The agroecological soil quality assessment of Central-Russian upland and Oka-Don lowland of Russia.

2020 ◽  
Author(s):  
Nikolai Lozbenev ◽  
Daniil Kozlov
Keyword(s):  
Soil Moisture ◽  
Spatial Structure ◽  
Spatial Heterogeneity ◽  
Soil Water ◽  
Soil Quality ◽  
Soil Texture ◽  
Soil Layer ◽  
Water Capacity ◽  
Central Russian Upland ◽  
Moisture Conditions

<p>The modern Russian agroecological landscape evaluation is based on identification of areas with specific hydrology, soil and terrain constraints to crop, that are named as agroecological groups of lands. Soil quality of the lands is characterized by a combination of conditions ensuring sustainable crop yields and determining the ecological functions and stability of agrolandscapes. The main differences in soil quality in the forest-steppe of the East European Plain are due to soil erosion and precipitation redistribution by the topography elements. If the erosion processes are comprehensively studied by the world scientific community, then the influence of differences in soil moisture reserves, its spatial heterogeneity and potential impact on the crops productivity is not sufficiently considered by Russian specialists. In this regard, large-scale studies were carried out at two key areas: the Central Russian Upland (Kursk region) and the Oka-Don Lowland (Tambov region). The studies included conventional mapping with identification of agroecological groups of lands and their quality assessment using GIS and statistical analysis. To determine the spatial heterogeneity of the moisture conditions, the SIMWE simulation model was applied. This model calculates the precipitation redistribution by the topography elements using digital elevation model and several input parameters. It was find, that the territory of the Central Russian Upland is characterized by normal moisture conditions, leaching water regime, silty-loamy soil texture. Redistribution of precipitation occurs without delay, as a result of which most of the territory does not experience overmoistening and the soils are highly productive with moisture reserves in the top meter layer up to 150 mm. The spatial structure of soil water capacity in a meter soil layer was determined by the regression analysis method of the measured soil moisture and calculated runoff using the SIMWE model. It was determined that the intra-landscape variation of moisture capacity as an indicator of soil quality for agriculture is associated with the topography of the interfluves and the erosion. The second key area, the Oka-Don Lowland, is characterized by a lowland topography and clay soil texture, and excess of moisture in soils in almost all years. Several agroecological groups of lands with significantly different in soil water capacity. To determine the spatial structure of soil water capacity, the SIMWE model was also used, that showed a high intra-landscape soils diversity, that is due to a flat topography of interfluve with lots of depressions. The soils of drained interfluves with a short-term overmoistening and a groundwater level below 6 meters are of the highest quality. In addition, hydromorphic lands with groundwater above 6 meters and average annual moisture reserves in top meter soil layer up to 300 mm are distinguished. They occupy about 72% of the total area of ​​the key site. Such lands are suitable for cultivation of perennial grasses, winter wheat, soybeans, sunflowers and others.</p><p>This study is supported by Russian Foundation for Basic Research, grant №19-29-05277.</p>

scholarly journals Root Response to Soil Water Status via Interaction of Crop Genotype and Environment

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 708
Author(s):  
Phanthasin Khanthavong ◽  
Shin Yabuta ◽  
Hidetoshi Asai ◽  
Md. Amzad Hossain ◽  
Isao Akagi ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Root Distribution ◽  
Water Status ◽  
Soil Layer ◽  
Shoot Biomass ◽  
Soil Conditions ◽  
Crop Adaptation ◽  
Soil Moisture Status ◽  
Root Distributions

Flooding and drought are major causes of reductions in crop productivity. Root distribution indicates crop adaptation to water stress. Therefore, we aimed to identify crop roots response based on root distribution under various soil conditions. The root distribution of four crops—maize, millet, sorghum, and rice—was evaluated under continuous soil waterlogging (CSW), moderate soil moisture (MSM), and gradual soil drying (GSD) conditions. Roots extended largely to the shallow soil layer in CSW and grew longer to the deeper soil layer in GSD in maize and sorghum. GSD tended to promote the root and shoot biomass across soil moisture status regardless of the crop species. The change of specific root density in rice and millet was small compared with maize and sorghum between different soil moisture statuses. Crop response in shoot and root biomass to various soil moisture status was highest in maize and lowest in rice among the tested crops as per the regression coefficient. Thus, we describe different root distributions associated with crop plasticity, which signify root spread changes, depending on soil water conditions in different crop genotypes as well as root distributions that vary depending on crop adaptation from anaerobic to aerobic conditions.

