Retrieving parameters of bare soil surface roughness and soil water content under arid environment from ERS-1, -2 SAR data

2013 ◽  
Vol 34 (17) ◽  
pp. 6202-6215 ◽  
Author(s):  
Arthur Genis ◽  
Leonid Vulfson ◽  
Dan G. Blumberg ◽  
Michael Sprinstin ◽  
Alexey Kotlyar ◽  
...  
Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 651 ◽  
Author(s):  
Amir Orangi ◽  
Guillermo A. Narsilio ◽  
Dongryeol Ryu

Soil water content is an important parameter in many engineering, agricultural and environmental applications. In practice, there exists a need to measure this parameter rather frequently in both time and space. However, common measurement techniques are typically invasive, time-consuming and labour-intensive, or rely on potentially risky (although highly regulated) nuclear-based methods, making frequent measurements of soil water content impractical. Here we investigate in the laboratory the effectiveness of four new low-cost non-invasive sensors to estimate the soil water content of a range of soil types. While the results of each of the four sensors are promising, one of the sensors, herein called the “AOGAN” sensor, exhibits superior performance, as it was designed based on combining the best geometrical and electronic features of the other three sensors. The performance of the sensors is, however, influenced by the quality of the sensor-soil coupling and the soil surface roughness. Accuracy was found to be within 5% of volumetric water content, considered sufficient to enable higher spatiotemporal resolution contrast for mapping of soil water content.


2010 ◽  
Vol 34 (5) ◽  
pp. 1733-1741 ◽  
Author(s):  
Thais Emanuelle Monteiro dos Santos ◽  
Demetrius David da Silva ◽  
Abelardo Antônio de Assunção Montenegro

Rainfall in the semiarid region of Pernambuco is characterized by irregular distribution in time and space, which significantly hinders the rainfed agriculture in the region. This work aims to evaluate the temporal profile of soil moisture in the semiarid region of the Pernambuco State (Brazil) and the effect of different soil surface conditions on soil water content variation and the yield of rainfed beans. To monitor soil water content, five plots 4.5 m wide by 11 m long were installed in a Yellow Argisol (Ultisol). The following treatments were adopted in the experimental plots: natural vegetation, bean intercropped with cactus, beans planted down the slope, beans planted along contour lines with mulch and rock barriers, and bare soil. In each plot, eight PVC access tubes were installed for monitoring the soil water content profile at depths of 0.20 and 0.40 m using a neutron probe device. The surface condition significantly influenced the soil water content variation, both in the dry and rainy seasons. The use of mulch, associated with rock barriers, provided higher soil water content levels than the other treatments and increased the rainfed beans production.


1994 ◽  
Vol 74 (3) ◽  
pp. 485-495 ◽  
Author(s):  
C. Wagner-Riddle ◽  
T. J. Gillespie ◽  
C. J. Swanton

The optimum killing time of a rye (Secale cereale) cover crop is an important management decision and can determine the yield of the subsequent soybean (Glyane max) crop The objective of this research was to study a rye cover/soybean system. Soybeans were grown on sandy (Delhi) and loam (Woodstock) soils (1989/1990) with mulch on the soil surface obtained by killing rye approximately 1 and 2 wk before soybean planting. A conventional tillage treatment was used as a control. Soil water content, soil temperature, rye mulch amount and soybean growth were monitored over the season. Rye mulch amount for the late killing (LK) date was always larger than for the ear y killing (EK) date. LK decreased soil water content at soybean planting time at Delhi in 1989. The rye mulch produced with the LK increased soil water content early in the soybean growing season in 1990. A substantial decrease in the amount of mulch was observed during the growing season and resulted in little difference between mulch and no mulch soil water and temperature conditions later in the season. Extreme temperatures were more frequent under the bare soil, but these were limited to a small percentage of hours, and did not translate into differences in soybean development rates. Reduced soybean growth observed early in the season in one out of four location-years vanished as the season progressed. Number of seeds per pod and nodule number were increased due to rye mulch, but no difference in soybean yields were observed among treatments. Key words: Rye (Secale cereale), cover crop, mulch, soybean (Glycine max)


1983 ◽  
Vol 23 (123) ◽  
pp. 407 ◽  
Author(s):  
PS Cornish

A temporary watertable was established in large undisturbed cores of a podzolic (duplex) soil in a glasshouse. The upward flow of water from the watertable to the soil surface through a 7 d drying cycle was assessed by measuring soil water content and matric potential, and the rate of evaporation from the soil surface (by weighing). Evaporation from the soil surface (Ea) closely followed evaporation from a free water surface (Eo), with little change in surface water potential or content until the watertable was depleted. This indicated that soil evaporation was balanced by the upward flux from the watertable, at rates up to 0.37 mm/h. Surface water potential was maintained above - 0.04 MPa for 7 d, and 12% of ryegrass seeds established themselves on the bare soil surface. When the A horizon was wet to field capacity but no watertable was established, Ea was much less than Eo especially in periods of high evaporation. Also, the soil surface dried to below - 0.04 MPa within the first day and no seeds germinated. It appears that sowing on sites with temporary watertables could assist germination and establishment after aerial sowing.


2010 ◽  
Vol 53 (10) ◽  
pp. 1527-1532 ◽  
Author(s):  
YuanJun Zhu ◽  
YunQiang Wang ◽  
MingAn Shao

2005 ◽  
Vol 60 (5) ◽  
pp. 1013-1016
Author(s):  
Reiji KIMURA ◽  
Yuanbo LIU ◽  
Naru TAKAYAMA ◽  
Makio KAMICHIKA ◽  
Nobuhiro MATSUOKA ◽  
...  

2006 ◽  
Vol 63 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Luís Carlos Timm ◽  
Luiz Fernando Pires ◽  
Renato Roveratti ◽  
Robson Clayton Jacques Arthur ◽  
Klaus Reichardt ◽  
...  

Soil water content (theta) and bulk density (rhos) greatly influence important soil and plant processes, such as water movement, soil compaction, soil aeration, and plant root system development. Spatial and temporal variability of theta and rhos during different periods of the year and different phases of crops are of fundamental interest. This work involves the characterization of spatial and temporal patterns of theta and rhos during different climatic periods of year, aiming to verify whether there are significant temporal changes in rhos at the soil surface layer when submitted to wetting and drying cycles. The field experiment was carried out in a coffee plantation, Rhodic Kandiudalf soil, clayey texture. Using a neutron/gamma surface probe, theta and rhos were measured meter by meter along a 200 m spatial transect, along an interrow contour line. During the wet period there was no difference of spatial patterns of theta while during the dry period differences were observed, and can be associated to precipitation events. It was also observed that there are rhos temporal changes at the soil surface along the studied period as a consequence of the in situ wetting and drying cycles.


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