scholarly journals Soil moisture and matric potential – An open field comparison ofsensor systems

2019 ◽  
Author(s):  
Conrad Jackisch ◽  
Kai Germer ◽  
Thomas Graeff ◽  
Ines Andrä ◽  
Katrin Schulz ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Best Practice ◽  
Calibration Procedure ◽  
Sensor Systems ◽  
State Variables ◽  
State Monitoring ◽  
Matric Potential ◽  
Growing Period ◽  
Measuring Campaign ◽  
Reference Measurements

Abstract. Soil water content and matric potential are central hydrological state variables. A large variety of automated probesand sensor systems for state monitoring exists and is frequently applied. Most studies solely rely on the calibration by themanufacturers. Until now, there is no commonly agreed calibration procedure. Moreover, several opinions about the capabilitiesand reliabilities of specific sensing methods or sensor systems exist and compete. A consortium of several institutions conducted a comparison study of currently available sensor systems for soil water5content and matric potential under field conditions. All probes have been installed in 0.2 m depth below surface following best practice procedure. We present the setup and the recorded data of 58 probes of 15 different systems measuring soil moisture and further 50 probes of 14 different systems for matric potential. The measuring campaign was conducted in the growing period of 2016. The monitoring data, results from pedophysical analyses of the soil and laboratory reference measurements for calibration are published in Jackisch et al. (2018, https://doi.org/10.1594/PANGAEA.892319).

scholarly journals Soil moisture and matric potential – an open field comparison of sensor systems

2020 ◽  
Vol 12 (1) ◽  
pp. 683-697 ◽  
Author(s):  
Conrad Jackisch ◽  
Kai Germer ◽  
Thomas Graeff ◽  
Ines Andrä ◽  
Katrin Schulz ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Best Practice ◽  
Calibration Procedure ◽  
Sensor Systems ◽  
State Variables ◽  
Matric Potential ◽  
Cross Correlation Analysis

Abstract. Soil water content and matric potential are central hydrological state variables. A large variety of automated probes and sensor systems for state monitoring exist and are frequently applied. Most applications solely rely on the calibration by the manufacturers. Until now, there has been no commonly agreed-upon calibration procedure. Moreover, several opinions about the capabilities and reliabilities of specific sensing methods or sensor systems exist and compete. A consortium of several institutions conducted a comparison study of currently available sensor systems for soil water content and matric potential under field conditions. All probes were installed at 0.2 m b.s. (metres below surface), following best-practice procedures. We present the set-up and the recorded data of 58 probes of 15 different systems measuring soil moisture and 50 further probes of 14 different systems for matric potential. We briefly discuss the limited coherence of the measurements in a cross-correlation analysis. The measuring campaign was conducted during the growing period of 2016. The monitoring data, results from pedophysical analyses of the soil and laboratory reference measurements for calibration are published in Jackisch et al. (2018, https://doi.org/10.1594/PANGAEA.892319).

scholarly journals Influence of pH and Matric Potential on Germination of Cephalosporium gramineum Conidia

Plant Disease ◽  
1998 ◽  
Vol 82 (9) ◽  
pp. 975-978 ◽  
Author(s):  
Cynthia A. Blank ◽  
Timothy D. Murray
Keyword(s):  
Soil Moisture ◽  
Soil Ph ◽  
Significant Influence ◽  
Phosphate Buffer ◽  
Mineral Salts ◽  
Matric Potential ◽  
High Soil Moisture ◽  
Soil Fungistasis ◽  
Cephalosporium Gramineum ◽  
Influence Of Ph

Germination of Cephalosporium gramineum conidia in soil was up to twofold greater at -0.064 MPa than at -0.037 and -0.007 MPa when incubated at 5°C for 2 days. Soil pH from 4.7 to 7.5 did not have a significant influence on germination of conidia and the interaction between soil pH and matric potential on germination was not significant. Soil fungistasis, which was previously observed for conidia of C. gramineum, was not observed in these studies. Germination of conidia on mineral salts agar containing phosphate buffer was significantly less at pH 4.5 than at 5.5, 6.5, or 7.5 at 5°C in one of two experiments; however, pH had no influence on germination at 10 or 20°C in two experiments. Although Cephalosporium stripe is more severe under conditions of high soil moisture and low soil pH, increased germination of conidia in response to these factors does not explain the observed increase in disease.

scholarly journals Non-stationarity of electrical resistivity and soil moisture relationship in heterogeneous soil system: a case study

2015 ◽  
Vol 2 (2) ◽  
pp. 955-994
Author(s):  
D. Michot ◽  
Z. Thomas ◽  
I. Adam
Keyword(s):  
Electrical Resistivity ◽  
Soil Moisture ◽  
Root Zone ◽  
Spatial Scales ◽  
Geophysical Methods ◽  
Matric Potential ◽  
Soil System ◽  
Retention Curve ◽  
Heterogeneous Soil ◽  
Change In Mean