A regionally explicit, global SWI calibration based on ISMN observations

2021 ◽  
Author(s):  
Manolis G. Grillakis
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Large Scale ◽  
Root Zone ◽  
Soil Depth ◽  
European Space Agency ◽  
Soil Layer ◽  
Added Value ◽  
Water Index ◽  
Soil Moisture Data

<p>Remote sensing has proven to be an irreplaceable tool for monitoring soil moisture. The European Space Agency (ESA), through the Climate Change Initiative (CCI), has provided one of the most substantial contributions in the soil water monitoring, with almost 4 decades of global satellite derived and homogenized soil moisture data for the uppermost soil layer. Yet, due to the inherent limitations of many of the remote sensors, only a limited soil depth can be monitored. To enable the assessment of the deeper soil layer moisture from surface remotely sensed products, the Soil Water Index (SWI) has been established as a convolutive transformation of the surface soil moisture estimation, under the assumption of uniform hydraulic conductivity and the absence of transpiration. The SWI uses a single calibration parameter, the T-value, to modify its response over time.</p><p>Here the Soil Water Index (SWI) is calibrated using ESA CCI soil moisture against in situ observations from the International Soil Moisture Network and then use Artificial Neural Networks (ANNs) to find the best physical soil, climate, and vegetation descriptors at a global scale to regionalize the calibration of the T-value. The calibration is then used to assess a root zone related soil moisture for the period 2001 – 2018.</p><p>The results are compared against the European Centre for Medium-Range Weather Forecasts, ERA5 Land reanalysis soil moisture dataset, showing a good agreement, mainly over mid-latitudes. The results indicate that there is added value to the results of the machine learning calibration, comparing to the uniform T-value. This work contributes to the exploitation of ESA CCI soil moisture data, while the produced data can support large scale soil moisture related studies.</p>

No evidence that earthworms increase soil greenhouse gas emissions (CO2 and N2O) in the presence of plants and soil-moisture fluctuations

2021 ◽  
Author(s):  
Pierre Ganault ◽  
Johanne Nahmani ◽  
Yvan Capowiez ◽  
Isabelle Bertrand ◽  
Bruno Buatois ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Greenhouse Gases ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Soil Water ◽  
Water Status ◽  
Soil Layer ◽  
Agricultural Practices ◽  
Biodiversity Loss ◽  
Gas Emissions

<p>Accelerating climate change and biodiversity loss calls for agricultural practices that can sustain productivity with lower greenhouse gas emissions while maintaining biodiversity. Biodiversity-friendly agricultural practices have been shown to increase earthworm populations, but according to a recent meta-analyses, earthworms could increase soil CO<sub>2</sub> and N<sub>2</sub>O emissions by 33 and 42%, respectively. However, to date, many studies reported idiosyncratic and inconsistent effects of earthworms on greenhouse gases, indicating that the underlying mechanisms are not fully understood. Here we report the effects of earthworms (anecic, endogeic and their combination) with or without plants on CO<sub>2</sub> and N<sub>2</sub>O emissions in the presence of soil-moisture fluctuations from a mesocosms experiment. The experimental set-up was explicitly designed to account for the engineering effect of earthworms (i.e. burrowing) and investigate the consequences on soil macroporosity, soil water dynamic, and microbial activity. We found that plants reduced N<sub>2</sub>O emissions by 19.80% and that relative to the no earthworm control, the cumulative N<sub>2</sub>O emissions were 17.04, 34.59 and 44.81% lower in the anecic, both species and endogeic species, respectively. CO<sub>2</sub> emissions were not significantly affected by the plants or earthworms but depended on the interaction between earthworms and soil water content, an interaction that was also observed for the N<sub>2</sub>O emissions. Soil porosity variables measured by X-ray tomography suggest that the earthworm effects on CO<sub>2</sub> and N<sub>2</sub>O emissions were mediated by the burrowing patterns affecting the soil aeration and water status. N<sub>2</sub>O emissions decreased with the volume occupied by macropores in the deeper soil layer, whereas CO<sub>2</sub> emissions decreased with the macropore volume in the top soil layer. This study suggests that experimental setups without plants and in containers where the earthworm soil engineering effects via burrowing and casting on soil water status are minimized may be responsible, at least in part, for the reported positive earthworm effects on greenhouse gases.</p>

