In situ dynamics of recently allocated 14C in pasture soil and soil solution collected with Rhizon Soil Moisture Samplers

Soil Research ◽  
2005 ◽  
Vol 43 (5) ◽  
pp. 659 ◽  
Author(s):  
Bhupinderpal-Singh ◽  
M. J. Hedley ◽  
S. Saggar
Keyword(s):  
Soil Moisture ◽  
Soil Solution ◽  
Soil Surface ◽  
Pulse Labelling ◽  
Short Term ◽  
Microbial Decomposition ◽  
Different Depths ◽  
Non Destructive ◽  
Soil Interface

Information on the dynamics of recently photo-assimilated carbon (C) allocated to roots and root-derived exudates in soils is scarce and experimentally difficult to obtain. We used Rhizon Soil Moisture SamplersTM (RSMS) placed at different depths in soil (20, 40, 80, 120 mm) to monitor short-term dynamics of root and root-derived C at the root–soil interface after 14CO2 pulse-labelling of pasture cores. At the 20 mm depth, 14C activity in soil solution peaked within 2 h of 14CO2 application. The peak of 14C activity took longer to appear and slower to disappear with increased depth. Negligible amounts of 14C as soluble exudates were found in the soil solution. The pattern of initial 14C activity in soil solution, allocation of recently assimilated 14C in roots, and root mass distribution with depth were closely related to each other. This suggested that the rapid appearance of 14CO2 in soil solution is more closely linked to root respiration of recent 14C-assimilates (transferred via shoots to roots) and/or to microbial decomposition of root-released 14C-assimilates than to transfer by diffusion of atmospheric 14CO2 through open soil surface to different depths in soil. The use of RSMS was an effective, simple, and non-destructive method to monitor the dynamics of root-derived 14C by in situ sampling of soil solution.

Performance of Zero-till Bio-mulching on Different Pulses under Maize-legume Sequence

2020 ◽  
Author(s):  
J. K. Dey ◽  
B. K. Saren ◽  
B. Duary ◽  
K. Pramanik
Keyword(s):  
Soil Moisture ◽  
Water Hyacinth ◽  
Crop Residues ◽  
Low Cost ◽  
Block Design ◽  
Cropping System ◽  
Soil Surface ◽  
Paddy Straw ◽  
The Individual

Background: After harvesting of kharif crops, lack of sufficient soil moisture availability limit the cultivation of rabi crops in the Birbhum district of West Bengal. So a huge area remains fallow during the rabi season mainly because of infrastructure to harvest and to utilize the bountiful rains of the monsoon. So, agronomic measures to conserve the soil moisture are very suitable for the region because of their low cost and capability to reduce soil erosion. In this region, maize stalk are not used as fodder for animals and are usually burnt or kept outside the field. Similarly, during rainy season, there is plenty of water hyacinth and paddy straw found around cultivated areas. Retention of crop residues and weed biomass on the soil surface in combination with zero tillage initiates process that lead to improve soil quality and overall enhancement of resource use efficiency. Methods: The trials were conducted for consecutive two years (2017-18 and 2018-19) in split plot design with three main plot treatments as cropping system after Maize, viz, i) Maize-chickpea (CS1) ii) Maize-lentil (CS2) iii) Maize-lathyrus (CS3); with five sub-plot treatments as mulching i) No-mulching (Residue Removal) (M0) ii) In-situ Maize stalk mulching (M1) iii) In-situ maize stalk mulch + Water hyacinth (5 t/ha) (M2) iv) In-situ maize stalk mulch + Paddy straw (5 t/ha) (M3) v) In-situ maize stalk mulch + Water hyacinth (2.5 t/ha) + Paddy straw (2.5 t/ha) (M4) but the individual rabi crop’s data were analyzed in Randomized Block Design (RBD) as the individual crops have different growth characteristics. Result: Experiments result revealed that mulching with M3- In-situ maize stalk mulch + Paddy straw (5 t/ha) is the best practice for growing pulses under zero-till condition after Maize in Maize-legume cropping system. Growing of pulses in different cropping system under zero-till condition not only will increase the cropping intensity and production of pulses in the country but also will increase the fertility of the soil.

