scholarly journals Design and Construction of a Soil Moisture Measuring

Author(s):  
A. A. Ijah ◽  
O. W. Bolaji ◽  
O. O. Adedire ◽  
J. Z. Emmanuel ◽  
N. E. Onwuegbunam ◽  
...  

A digital soil moisture reader was constructed and tested. It uses a lipo battery of 9v which was regulated to a constant 5v with the help of a voltage regulator 7805. The digital soil moisture reader developed was tested and the result obtained was compared with that obtained using the gravimetric method of determining soil moisture contents. In determining the soil moisture content, a certain quantity of soil was collected and a particular volume of water was added incrementally. The result shows that the soil moisture reader is accurate. The evaluation was carried out using the gravimetric method of soil moisture determination as a basis of comparison. Nine samples of 50g of soli were collected from Federal College of Forestry Mechanization Farm and a certain amount of water was added incrementally during the process of determining the soil moisture content. The soil reader was calibrated using the gravimetric method which shows a regression coefficient R^2 of 0.986 which indicates that the soil reader is accurate, sensitive and reliable.

2013 ◽  
Vol 807-809 ◽  
pp. 1648-1652
Author(s):  
Tie Jun Sun ◽  
Baderihu Tajilake

Experiment was executed to plant eco-grass of Bromus inermis Leyss on 15°bare slopes, and study effect of biological characters on dynamics of soil moisture contents. The results indicated that vegetation restored quickly on the bare slope after the eco-grass planted. There were 2473.4 kg/hm2 of overground biomass and 1744.1kg/hm2 of underground biomass, and 70% of underground biomass was in 0-10cm layer of soil. Meanwhile, there was a regulatory mechanism of soil moisture content for Bromus inermis Leyss. When rainfall was enough, soil moisture content in 0-80 cm layer could reach to the most of 26.83% quickly this year. Next it could decline near to the first value of 19.81% after rainfall stopped, and keep a dynamic balance between 19.48% and 19.96%. Moreover, the regulatory mechanism realized though underground biomass, and was clearer with underground biomass increasing, especially in the 0-40cm layer of soil.


Author(s):  
Y. A. Unguwanrimi ◽  
A. M. Sada ◽  
G. N. Ugama ◽  
H. S. Garuba ◽  
A. Ugoani

Draft requirements of two animal – drawn (IAR) weeders operating on loam soil were determined in the study. The implements include a straddle row weeder and an emcot attached rotary weeder evaluated under the same soil conditions, using a pair of white Fulani breed of oxen. The animal draft requirement was first estimated from the animal ergonomics measurements. Using area of 0.054 hectare as experimental plot for each implement the draft requirement of each implement was investigated after taking soil samples for soil moisture content and bulk density determinations. The implements tested showed variation in their average draft requirement. The straddle row weeder had the highest value of 338.15 N respectively while the emcot attached rotary weeder had the lowest value of 188.12 N with 47.03%, respectively. The average soil moisture contents and bulk density were 13.0% and 1.46%/cm3, respectively.


2006 ◽  
Vol 63 (4) ◽  
pp. 341-350 ◽  
Author(s):  
Célia Regina Grego ◽  
Sidney Rosa Vieira ◽  
Aline Maria Antonio ◽  
Simone Cristina Della Rosa

Experiments in agriculture usually consider the topsoil properties to be uniform in space and, for this reason, often make inadequate use of the results. The objective of this study was to assess the variability for soil moisture content using geostatistical techniques. The experiment was carried out on a Rhodic Ferralsol (typic Haplorthox) in Campinas, SP, Brazil, in an area of 3.42 ha cultivated under the no tillage system, and the sampling was made in a grid of 102 points spaced 10 m x 20 m. Access tubes were inserted down to one meter at each evaluation point in order to measure soil moisture contents (cm³ cm-3) at depths of 30, 60 and 90 cm with a neutron moisture gauge. Samplings were made between the months of August and September of 2003 and in January 2004. The soil moisture content for each sampling date was analyzed using classical statistics in order to appropriately describe the central tendency and dispersion on the data and then using geostatistics to describe the spatial variability. The comparison between the spatial variability for different samplings was made examining scaled semivariograms. Water content was mapped using interpolated values with punctual kriging. The semivariograms showed that, at the 60 cm depth, soil water content had moderate spatial dependence with ranges between 90 and 110 m. However, no spatial dependence was found for 30 and 90 cm depths in 2003. Sampling density was insufficient for an adequate characterization of the spatial variability of soil moisture contents at the 30 and 90 cm depths.


