstract. Different methods for assessing evapotranspiration (ET) can significantly affect the performance of land surface models in portraying soil water dynamics and ET partitioning. An accurate understanding of the impact a method has is crucial to determining the effectiveness of an irrigation scheme. Two ET methods are discussed: one is based on reference crop evapotranspiration (ET0) theory, uses leaf area index (LAI) for partitioning into soil evaporation and transpiration, and is denoted as the ETind method; the other is a one-step calculation of actual soil evaporation and potential transpiration by incorporating canopy minimum resistance and actual soil resistance into the Penman–Monteith model, and is denoted as the ETdir method. In this study, a soil water model, considering the coupled transfer of water, vapor, and heat in the soil, was used to investigate how different ET methods could affect the calculation of the soil water dynamics and ET partitioning in a crop field. Results indicate that for two different ET methods this model varied concerning the simulation of soil water content and crop evapotranspiration components, but the simulation of soil temperature agreed well with lysimeter observations, considering aerodynamic and surface resistance terms improved the ETdir method regarding simulating soil evaporation, especially after irrigation. Furthermore, the results of different crop growth scenarios indicate that the uncertainty in LAI played an important role in estimating the relative transpiration and evaporation fraction. The impact of maximum rooting depth and root growth rate on calculating ET components might increase in drying soil. The influence of maximum rooting depth was larger late in the growing season, while the influence of root growth rate dominated early in the growing season.

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