scholarly journals Description of the UCAR/CU Soil Moisture Product

2020 ◽  
Vol 12 (10) ◽  
pp. 1558 ◽  
Author(s):  
Clara Chew ◽  
Eric Small
Keyword(s):  
Soil Moisture ◽  
Standard Deviation ◽  
Correlation Coefficient ◽  
Random Noise ◽  
Soil Surface ◽  
Microwave Remote Sensing ◽  
Passive Microwave ◽  
Noise Component ◽  
Median Correlation

Currently, the ability to use remotely sensed soil moisture to investigate linkages between the water and energy cycles and for use in data assimilation studies is limited to passive microwave data whose temporal revisit time is 2–3 days or active microwave products with a much longer (>10 days) revisit time. This paper describes a dataset that provides soil moisture retrievals, which are gridded to 36 km, for the upper 5 cm of the soil surface at sparsely sampled 6-hour intervals for +/− 38 degrees latitude for 2017–present. Retrievals are derived from the Cyclone Global Navigation Satellite System (CYGNSS) constellation, which uses GNSS-Reflectometry to obtain L-band reflectivity observations over the Earth’s surface. The product was developed by calibrating CYGNSS reflectivity observations to soil moisture retrievals from NASA’s Soil Moisture Active Passive (SMAP) mission. Retrievals were validated against observations from 171 in-situ soil moisture probes, with a median unbiased root-mean-square error (ubRMSE) of 0.049 cm3 cm−3 (standard deviation = 0.026 cm3 cm−3) and median correlation coefficient of 0.4 (standard deviation = 0.27). For the same stations, the median ubRMSE between SMAP and in-situ observations was 0.045 cm3 cm−3 (standard deviation = 0.025 cm3 cm−3) and median correlation coefficient was 0.69 (standard deviation = 0.27). The UCAR/CU Soil Moisture Product is thus complementary to SMAP, albeit with a larger random noise component, providing soil moisture retrievals for applications that require faster revisit times than passive microwave remote sensing currently provides.

scholarly journals The International Soil Moisture Network: a data hosting facility for global in situ soil moisture measurements

2011 ◽  
Vol 8 (1) ◽  
pp. 1609-1663 ◽  
Author(s):  
W. A. Dorigo ◽  
W. Wagner ◽  
R. Hohensinn ◽  
S. Hahn ◽  
C. Paulik ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Land Surface ◽  
Water Cycle ◽  
Soil Moisture Data ◽  
The North ◽  
Time Period ◽  
Different Depths ◽  
Operational Networks

Abstract. In situ measurements of soil moisture are invaluable for calibrating and validating land surface models and satellite-based soil moisture retrievals. In addition, long-term time series of in situ soil moisture measurements themselves can reveal trends in the water cycle related to climate or land cover change. Nevertheless, on a worldwide basis the number of meteorological networks and stations measuring soil moisture, in particular on a continuous basis, is still limited and the data they provide lack standardization of technique and protocol. To overcome many of these limitations, the International Soil Moisture Network (ISMN; http://www.ipf.tuwien.ac.at/insitu) was initiated to serve as a centralized data hosting facility where globally available in situ soil moisture measurements from operational networks and validation campaigns are collected, harmonized, and made available to users. Data collecting networks share their soil moisture datasets with the ISMN on a voluntary and no-cost basis. Incoming soil moisture data are automatically transformed into common volumetric soil moisture units and checked for outliers and implausible values. Apart from soil water measurements from different depths, important metadata and meteorological variables (e.g., precipitation and soil temperature) are stored in the database. These will assist the user in correctly interpreting the soil moisture data. The database is queried through a graphical user interface while output of data selected for download is provided according to common standards for data and metadata. Currently (status January 2011), the ISMN contains data of 16 networks and more than 500 stations located in the North America, Europe, Asia, and Australia. The time period spanned by the entire database runs from 1952 until the present, although most datasets have originated during the last decade. The database is rapidly expanding, which means that both the number of stations and the time period covered by the existing stations are still growing. Hence, it will become an increasingly important resource for validating and improving satellite-derived soil moisture products and studying climate related trends. As the ISMN is animated by the scientific community itself, we invite potential networks to enrich the collection by sharing their in situ soil moisture data.