An assessment of soil moisture in the MARINE flash flood model using in situ measurements, reanalysis and satellite derived estimates

2020 ◽  
Author(s):  
Judith Eeckman ◽  
Hélène Roux ◽  
Bertrand Bonan ◽  
Clément Albergel ◽  
Audrey Douniot
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Model Calibration ◽  
Flash Flood ◽  
Soil Column ◽  
Subsurface Flow ◽  
Soil Layer ◽  
Observation Network

<p>The representation of soil moisture is a key factor for the simulation of flash flood in the Mediterranean region. The MARINE hydrological model is a distributed model dedicaded to flash flood simulation. Recent developments of the MARINE model lead to an improvement of the subsurface flow representation : on the one hand, the transfers through the subsurface take place in a homogeneous soil column based on the volumic soil water content instead of the water height. On the other hand, the soil column is divided into two layers, which represent respectively the upper soil layer and the deep weathered rocks. The aim of this work is to assess the performances of these new representations of the subsurface flow with respect to the soil saturation dynamics during flash flood events. The performances of the model are estimated with respect to three soil moisture products: i) the gridded soil moisture product provided by the LDAS-Monde assimilation chain. LDAS-Monde is based on the ISBA-a-gs land surface model and integrates high resolution spatial remote sensing data from the Copernicus Global Land Service for vegetation through data assimilation; ii) the upper soil moisture measurements taken from the SMOSMANIA observation network ; iii) The satellite derived surface soil moisture data from Sentinel1. The case study is led over two french mediterranean catchments impacted by flash flood events over the 2017-2019 period and where one SMOSMANIA station is available. Additionnal tests for the initialisation of MARINE water content for the two soil layers are assessed. Results show first that the dynamic of the soil moisture both provided by LDAS-Monde and simulated for the upper soil layer in MARINE are locally consistent with the SMOSMANIA observations. Secondly, the use of soil water content instead of water height to describe lateral flows in MARINE is cleary more relevant with respect to both LDAS-Monde simulations and SMOSMANIA stations. The dynamic of the deep layer moisture content also appears to be consistent with the LDAS-Monde product for deeper layers. However, the bias on these values strongly rely on the calibration of the new two-layers model. The opportunity of improving the two-layers model calibration is then discussed. Finally, the impact of the soil water content initialisation is shown to be significant mainly during the flood rising, and also to be dependent on the model calibration. In conclusion, the new developments presented for the representation of subsurface flow in the MARINE model appear to enhance the soil moisture simulation during flash floods, with respect to both the LDAS-Monde product and the SMOSMANIA observation network.</p>

scholarly journals Effects of antecedent soil moisture on runoff modeling in small semiarid watersheds of southeastern Arizona

2011 ◽  
Vol 15 (10) ◽  
pp. 3171-3179 ◽  
Author(s):  
Y. Zhang ◽  
H. Wei ◽  
M. A. Nearing
Keyword(s):  
Soil Moisture ◽  
Standard Deviation ◽  
Soil Layer ◽  
Arid Environment ◽  
Storm Events ◽  
Runoff Generation ◽  
Antecedent Soil Moisture ◽  
Small Watersheds ◽  
Runoff Modeling ◽  
Moisture Conditions