2021 ◽  
Vol 12 ◽  
Author(s):  
Haowen Luo ◽  
Meiyang Duan ◽  
Leilei Kong ◽  
Longxin He ◽  
Yulin Chen ◽  
...  

2-acetyl-1-pyrroline (2-AP) is the key compound of rice aroma. However, the responses of 2-AP biosynthesis in fragrant rice under different soil moisture and the corresponding mechanism are little known. The present study evaluated the effects of different soil moisture on 2-AP biosynthesis through a pot experiment. Four soil moisture contents, that is, 50% (SM50), 40% (SM40), 30% (SM30), and 20% (SM20), were adopted, and SM50 treatment was taken as control. The pots were weighed and watered to maintain the corresponding soil moisture content. The results showed no significant difference in growth parameters (plant height, stem diameter, and plant dry weight) among all treatments. Compared with SM50, SM40, SM30, and SM20 treatments significantly (p<0.05) increased 2-AP content by 32.81, 23.18, and 53.12%, respectively. Between 20 to 90% higher proline content was observed in SM40, SM30, and SM20 treatments than in SM50. Enzymes including proline dehydrogenase, ornithine transaminase, and 1-pyrroline-5-carboxylate synthetase exhibited lower activities with soil moisture declined. Higher diamine oxidase activity was observed in SM40, SM30, and SM20 treatments compared with SM50, and real-time PCR analyses showed that transcript level of DAO1 was greatly increased under low soil moisture treatments, especially in SM20 treatment. Transcript levels of PRODH, DAO2, DAO4, DAO5, OAT, P5CS1, and P5CS2 decreased or maintained in SM40, SM30, and SM20 treatments compared with SM50. We deduced that low soil moisture content enhanced 2-AP biosynthesis mainly by upregulating the expression of DAO1 to promote the conversion from putrescine to 2-AP.


2020 ◽  
Vol 39 (3) ◽  
pp. 911-917
Author(s):  
V. Ogwo ◽  
K.N. Ogbu ◽  
C.C. Anyadike ◽  
O.A. Nwoke ◽  
C.C. Mbajiorgu

The quantity and quality of water present in the soil determine to a greater extent the performance of agricultural crops. Real-time determination of moisture content has a greater advantage over the traditional gravimetric method of determining soil moisture content. Thus, this work was based on the design and construction of a cost effective digital capacitive soil moisture sensor for real-time measurement. The moisture sensors comprised four integrated units namely: power supply unit with a 9V DC battery as a power source, sensor unit with a locally sourced Printed Circuit Board (PCB) as the single sensing probe, control unit made up of PIC16f877 microcontroller programmed with a C language and the C source code compiled in Corporate Computer Services Compiler (CSS C) compiler development environment, and a 16x2 display unit which displays the readings in percentage moisture content (%MC) and capacitance (μF) of the soil obtained from the sensor on its screen. Standard gravimetric moisture content was carried out to get the calibration factor which was used to calibrate the sensor for reliability. The validation was done by taking the reprogrammed (calibrated) sensor to the field for further measurement, after which soil samples were collected for further gravimetric analysis. A regression equation was obtained by plotting the moisture content obtained from gravimetric method (%MCG) against that from sensor reading (%MCS) with a high degree correlation coefficient (R2) of 0.998. The developed capacitive soil moisture sensor is cheap, portable, reliable and easy to use even by local farmers. Keywords: Calibration, Capacitive sensor, Printed circuit board, Soil moisture content, Validation.