The effects of soil moisture and planting depth on emergence and seedling morphology of Astrebla lappacea (Lindl.) Domin

1990 ◽  
Vol 41 (2) ◽  
pp. 367 ◽  
Author(s):  
FJ Lambert ◽  
M Bower ◽  
RDB Whalley ◽  
AC Andrews ◽  
WD Bellotti
Keyword(s):  
Soil Moisture ◽  
Soil Surface ◽  
Field Capacity ◽  
Seedling Morphology ◽  
Planting Depth ◽  
Sowing Depth ◽  
Delayed Emergence ◽  
Different Depths ◽  
Glasshouse Experiment ◽  
Secondary Roots

The effect of various wet and dry day sequences on emergence of seedlings of Astrebla lappacea (Mitchell grass) from both spikelets and caryopses was studied in a glasshouse experiment. Three wet days were required to obtain maximum emergence while periods of 2-4 dry days delayed emergence but did not affect final emergence, provided moisture was re-supplied. The soil reached a water potential of -6 MPa after 2 dry days, which was sufficient to prevent the germination processes from proceeding. Maximum emergence was reached in 8 days for the caryopses and 10 days for the spikelets, so long as each wet day in the period was separated by no more than 2 dry days. At least 40% of the A. lappacea caryopses sown emerged as seedlings from a sowing depth of 60 mm in a sand medium, and from a sowing depth of 45 mm in a clay medium. The maximum depth from which seedlings emerged was 60 mm in the clay medium, and from 80 mm in the sand medium. Both media were maintained at 90% of field capacity. The emergence from single caryopses in sand was greater and more rapid than from clay. Planting depth significantly affected the length of the subcoleoptile internode of A. lappacea during a glasshouse experiment. All seedlings initiated their secondary roots at the soil surface irrespective of sowing depth. Increasing sowing depth retarded the early development of the secondary root system, but by week five, there were no significant differences between the dry weights of secondary roots from plants sown at different depths.

scholarly journals The International Soil Moisture Network: a data hosting facility for global in situ soil moisture measurements

2011 ◽  
Vol 15 (5) ◽  
pp. 1675-1698 ◽  
Author(s):  
W. A. Dorigo ◽  
W. Wagner ◽  
R. Hohensinn ◽  
S. Hahn ◽  
C. Paulik ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Land Surface ◽  
Water Cycle ◽  
Soil Moisture Data ◽  
Time Period ◽  
Surface Models ◽  
Different Depths ◽  
Operational Networks

Abstract. In situ measurements of soil moisture are invaluable for calibrating and validating land surface models and satellite-based soil moisture retrievals. In addition, long-term time series of in situ soil moisture measurements themselves can reveal trends in the water cycle related to climate or land cover change. Nevertheless, on a worldwide basis the number of meteorological networks and stations measuring soil moisture, in particular on a continuous basis, is still limited and the data they provide lack standardization of technique and protocol. To overcome many of these limitations, the International Soil Moisture Network (ISMN; http://www.ipf.tuwien.ac.at/insitu) was initiated to serve as a centralized data hosting facility where globally available in situ soil moisture measurements from operational networks and validation campaigns are collected, harmonized, and made available to users. Data collecting networks share their soil moisture datasets with the ISMN on a voluntary and no-cost basis. Incoming soil moisture data are automatically transformed into common volumetric soil moisture units and checked for outliers and implausible values. Apart from soil water measurements from different depths, important metadata and meteorological variables (e.g., precipitation and soil temperature) are stored in the database. These will assist the user in correctly interpreting the soil moisture data. The database is queried through a graphical user interface while output of data selected for download is provided according to common standards for data and metadata. Currently (status May 2011), the ISMN contains data of 19 networks and more than 500 stations located in North America, Europe, Asia, and Australia. The time period spanned by the entire database runs from 1952 until the present, although most datasets have originated during the last decade. The database is rapidly expanding, which means that both the number of stations and the time period covered by the existing stations are still growing. Hence, it will become an increasingly important resource for validating and improving satellite-derived soil moisture products and studying climate related trends. As the ISMN is animated by the scientific community itself, we invite potential networks to enrich the collection by sharing their in situ soil moisture data.