Abstract. This study presents unique data on the effects of antecedent soil moisture on runoff generation in a semi-arid environment, with implications for process-based modeling of runoff. The data were collected from four small watersheds measured continuously from 2002 through 2010 in an environment where evapo-transpiration approaches 100% of the infiltrated water on the hillslopes. Storm events were generally intense and of short duration, and antecedent volumetric moisture conditions were dry, with an average in the upper 5 cm soil layer over the nine year period of 8% and a standard deviation of 3%. Sensitivity analysis of the model showed an average of 0.05 mm change in runoff for each 1% change in soil moisture, indicating an approximate 0.15 mm average variation in runoff accounted for by the 3% standard deviation of measured antecedent soil moisture. This compared to a standard deviation of 4.7 mm in the runoff depths for the measured events. Thus the low variability of soil moisture in this environment accounts for a relative lack of importance of storm antecedent soil moisture for modeling the runoff. Runoff characteristics simulated with a nine year average of antecedent soil moisture were statistically identical to those simulated with measured antecedent soil moisture, indicating that long term average antecedent soil moisture could be used as a substitute for measured antecedent soil moisture for runoff modeling of these watersheds. We also found no significant correlations between measured runoff ratio and antecedent soil moisture in any of the four watersheds.

scholarly journals SOIL pH AND MOISTURE EFFECTS ON VEGETABLE AMARANTH PRODUCTION

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 647e-647
Author(s):  
Bharat P. Singh ◽  
Wayne F. Whitehead
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Soil Ph ◽  
Water Levels ◽  
Plant Parts ◽  
Moisture Effects ◽  
Wide Range ◽  
Significant Difference ◽  
Plant Grown ◽  
Moisture Conditions

The effect of soil moisture and pH levels on the vegetative growth of amaranth were studied in the greenhouse during 1990-91. Three soil pH levels: 4.5, 5.3, and 6.4 and four soil water levels: 3, 6, 12 and 18% (w/w) comprised the treatments of the two studies. The plants grown in pH 6.4 were significantly taller and had greater leaf area than plants grown in pH 5.3 or 4.7 soil. There was a significant decrease in all above ground plant parts with each increase in soil acidity. The top fresh weight of plants grown in 5.6 and 4.7 pH soil were 27% and 73% lower, respectively, than plant grown in 6.4 pH soil. Plant grown in 3% soil water had significantly lower leaf, stem and root fresh weights than other soil water levels. There was no significant difference in the performance of plants grown in 6, 12 or 18% soil water, suggesting that amaranth plant is adapted to a wide range of soil moisture conditions.

scholarly journals Using StorAge Selection functions to quantify ecohydrological controls on the time-variant age of evapotranspiration, soil water, and recharge

2018 ◽  
Author(s):  
Aaron A. Smith ◽  
Doerthe Tetzlaff ◽  
Chris Soulsby
Keyword(s):  
Soil Moisture ◽  
Surface Water ◽  
Soil Water ◽  
Water Uptake ◽  
Root Water Uptake ◽  
Soil Evaporation ◽  
Root Uptake ◽  
Water Fluxes ◽  
Near Surface ◽  
Moisture Conditions