Abstract. Root uptake is the most decisive key in water transfer involving soil and vegetation. It depends on water availability which can be evaluated by punctual measurements. Additionally, surface geophysical methods such as Electrical Resistivity Tomography (ERT) provide larger spatial scales. This paper focuses on investigating temporal and spatial soil moisture changes, along a toposequence crossed by a hedgerow, using ERT and punctual measurements. 10 ERT were performed over the studied period for a 28 m long transect and compared to matric potential and groundwater level measurements. Soil Volumetric Water Content (VWC) was predicted using two methods (i) from ER using Waxman and Smits model (ii) and from matric potential using experimental retention curve fitted by Van Genuchten model. Probability Density Functions (Pdfs) of our set of data show that the largest change, in mean values of ER as well as matric potential, was observed in the topsoil layer. We then analyzed the consistency between ER and punctual measurements in this layer by extracting the arrays in the junction between ER grids and punctual measurements. Pdfs of ER maps at each monitoring time (from T01 to T10) were also calculated to select the more contrasted distributions corresponding to the wettest (T06) and driest states (T10). Results of ER were consistent with matric potential measurements with two different behaviors for locations inside and outside the root zone. A strong correlation (r = 0.9) between VWC values from Waxman and Smits model and those obtained from retention curve was observed outside the root zone. The heterogeneous soil system inside the root zone shows a different pattern in this relationship. The shift in the relationship between ER and soil moisture for the locations outside and inside the root zone highlights the non-stationarity in heterogeneous soil system. Such systems were actually related to the high hedgerow root density and also to a particular topographical context (ditch and bank) which is encountered in Brittany and over north-west of Europe.

scholarly journals Smart & Green: An Internet-of-Things Framework for Smart Irrigation

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 190 ◽  
Author(s):  
Nidia G. S. Campos ◽  
Atslands R. Rocha ◽  
Rubens Gondim ◽  
Ticiana L. Coelho da Silva ◽  
Danielo G. Gomes
Keyword(s):  
Soil Moisture ◽  
Irrigation Management ◽  
Management Plan ◽  
Matric Potential ◽  
Outlier Removal ◽  
Temporal Window ◽  
Soil Moisture Sensors ◽  
Management Scheme ◽  
Smart Agriculture ◽  
Different Sources

Irrigation is one of the most water-intensive agricultural activities in the world, which has been increasing over time. Choosing an optimal irrigation management plan depends on having available data in the monitoring field. A smart agriculture system gathers data from several sources; however, the data are not guaranteed to be free of discrepant values (i.e., outliers), which can damage the precision of irrigation management. Furthermore, data from different sources must fit into the same temporal window required for irrigation management and the data preprocessing must be dynamic and automatic to benefit users of the irrigation management plan. In this paper, we propose the Smart&Green framework to offer services for smart irrigation, such as data monitoring, preprocessing, fusion, synchronization, storage, and irrigation management enriched by the prediction of soil moisture. Outlier removal techniques allow for more precise irrigation management. For fields without soil moisture sensors, the prediction model estimates the matric potential using weather, crop, and irrigation information. We apply the predicted matric potential approach to the Van Genutchen model to determine the moisture used in an irrigation management scheme. We can save, on average, between 56.4% and 90% of the irrigation water needed by applying the Zscore, MZscore and Chauvenet outlier removal techniques to the predicted data.

scholarly journals The Modification of Difference Vegetation Index (DVI) in middle and late growing period of winter wheat and its application in soil moisture inversion

2019 ◽  
Vol 131 ◽  
pp. 01098
Author(s):  
Zhang Hong-wei ◽  
Huai-liang Chen ◽  
Fei-na Zha
Keyword(s):  
Soil Moisture ◽  
Winter Wheat ◽  
Vegetation Index ◽  
Vegetation Coverage ◽  
Growth Stages ◽  
Wheat Growth ◽  
Inversion Result ◽  
Growing Period ◽  
The Difference ◽  
Different Growth Stages

In the middle and late growing period of winter wheat, soil moisture is easily affected by saturation when using MODIS data to retrieve soil moisture. In this paper, in order to reduce the effect of the saturation caused by increasing vegetation coverage in middle and late stage of winter wheat, the Difference Vegetation Index (DVI) model was modified with different coefficients in different growth stages of winter wheat based on MODIS spectral data and LAI characteristics of variation. LAI was divided into three stages, LAI ≤ 1 < LAI ≤, 3 < LAI, and the adjusting coefficient of α=1, α=3, α=5, were taken to modifying the Difference Vegetation Index(DVI). The results show that the Modified Difference Vegetation Index (MDVIα) can effectively reduce the interference of saturation, and the inversion result of soil moisture in the middle and late period of winter wheat growth is obviously superior to the uncorrected inversion model of DVI.

scholarly journals Effect of Osmotic and Matric Potentials on the Availability of Water for Seed Germination

1971 ◽  
Vol 24 (3) ◽  
pp. 423 ◽  
Author(s):  
JR Mcwilliam ◽  
PJ Phlllips
Keyword(s):  
Soil Moisture ◽  
Seed Germination ◽  
Osmotic Stress ◽  
Soil Water ◽  
Seed Coat ◽  
Moisture Diffusivity ◽  
Matric Potential ◽  
Water Potentials ◽  
Germination Behaviour ◽  
Dry Soil

Under special conditions where soil-moisture diffusivity and seed-soil contact are non-limiting, the osmotic and matric potentials of the substrate were found to be equivalent in their effect on the germination of seeds of ryegrass and dehulled phalaris over a range of water potentials from 0 to -15 bars. However, with intact phalaris seeds it appears that the seed coat constitutes a large resistance to the absorption of soil water, and under these conditions the equivalence between osmotic and matric potential no longer holds, and results of germination under osmotic stress must be used with caution in predicting the germination behaviour of seeds in dry soil.

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