scholarly journals Soil solkution and methods of its investigation

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Vladimir V. Popov
Keyword(s):  
Soil Moisture ◽  
Liquid Phase ◽  
Soil Solution ◽  
Water Extracts ◽  
Advantages And Disadvantages

The article describes main categories of soil moisture (hydroscopic, capillary, and gravitational, providing their brief characteristics, and discusses the main advantages and disadvantages of the methods that are currently used to study the liquid phase of soils, such as using water extracts and saturated pastes, displacing soil solution with a substitute liquid, pressing, centrifugation, lysimetry and studying soil liquid phase in situ.

scholarly journals Assessment of Remotely Sensed and Modelled Soil Moisture Data Products in the U.S. Southern Great Plains

2020 ◽  
Vol 12 (12) ◽  
pp. 2030
Author(s):  
Bo Jiang ◽  
Hongbo Su ◽  
Kai Liu ◽  
Shaohui Chen
Keyword(s):  
Soil Moisture ◽  
Great Plains ◽  
Land Surface ◽  
European Space Agency ◽  
Remotely Sensed ◽  
The Other ◽  
Short Term ◽  
Southern Great Plains ◽  
The U.S

Soil moisture (SM) plays a crucial role in the water and energy flux exchange between the atmosphere and the land surface. Remote sensing and modeling are two main approaches to obtain SM over a large-scale area. However, there is a big difference between them due to algorithm, spatial-temporal resolution, observation depth and measurement uncertainties. In this study, an assessment of the comparison of two state-of-the-art remotely sensed SM products, Soil Moisture Active Passive (SMAP) and European Space Agency Climate Change Initiative (ESACCI), and one land surface modeled dataset from the North American Land Data Assimilation System project phase 2 (NLDAS-2), were conducted using 17 permanent SM observation sites located in the Southern Great Plains (SGP) in the U.S. We first compared the daily mean SM of three products with in-situ measurements; then, we decompose the raw time series into a short-term seasonal part and anomaly by using a moving smooth window (35 days). In addition, we calculate the daily spatial difference between three products based on in-situ data and assess their temporal evolution. The results demonstrate that (1) in terms of temporal correlation R, the SMAP (R = 0.78) outperforms ESACCI (R = 0.62) and NLDAS-2 (R = 0.72) overall; (2) for the seasonal component, the correlation R of SMAP still outperforms the other two products, and the correlation R of ESACCI and NLDAS-2 have not improved like the SMAP; as for anomaly, there is no difference between the remotely sensed and modeling data, which implies the potential for the satellite products to capture the variations of short-term rainfall events; (3) the distribution pattern of spatial bias is different between the three products. For NLDAS-2, it is strongly dependent on precipitation; meanwhile, the spatial distribution of bias represents less correlation with the precipitation for two remotely sensed products, especially for the SMAP. Overall, the SMAP was superior to the other two products, especially when the SM was of low value. The difference between the remotely sensed and modeling products with respect to the vegetation type might be an important reason for the errors.

scholarly journals Vegetation Optical Depth and Soil Moisture Retrieved from L-Band Radiometry over the Growth Cycle of a Winter Wheat