Abstract. Quantifying ecohydrological controls on soil water availability is essential to understand temporal variations in catchment storage. Soil water is subject to numerous time-variable fluxes (evaporation, root-uptake, and recharge), each with different water ages which in turn affect the age of water in storage. Here, we adapt StorAge Selection (SAS) function theory to investigate water flow in soils and identify soil evaporation and root-water uptake sources from depth. We use this to quantify the effects of soil-vegetation interactions on the inter-relationships between water fluxes, storage, and age. The novel modification of the SAS function framework is tested against empirical data from two contrasting soil-vegetation units in the Scottish Highlands; these are characterised by significant preferential flow, transporting younger water through the soil during high soil moisture conditions. Dominant young water fluxes, along with relatively low rainfall intensities, explain relatively stable soil water ages through time and with depth. Soil evaporation sources were more time-invariant with high preference for near-surface water, independent of soil moisture conditions, and resulting in soil evaporation water ages similar to near-surface soil waters (mean age: 50–65 days). Sources of root-water uptake were more variable: preferential near-surface water uptake occurred in wet conditions, with a deeper root-uptake source during dry soil conditions, which resulted in more variable water ages of transpiration (mean age: 56–79 days). The simple model structure provides a parsimonious means of constraining the water age of multiple fluxes from the upper part of the critical zone during time-varying conditions improving our understanding of vegetation influences on catchment scale water fluxes.

scholarly journals Soil-water physical attributes under different managements systems in the humid tropics in Maranhão

2020 ◽  
Vol 13 (9) ◽  
pp. 38
Author(s):  
J. B. Martins Filho ◽  
K. C. Cunha Meneses ◽  
A. L. Brito Filho ◽  
C. E. L. Feitosa ◽  
M. F. Farias
Keyword(s):  
Soil Moisture ◽  
Physical Properties ◽  
Soil Water ◽  
Total Porosity ◽  
Native Forest ◽  
Water Capacity ◽  
Total Soil ◽  
Randomized Design ◽  
Vertical Hydraulic Conductivity ◽  
Physical Attributes

This study was conducted to evaluate the physical properties modifications of an Oxisol under different conditions of use and management. The research was conducted at Fazenda Sítio Novo and in native forest area, respectively in the municipalities of São Benedito do Rio Preto/MA and Chapadinha/MA. The research followed a completely randomized design with 3 treatments and 4 replications, with the following uses and management: no-tillage (PD); conventional planting (CP) and native forest (MN). The following physical properties were analyzed: bulk density, porosity and soil moisture and penetration resistance at depths of 0.0-0.20 m and 0.20-0.40 m. The water properties analyzed were: basic infiltration velocity, total soil water capacity and vertical hydraulic conductivity. The soil presented higher density and low conservation of moisture in PD and PC. Native forest presented higher total porosity and higher conservation of soil moisture. Total soil water capacity was higher in MN (39.89 mm) followed by PC (25.33 mm) and PD (18.84 mm). The uses and management employed in the soils analyzed on the farm reflect the degradation of the physical properties of the soil in relation to native forest. 

Temporal fluctuations in soil water repellency following wildfire in chaparral steeplands, southern California

2005 ◽  
Vol 14 (4) ◽  
pp. 439 ◽  
Author(s):  
K. R. Hubbert ◽  
V. Oriol
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Water Repellency ◽  
Weather Conditions ◽  
Antecedent Rainfall ◽  
Soil Water Repellency ◽  
Soil Wetness ◽  
Moisture Conditions ◽  
East West ◽  
Seasonal Weather

Soil water repellency is particularly common in unburned chaparral, and its degree and duration can be influenced by seasonal weather conditions. Water repellency tends to increase in dry soils, while it decreases or vanishes following precipitation or extended periods of soil moisture. The 15 426 ha Williams Fire provided an opportunity to investigate post-fire fluctuations in water repellency over a 1-year period. Soil water repellency was measured at the surface, and at 2-cm and 4-cm depths along six east–west-positioned transects located within the chaparral-dominated San Dimas Experimental Forest. During the winter and spring, seasonal variation in the degree of surface water repellency appeared to be inversely proportional to antecedent rainfall and soil moisture conditions. Precipitation through December reduced the proportion of surface ‘moderate or higher repellency’ from 49 to 4% as soil wetness increased to 12%. Throughout the summer, soil wetness remained below 2%; however, surface soils remained ‘wettable’, with the proportion of surface ‘moderate or higher repellency’ never returning to the early post-fire amount of 47%. Interestingly, at the 4-cm depth, the proportion of ‘moderate or higher repellency’ remained at levels >25% throughout the summer dry season.

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