Year‐Round Transpiration Dynamics Linked With Deep Soil Moisture in a Warm Desert Shrubland

Soil moisture mapping at a regional scale is commonplace since these data are required in many applications, such as hydrological and agricultural analyses. The use of remotely sensed data for the estimation of deep soil moisture at a regional scale has received far less emphasis. The objective of this study was to map the 500-m, 8-day average and daily soil moisture at different soil depths in Oklahoma from remotely sensed and ground-measured data using the random forest (RF) method, which is one of the machine-learning approaches. In order to investigate the estimation accuracy of the RF method at both a spatial and a temporal scale, two independent soil moisture estimation experiments were conducted using data from 2010 to 2014: a year-to-year experiment (with a root mean square error (RMSE) ranging from 0.038 to 0.050 m3/m3) and a station-to-station experiment (with an RMSE ranging from 0.044 to 0.057 m3/m3). Then, the data requirements, importance factors, and spatial and temporal variations in estimation accuracy were discussed based on the results using the training data selected by iterated random sampling. The highly accurate estimations of both the surface and the deep soil moisture for the study area reveal the potential of RF methods when mapping soil moisture at a regional scale, especially when considering the high heterogeneity of land-cover types and topography in the study area.

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Seasonal variation of deep soil moisture under different land uses on the semi-arid Loess Plateau of China

Journal of Soils and Sediments ◽

10.1007/s11368-018-2119-8 ◽

2018 ◽

Vol 19 (3) ◽

pp. 1179-1189 ◽

Cited By ~ 2

Author(s):

Bowei Yu ◽

Gaohuan Liu ◽

Qingsheng Liu ◽

Chong Huang ◽

He Li ◽

...

Keyword(s):

Soil Moisture ◽

Seasonal Variation ◽

Loess Plateau ◽

Land Uses ◽

Deep Soil ◽

Semi Arid

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Developmental and physiological traits associated with high yield and stay-green phenotype in wheat

Australian Journal of Agricultural Research ◽

10.1071/ar07193 ◽

2008 ◽

Vol 59 (4) ◽

pp. 354 ◽

Cited By ~ 106

Author(s):

J. T. Christopher ◽

A. M. Manschadi ◽

G. L. Hammer ◽

A. K. Borrell

Keyword(s):

Soil Moisture ◽

Grain Filling ◽

High Yield ◽

Limiting Factor ◽

Deep Soil ◽

Stay Green ◽

Physiological Basis ◽

Winter Crops ◽

Significant Yield ◽

Grain Filling Period

Water availability is a key limiting factor in wheat production in the northern grain belt of Australia. Varieties with improved adaptation to such conditions are actively sought. The CIMMYT wheat line SeriM82 has shown a significant yield advantage in multi-environment screening trials in this region. The objective of this study was to identify the physiological basis of the adaptive traits underpinning this advantage. Six detailed experiments were conducted to compare the growth, development, and yield of SeriM82 with that of the adapted cultivar, Hartog. The experiments were undertaken in field environments that represented the range of moisture availability conditions commonly encountered by winter crops grown on the deep Vertosol soils of this region. The yield of SeriM82 was 6–28% greater than that of Hartog, and SeriM82 exhibited a stay-green phenotype by maintaining green leaf area longer during the grain-filling period in all environments where yield was significantly greater than Hartog. However, where the availability of deep soil moisture was limited, SeriM82 failed to exhibit significantly greater yield or to express the stay-green phenotype. Thus, the stay-green phenotype was closely associated with the yield advantage of SeriM82. SeriM82 also exhibited higher mean grain mass than Hartog in all environments. It is suggested that small differences in water use before anthesis, or greater water extraction from depth after anthesis, could underlie the stay-green phenotype. The inability of SeriM82 to exhibit stay-green and higher yield where deep soil moisture was depleted indicates that extraction of deep soil moisture is important.

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Positionally-independent and Extended Read Range Resonant Sensors Applied to Deep Soil Moisture Monitoring

Sensors and Actuators A Physical ◽

10.1016/j.sna.2021.113227 ◽

2021 ◽

pp. 113227

Author(s):

Yee Jher Chan ◽

Adam R. Carr ◽

Subhanwit Roy ◽

Caden M. Washburn ◽

Nathan Neihart ◽

...

