scholarly journals MEASUREMENT OF WOOD MOISTURE CONTENT USING THE COLMAN ELECTRODE

1965 ◽  
Vol 41 (3) ◽  
pp. 352-363
Author(s):  
W. J. Bloomberg ◽  
D. Farrell

Colman electrodes were inserted into stem sections of Douglas-fir, western hemlock, western red cedar and black cottonwood and resistance readings were taken at wood moisture contents of 10% to 100% of maximum moisture content. In almost all the conifer sections tested, 85% or more of the readings lay within limits of ±10% moisture content about the mean curve, and over 50% were within ±5%. The variation was greater for black cottonwood. Variation was also greater in the larger than in the smaller sections. The curves for individual sections within each species had certain characteristics in common, but no two curves were identical.Resistance readings given by Colman electrodes inserted into living black cottonwood trees showed a fairly good correlation with soil moisture content when the trees were subjected to cycles of drought and watering.

1969 ◽  
Vol 45 (2) ◽  
pp. 107-113
Author(s):  
Gy. Péch

Seven composite samples of western red cedar and western hemlock logging slash of 0.25 to 2 inches diameter were exposed on top of and within the bottom third of a fuel bed in the interior wet belt of British Columbia in August 1965. Their moisture contents were measured regularly 24 hours a day and compared with the moisture content of an exposed B.C. hazard stick on the basis of both the hourly drying rates on 1 clear day and the daily loss of moisture, relative to the morning maximum moisture content, for a period of 6 drying days after rain. The absolute moisture content values, the hourly rates of drying, and the daily fluctuation of the moisture content of the hazard stick differed from those of the fuel samples at all times. It was concluded that cedar-hemlock slash fuel moisture content cannot be predicted numerically from an individual measurement of the moisture content of freely exposed hazard sticks in those years when the slash retains a tight bark. Counting the number of drying days after rain proved to be of little practical value.


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.


1959 ◽  
Vol 37 (5) ◽  
pp. 789-799 ◽  
Author(s):  
D. A. Fraser ◽  
H. T. Dirks

Wood moisture was measured in the butt of healthy and decadent yellow birch trees growing on various sites in the summers of 1950 and 1952. The moisture content decreased from almost 100% in May to about 60% in late June when the leaves were fully unfolded. Wood moisture was usually 5 to 15% higher in the butt of decadent trees than in healthy trees during the 2 years of investigations. It was higher in the trunk of trees on a dry site during a wet summer and on a wet site during a somewhat dry summer.Relative turgidity in leaves was measured in mature trees as well as in leaves of seedlings growing on soils with varied moisture contents. Relative turgidity was usually less during the day. During periods of drought it decreased even during the night. Exceptions observed may have been caused by leaf absorption of dew. In young birch seedlings relative turgidity values varied between 65 and 50% in soils ranging from 100 to 70% of field capacity. As the soil wilting point was approached, relative turgidity of leaves decreased to about 35%.


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.


2014 ◽  
Vol 931-932 ◽  
pp. 1574-1581
Author(s):  
Nirattisak Khongthon ◽  
Somposh Sudajan

The physical and mechanical properties of sugarcane leaves were necessary for the design consideration of the relating storage, handling and processing equipment. The sugarcane trash at moisture contents of 23.40 and 73.91 % w.b. were used for this study. The mean length and unit weight of sugarcane trashes were 168.63 cm and 65.87 grams respectively. The average number of leaf of each sample was 4. The mean diameter of the thrash top, width and thickness increased with the increase of moisture from 23.40 and 73.91 % w.b.. The average leaf angles (β) relative to the horizontal plane of the first left leaf, second left leaf, first right leaf and second right leaf were 65.10, 73.36, 71.07 and 78.26 degrees for 73.91 % w.b., and 66.33, 73.50, 67.50 and 75.83 degrees for 23.40 % w.b. respectively. When the moisture content increased from 23.40 to 73.91% w.b., the static coefficient of friction increased from 0.30 to 0.43, 0.38 to 0.41, 0.30 to 0.37 and 0.54 to 0.66 for plywood, mild steel, galvanized iron and rubber plate respectively. The least static coefficient of friction occurred on the galvanized iron plate. The results from experimenting on mechanical properties showed that the maximum shearing force increased with the increase in moisture content from 23.40 to 73.91% w.b. respectively. The maximum shearing force was 360.15 and 457.32 N for moisture contents of 23.40 and 73.91% w.b.. The maximum tensile force decreased toward upper region of the leaf for both 23.40 and 73.91% w.b.. The results of this study would be useful for the design and optimization of the equipment associated with harvesting, threshing, chopping and processing.


1991 ◽  
Vol 21 (9) ◽  
pp. 1415-1418 ◽  
Author(s):  
Gyula Péch

Four reindeer lichen (Cladinarangiferina (L.) Nyl) samples were placed near ground level in the open at a meteorological station where dew and other meteorological parameters were measured. One sample was covered occasionally from sunset to sunrise to prevent dew and to evaluate moisture gain due to wetting by atmospheric vapour alone. Mass measurements were done day and night following a set schedule. At the conclusion of the field program the samples were oven-dried and all weight measurements were converted to moisture contents. The results showed that a simple linear relationship adequately describes the overnight rise of lichen moisture caused by dew, and that atmospheric vapour alone, on nights without rain or condensation, can raise lichen moisture by 15%. Further, the results confirmed that nocturnal moisture gains by either dew or atmospheric vapour dissipate on subsequent clear mornings by noon. These findings suggest that at locations where humidity is measured at night and dew may be assessed visually in the morning, one can estimate both the 06:00 maximum moisture content of the lichen and, on subsequent clear mornings, the hourly rate of its drying.


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.


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.


1962 ◽  
Vol 40 (10) ◽  
pp. 1281-1292 ◽  
Author(s):  
W. J. Bloomberg

A comparison was made between Populus trichocarpa Torr. and Gray, P. × canadensis Moench 'Regenerata', and P. × canadensis 'Robusta Bachelieri' with respect to shoot moisture relations and anatomy. The two hybrid varieties had slower rates of moisture loss and had higher wood moisture contents throughout most of the year than P. trichocarpa. The bark and wood moisture content of the three varieties was lower during dormancy than in the growing season. The upper region of the shoots had lower bark and wood moisture contents than the basal region during dormancy, but the reverse was true in summer. In all varieties, there was a significant positive correlation between wood and bark moisture content. Compared with P. trichocarpa, the two hybrids had larger piths, wider vessels, longer phloem rays, wider sieve tube zones, and thicker periderms; P. 'Robusta' had fewer lenticels. The upper region of the shoots had a wider pith, thicker bark, thinner periderm, and more lenticels than the basal region. The differences in moisture relations and anatomy of the three varieties suggest an explanation for the observed greater resistance to canker disease caused by Cytospora chrysosperma (Pers.) Fr. in the hybrids than in P. trichocarpa.


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