Effect of temperature and soil moisture content on the colonization of the wheat rhizosphere by antiphytopathogenic bacilli

Microbiology ◽  
2000 ◽  
Vol 69 (3) ◽  
pp. 351-356 ◽  
Author(s):  
A. I. Melent’ev ◽  
L. Yu. Kuz’mina ◽  
N. F. Galimzyanova
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Effect Of Temperature ◽  
Wheat Rhizosphere

scholarly journals Role of Climatic Factors In The Toxicity of Fipronil Toward Earthworms In Two Tropical Soils: Effects of Increased Temperature And Reduced Soil Moisture Content

2021 ◽  
Author(s):  
Thuanne Braúlio Hennig ◽  
Paulo Roger Lopes Alves ◽  
Felipe Ogliari Bandeira ◽  
Liziara da Costa Cabrera ◽  
Jonas Simon Dugatto ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Climatic Factors ◽  
Hazard Quotient ◽  
Tropical Soils ◽  
Effect Of Temperature ◽  
Water Holding ◽  
Water Contents

Abstract The aim of this study was to assess the effect of temperature on the toxicity of fipronil toward earthworms (Eisenia andrei) in two Brazilian soils (Entisol and Oxisol) with contrasting textures. In the case of Entisol, the influence of the soil moisture content on the toxicity was also investigated. Earthworms were exposed for 56 days to soils spiked with increasing concentrations of fipronil under scenarios with different combinations of temperature (20, 25 and 27 ºC) and soil moisture content (60 and 30% of water holding capacity (WHC) for Entisol and 60% WHC for Oxisol). The number of juveniles produced was taken as the endpoint and a risk assessment was performed based on the hazard quotient (HQ). In Entisol, at 60% WHC the fipronil toxicity decreased at 27 ºC compared with the other temperatures tested (EC50 = 52.58, 48.48 and 110 mg kg-1 for 20, 25 and 27 ºC, respectively). In the case of Oxisol at 60% WHC, the fipronil toxicity increased at 27 ºC compared with other temperatures (EC50 = 277.57, 312.87 and 39.89 mg kg-1 at 20, 25 and 27 ºC, respectively). An increase in fipronil toxicity was also observed with a decrease in soil moisture content in Entisol at 27 ºC (EC50 = 27.95 and 110 mg kg-1 for 30% and 60% WHC, respectively). The risk of fipronil was only significant at 27 ºC in Entisol and Oxisol with water contents of 30% and 60% WHC, respectively, revealing that higher temperatures can increase the risk of fipronil toxicity toward earthworms. The results reported herein show that soil properties associated with climatic shifts could enhance the ecotoxicological effects and risk of fipronil for earthworms, depending on the type of soil.

Effect of Environmental Factors on Pyrazon Action in Sugar Beets

Weed Science ◽  
1971 ◽  
Vol 19 (5) ◽  
pp. 587-592 ◽  
Author(s):  
Ephraim Koren ◽  
Floyd M. Ashton
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Sugar Beet ◽  
Soil Moisture Content ◽  
Chenopodium Album ◽  
Effect Of Temperature ◽  
Sugar Beets ◽  
Common Lambsquarters ◽  
Lag Period ◽  
Great Accumulation

The effect of temperature and soil moisture content on the toxicity of soil-applied 5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone (pyrazon) to sugar beets (Beta vulgaris L. ‘U.S. H-8’) was studied under controlled environmental conditions. High temperatures during or after germination increased the susceptibility of sugar beets to pyrazon while variations in soil moisture content did not have a significant effect. Sugar beet seeds absorbed three times more pyrazon at 35 C than at 18.3 C. During imbibition more than 90% of the pyrazon taken up by sugar beet fruits was concentrated in the pericarps surrounding the seeds. Furthermore, the herbicide which had been accumulated in the pericarp during imbibition did not move into the tissues of the developing seedling during or after germination. Comparative studies showed that there was a lag period in absorption of pyrazon by sugar beet seeds enclosed within their pericarps. This lag period did not occur in sugar beet seeds from which the pericarps had been removed, or in seeds of common lambsquarters (Chenopodium album L.). It is concluded, therefore, that the pericarp contributes to a physical mechanism of selectivity which enables sugar beets to avoid great accumulation of pyrazon when the mechanism of biochemical inactivation of the herbicide is not yet operative.

Analysis on Soil Moisture Content in the Middle Reaches of the Yellow River

2011 ◽  
Vol 28 (1) ◽  
pp. 85-91 ◽  
Author(s):  
Run-chun LI ◽  
Xiu-zhi ZHANG ◽  
Li-hua WANG ◽  
Xin-yan LV ◽  
Yuan GAO
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Yellow River ◽  
The Yellow River

Distribution of soil moisture content and its effect on the potential growth of the over-story species in North-East Chalkidiki

2001 ◽  
Vol 66 ◽  
Author(s):  
M. Aslanidou ◽  
P. Smiris
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Soil Depth ◽  
Moisture Distribution ◽  
Taxus Baccata ◽  
Mixed Stands ◽  
Potential Growth ◽  
North East ◽  
Soil Moisture Distribution