Keyword(s):

Soil Moisture ◽

Deep Soil ◽

Resonant Sensors ◽

Read Range ◽

Soil Moisture Monitoring

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Variations of deep soil moisture under different vegetation types and influencing factors in a watershed of the Loess Plateau, China

Hydrology and Earth System Sciences ◽

10.5194/hess-20-3309-2016 ◽

2016 ◽

Vol 20 (8) ◽

pp. 3309-3323 ◽

Cited By ~ 35

Author(s):

Xuening Fang ◽

Wenwu Zhao ◽

Lixin Wang ◽

Qiang Feng ◽

Jingyi Ding ◽

...

Keyword(s):

Soil Moisture ◽

Influencing Factors ◽

Loess Plateau ◽

Vegetation Restoration ◽

Native Vegetation ◽

Watershed Scale ◽

Vegetation Types ◽

Deep Soil ◽

Soil Layers ◽

Management Measures

Abstract. Soil moisture in deep soil layers is a relatively stable water resource for vegetation growth in the semi-arid Loess Plateau of China. Characterizing the variations in deep soil moisture and its influencing factors at a moderate watershed scale is important to ensure the sustainability of vegetation restoration efforts. In this study, we focus on analyzing the variations and factors that influence the deep soil moisture (DSM) in 80–500 cm soil layers based on a soil moisture survey of the Ansai watershed in Yan'an in Shanxi Province. Our results can be divided into four main findings. (1) At the watershed scale, higher variations in the DSM occurred at 120–140 and 480–500 cm in the vertical direction. At the comparable depths, the variation in the DSM under native vegetation was much lower than that in human-managed vegetation and introduced vegetation. (2) The DSM in native vegetation and human-managed vegetation was significantly higher than that in introduced vegetation, and different degrees of soil desiccation occurred under all the introduced vegetation types. Caragana korshinskii and black locust caused the most serious desiccation. (3) Taking the DSM conditions of native vegetation as a reference, the DSM in this watershed could be divided into three layers: (i) a rainfall transpiration layer (80–220 cm); (ii) a transition layer (220–400 cm); and (iii) a stable layer (400–500 cm). (4) The factors influencing DSM at the watershed scale varied with vegetation types. The main local controls of the DSM variations were the soil particle composition and mean annual rainfall; human agricultural management measures can alter the soil bulk density, which contributes to higher DSM in farmland and apple orchards. The plant growth conditions, planting density, and litter water holding capacity of introduced vegetation showed significant relationships with the DSM. The results of this study are of practical significance for vegetation restoration strategies, especially for the choice of vegetation types, planting zones, and proper human management measures.

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Effects of Climate Variability on Water Storage in the Colorado River Basin

Journal of Hydrometeorology ◽

10.1175/2009jhm1133.1 ◽

2009 ◽

Vol 10 (5) ◽

pp. 1257-1270 ◽

Cited By ~ 11

Author(s):

Ruud Hurkmans ◽

Peter A. Troch ◽

Remko Uijlenhoet ◽

Paul Torfs ◽

Matej Durcik

Keyword(s):

Soil Moisture ◽

River Basin ◽

Colorado River ◽

Decadal Variability ◽

Southern Oscillation ◽

Water Storage ◽

Low Frequency ◽

Colorado River Basin ◽

Climate Indices ◽

Deep Soil

Abstract Understanding the long-term (interannual–decadal) variability of water availability in river basins is paramount for water resources management. Here, the authors analyze time series of simulated terrestrial water storage components, observed precipitation, and discharge spanning 74 yr in the Colorado River basin and relate them to climate indices that describe variability of sea surface temperature and sea level pressure in the tropical and extratropical Pacific. El Niño–Southern Oscillation (ENSO) indices in winter [January–March (JFM)] are related to winter precipitation as well as to soil moisture and discharge in the lower Colorado River basin. The low-frequency mode of the Pacific decadal oscillation (PDO) appears to be strongly correlated with deep soil moisture. During the negative PDO phase, saturated storage anomalies tend to be negative and the “amplitudes” (mean absolute anomalies) of shallow soil moisture, snow, and discharge are slightly lower compared to periods of positive PDO phases. Predicting interannual variability, therefore, strongly depends on the capability of predicting PDO regime shifts. If indeed a shift to a cool PDO phase occurred in the mid-1990s, as data suggest, the current dry conditions in the Colorado River basin may persist.