2018 ◽  
Vol 10 (10) ◽  
pp. 1637 ◽  
Author(s):  
Thomas Meyer ◽  
Lutz Weihermüller ◽  
Harry Vereecken ◽  
François Jonard
Keyword(s):  
Soil Moisture ◽  
Winter Wheat ◽  
Optical Depth ◽  
Incidence Angle ◽  
Soil Surface ◽  
Growing Season ◽  
Area Index ◽  
Vegetation Height ◽  
L Band

L-band radiometer measurements were performed at the Selhausen remote sensing field laboratory (Germany) over the entire growing season of a winter wheat stand. L-band microwave observations were collected over two different footprints within a homogenous winter wheat stand in order to disentangle the emissions originating from the soil and from the vegetation. Based on brightness temperature (TB) measurements performed over an area consisting of a soil surface covered by a reflector (i.e., to block the radiation from the soil surface), vegetation optical depth (τ) information was retrieved using the tau-omega (τ-ω) radiative transfer model. The retrieved τ appeared to be clearly polarization dependent, with lower values for horizontal (H) and higher values for vertical (V) polarization. Additionally, a strong dependency of τ on incidence angle for the V polarization was observed. Furthermore, τ indicated a bell-shaped temporal evolution, with lowest values during the tillering and senescence stages, and highest values during flowering of the wheat plants. The latter corresponded to the highest amounts of vegetation water content (VWC) and largest leaf area index (LAI). To show that the time, polarization, and angle dependence is also highly dependent on the observed vegetation species, white mustard was grown during a short experiment, and radiometer measurements were performed using the same experimental setup. These results showed that the mustard canopy is more isotropic compared to the wheat vegetation (i.e., the τ parameter is less dependent on incidence angle and polarization). In a next step, the relationship between τ and in situ measured vegetation properties (VWC, LAI, total of aboveground vegetation biomass, and vegetation height) was investigated, showing a strong correlation between τ over the entire growing season and the VWC as well as between τ and LAI. Finally, the soil moisture was retrieved from TB observations over a second plot without a reflector on the ground. The retrievals were significantly improved compared to in situ measurements by using the time, polarization, and angle dependent τ as a priori information. This improvement can be explained by the better representation of the vegetation layer effect on the measured TB.

Short-term dynamics of abiotic and biotic soil 13CO2 effluxes after in situ 13CO2 pulse labelling of a boreal pine forest

2009 ◽  
Vol 183 (2) ◽  
pp. 349-357 ◽  
Author(s):  
Jens-Arne Subke ◽  
Harry W. Vallack ◽  
Tord Magnusson ◽  
Sonja G. Keel ◽  
Daniel B. Metcalfe ◽  
...  
Keyword(s):  
Pine Forest ◽  
Pulse Labelling ◽  
Short Term

MEASUREMENT OF CO2 EVOLVED FROM ORGANIC SOIL AT DIFFERENT DEPTHS IN SITU

1981 ◽  
Vol 61 (1) ◽  
pp. 137-144 ◽  
Author(s):  
J. A. CAMPBELL ◽  
L. FRASCARELLI
Keyword(s):  
Soil Column ◽  
Soil Surface ◽  
Organic Soil ◽  
Organic Soils ◽  
Concentration Profiles ◽  
Undisturbed Soil ◽  
Surface Evolution ◽  
Different Depths ◽  
A New Technique

A new technique for measuring CO2 evolved from organic soil at different depths in situ was used to monitor CO2 evolution in four experimental sites in southwestern Quebec and in an undisturbed soil column in the laboratory. The technique can be used in conjunction with in situ measurements of surface evolution of CO2, which are used as indicators of total subsidence by oxidation. Subsurface measurements of CO2 evolution provide more detailed estimates of where oxidation is occurring within the profile in organic soils. It also provides a simpler, more direct way of measuring CO2 fluxes below the soil surface than modelling from concentration profiles.

Sign in / Sign up

Export Citation Format

Share Document