This  study deals with the soil moisture distribution and its effect on the  potential growth and    adaptation of the over-story species in north-east Chalkidiki. These  species are: Quercus    dalechampii Ten, Quercus  conferta Kit, Quercus  pubescens Willd, Castanea  sativa Mill, Fagus    moesiaca Maly-Domin and also Taxus baccata L. in mixed stands  with Fagus moesiaca.    Samples of soil, 1-2 kg per 20cm depth, were taken and the moisture content  of each sample    was measured in order to determine soil moisture distribution and its  contribution to the growth    of the forest species. The most important results are: i) available water  is influenced by the soil    depth. During the summer, at a soil depth of 10 cm a significant  restriction was observed. ii) the    large duration of the dry period in the deep soil layers has less adverse  effect on stands growth than in the case of the soil surface layers, due to the fact that the root system mainly spreads out    at a soil depth of 40 cm iii) in the beginning of the growing season, the  soil moisture content is    greater than 30 % at a soil depth of 60 cm, in beech and mixed beech-yew  stands, is 10-15 % in    the Q. pubescens  stands and it's more than 30 % at a soil depth of 60 cm in Q. dalechampii    stands.

scholarly journals Mapping barrier island soil moisture using a radiative transfer model of hyperspectral imagery from an unmanned aerial system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rehman S. Eon ◽  
Charles M. Bachmann
Keyword(s):  
Soil Moisture ◽  
Radiative Transfer ◽  
Moisture Content ◽  
Layer Thickness ◽  
Soil Moisture Content ◽  
Hyperspectral Imagery ◽  
Barrier Island ◽  
Water Layer ◽  
Radiative Transfer Model ◽  
Transfer Model

AbstractThe advent of remote sensing from unmanned aerial systems (UAS) has opened the door to more affordable and effective methods of imaging and mapping of surface geophysical properties with many important applications in areas such as coastal zone management, ecology, agriculture, and defense. We describe a study to validate and improve soil moisture content retrieval and mapping from hyperspectral imagery collected by a UAS system. Our approach uses a recently developed model known as the multilayer radiative transfer model of soil reflectance (MARMIT). MARMIT partitions contributions due to water and the sediment surface into equivalent but separate layers and describes these layers using an equivalent slab model formalism. The model water layer thickness along with the fraction of wet surface become parameters that must be optimized in a calibration step, with extinction due to water absorption being applied in the model based on equivalent water layer thickness, while transmission and reflection coefficients follow the Fresnel formalism. In this work, we evaluate the model in both field settings, using UAS hyperspectral imagery, and laboratory settings, using hyperspectral spectra obtained with a goniometer. Sediment samples obtained from four different field sites representing disparate environmental settings comprised the laboratory analysis while field validation used hyperspectral UAS imagery and coordinated ground truth obtained on a barrier island shore during field campaigns in 2018 and 2019. Analysis of the most significant wavelengths for retrieval indicate a number of different wavelengths in the short-wave infra-red (SWIR) that provide accurate fits to measured soil moisture content in the laboratory with normalized root mean square error (NRMSE)< 0.145, while independent evaluation from sequestered test data from the hyperspectral UAS imagery obtained during the field campaign obtained an average NRMSE = 0.169 and median NRMSE = 0.152 in a bootstrap analysis.

scholarly journals Estimating Agricultural Soil Moisture Content through UAV-Based Hyperspectral Images in the Arid Region

2021 ◽  
Vol 13 (8) ◽  
pp. 1562
Author(s):  
Xiangyu Ge ◽  
Jianli Ding ◽  
Xiuliang Jin ◽  
Jingzhe Wang ◽  
Xiangyue Chen ◽  
...  
Keyword(s):  
Data Mining ◽  
Soil Moisture ◽  
Moisture Content ◽  
Hyperspectral Imaging ◽  
Fractional Order ◽  
Arid Regions ◽  
Soil Moisture Content ◽  
Order Derivative ◽  
Imaging Data ◽  
Strategy I

Unmanned aerial vehicle (UAV)-based hyperspectral remote sensing is an important monitoring technology for the soil moisture content (SMC) of agroecological systems in arid regions. This technology develops precision farming and agricultural informatization. However, hyperspectral data are generally used in data mining. In this study, UAV-based hyperspectral imaging data with a resolution o 4 cm and totaling 70 soil samples (0–10 cm) were collected from farmland (2.5 × 104 m2) near Fukang City, Xinjiang Uygur Autonomous Region, China. Four estimation strategies were tested: the original image (strategy I), first- and second-order derivative methods (strategy II), the fractional-order derivative (FOD) technique (strategy III), and the optimal fractional order combined with the optimal multiband indices (strategy IV). These strategies were based on the eXtreme Gradient Boost (XGBoost) algorithm, with the aim of building the best estimation model for agricultural SMC in arid regions. The results demonstrated that FOD technology could effectively mine information (with an absolute maximum correlation coefficient of 0.768). By comparison, strategy IV yielded the best estimates out of the methods tested (R2val = 0.921, RMSEP = 1.943, and RPD = 2.736) for the SMC. The model derived from the order of 0.4 within strategy IV worked relatively well among the different derivative methods (strategy I, II, and III). In conclusion, the combination of FOD technology and the optimal multiband indices generated a highly accurate model within the XGBoost algorithm for SMC estimation. This research provided a promising data mining approach for UAV-based hyperspectral imaging data.

Sign in / Sign up

Export Citation Format

Share Document