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Examination of the physical state of the soil under conventional and reduced tillage systems

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/51/2087 ◽

2013 ◽

pp. 183-186

Author(s):

Géza Tuba

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Soil Compaction ◽

Soil Layer ◽

Weather Conditions ◽

Penetration Resistance ◽

Conventional Tillage ◽

Reduced Tillage ◽

Deep Soil ◽

Tillage Systems

he effect of reduced and conventional tillage systems on soil compaction and moisture content in two years with extreme weather conditions is introduced in this paper. The investigations were carried out in a long-term soil cultivation experiment set on a heavy textured meadow chernozem soil at the Karcag Research Institute. In 2010 the amount of precipitation during the vegetation period of winter wheat was 623.3 mm, 2.2 times higher than the 50-year average, while in 2011 this value was 188.7 mm giving only 65% of the average. The examinations were made after harvest on stubbles on 4 test plots in 5 replications in the case of each tillage system. Soil compaction was characterised by penetration resistance values, while the actual soil moisture contents were determined by gravimetry. The values of penetration resistance and soil moisture content of the cultivated soil layer were better in the case of reduced tillage under extreme precipitation conditions. It could be established that regular application of deep soil loosening is essential due to the formation of the unfavourable compact soil layer under 30 cm. Conventional tillage resulted in enhanced compaction under the depth of ploughing, the penetration resistance can reach the value of 4 MPa under wet, while even 8 MPa under dry soil status.

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Effects of Long-Term Vegetation Restoration on Distribution of Deep Soil Moisture in Semi-arid Northwest of China

Journal of soil science and plant nutrition ◽

10.1007/s42729-020-00280-4 ◽

2020 ◽

Vol 20 (4) ◽

pp. 2123-2132

Author(s):

Limei Wang ◽

Aisheng Ma ◽

Hong Zhang ◽

Jianguo Zhang ◽

Qiang Dong ◽

...

Keyword(s):

Soil Moisture ◽

Vegetation Restoration ◽

Deep Soil ◽

Semi Arid

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Effects of two typical revegetation methods on soil moisture in the semi-arid Loess Plateau, China

Hydrology Research ◽

10.2166/nh.2019.011 ◽

2019 ◽

Vol 50 (5) ◽

pp. 1453-1462

Author(s):

Qian Zhao ◽

Lei Yang ◽

Xin Wang ◽

Runcheng Bi ◽

Qindi Zhang

Keyword(s):

Soil Moisture ◽

Loess Plateau ◽

Temporal Variations ◽

Chinese Loess Plateau ◽

Deep Soil ◽

Chinese Loess ◽

Soil Desiccation ◽

Native Grasslands ◽

First Choice ◽

Natural Revegetation

Abstract Understanding the effects of vegetation on soil moisture is vital to the ecosystem restoration in water-restricted areas. For this study, the effects of introduced revegetation and natural revegetation on soil water (0–1.8 m) were investigated in the Chinese Loess Plateau, which was based on an in situ vegetation removal experiment and two years of soil moisture monitoring. The results indicated that under introduced revegetation, pasture grassland had lower soil moisture but higher temporal variations over the growing season. Compared with abandoned farmlands and native grasslands under natural revegetation, pasture grasslands revealed greater negative effects on deep soil moisture (1–1.8 m), which was difficult to recover following soil desiccation. In contrast, for abandoned farmlands and native grasslands, the surface soil moisture (0–0.4 m) was mainly impacted, which was easily replenished through rainfall events. These outcomes implied that natural revegetation, rather than introduced revegetation, should be the first choice in water-limited regions toward the rehabilitation of degraded ecosystems.

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