1966 ◽  
Vol 44 (12) ◽  
pp. 1651-1659 ◽  
Author(s):  
Richard P. Pharis ◽  
William K. Ferrell

By two drought-hardiness tests, "time to death" and "soil-moisture content at the death point", Douglas-fir seedlings from three coastal sources were shown to be less drought resistant than those from five inland sources. Lethal needle-moisture contents, although not a proved test of drought hardiness, tend to confirm this conclusion. In addition, these lethal needle-moisture values, useful as an index of whole plant viability, were established for the various sources. Two of the coastal sources differed from five inland sources in the level of this value, but the lethal points for two other sources from the Oregon Cascade Range were similar to the five inland sources. Needle moisture appears to be a workable index for determining the whole plant viability except when the plant is very close to its time of death. Plants could also be classified into coastal and inland groups on the basis of their needle moisture under well-watered conditions, with the exception of seedlings from the Arizona source which are like the coastal group.


2011 ◽  
Vol 356-360 ◽  
pp. 2440-2444
Author(s):  
Chun Ying Long

The research object is slop near Yingrui highway, we mainly used oven drying method, combined with TDR, carrying out different vegetation types in interchange area and different substrates types in slope area about dynamic monitoring soil moisture in the spring. According to the result, The daily dynamic of the 2 types of slop soil moisture content has no obvious regular pattern, but each time the moisture content in soil slope are higher than rocky slope. We can get the conclusion after variance analysis, the main factors which influencing the discretion of the soil moisture content in slope and interchange area are the slope matrix type and the different vegetation reconstruction mode in interchange area. Meanwhile, according to the data, which we applied to the same experiment with both TDR and oven drying method, and after comparative analysis, we think, it’s completely effective to make TDR applied in deep soil moisture determination in some places such as interchange area, but the data about shallow soil moisture determination which got from the places such as in side slope is inaccurate. We should be more cautious when using it.


2015 ◽  
Vol 62 (1) ◽  
pp. 14-25
Author(s):  
Michal Allman ◽  
Martin Jankovský ◽  
Zuzana Allmanová ◽  
Valéria Messingerová

Abstract This paper was focused on determining whether gravimetric sampling and impedance method of measuring soil moisture content provided different results and if they did, what was the size of the differences between particular methods on rendzinas and cambisols. The means of moisture content should be equal when using both methods on similar spots. During the research, an Eijkelkamp Penetrologger penetrometer equipped with impedance probes and gravimetric sampling cylinders from Eijkelkamp were used. The samples were taken from the undisturbed stand, ruts, and the centre of the skid trail. The impedance probes were inserted six centimetres deep into the soil. Soil samples were taken from similar depth in order to calculate the moisture content through the gravimetric method. 138 measurements were carried out for each method. The minimal difference of moisture contents measured by individual methods was 0.01%, maximal difference was 22.06%, and on average it was 7.42%. Oneway ANOVA was used for first stage analysis of the statistical sample. It proved that the differences between measurements were statistically significant in two out of three considered stands. Tukey’s HSD test was used to identify which data groups contributed to refuting the aforementioned hypothesis. The test showed that in one stand all relevant pairs of data were significantly different, while in the other stand only data pairs from the ruts were significantly different. The calibration method provided by the producers did not refine the accuracy of the impedance probes sufficiently and different calibration procedures have to be used.


1960 ◽  
Vol 40 (2) ◽  
pp. 264-269 ◽  
Author(s):  
J. J. Lehane ◽  
W. J. Staple

Permanent wilting percentages based on the wilting of the upper leaves of sunflower plants were related to the 15-atmosphere percentage by the equation PWP = 0.35 + 0.833 FAP. This wilting percentage, which was lower than that based on a mean wilting condition of the plant as a whole, provided satisfactory estimates of minimum soil moisture contents under cereal crops at harvest time.


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