RELATIONSHIP OF THE PERMANENT WILTING PERCENTAGE AND THE SOIL MOISTURE CONTENT AT HARVEST TO THE 15-ATMOSPHERE PERCENTAGE

1960 ◽  
Vol 40 (2) ◽  
pp. 264-269 ◽  
Author(s):  
J. J. Lehane ◽  
W. J. Staple
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Cereal Crops ◽  
Harvest Time ◽  
Moisture Contents ◽  
Relationship Of

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.

Effect of Bromus inermis Leyss Planting on Dynamic Changes of Soil Moisture Contents on the Bare Slope

2013 ◽  
Vol 807-809 ◽  
pp. 1648-1652
Author(s):  
Tie Jun Sun ◽  
Baderihu Tajilake
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Regulatory Mechanism ◽  
Dynamic Balance ◽  
Bromus Inermis ◽  
Dynamic Changes ◽  
Moisture Contents ◽  
Biological Characters ◽  
Underground Biomass

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.

scholarly journals Draft Requirement of Two Animal - Drawn Institute for Agricultural Research (IAR) Weeders

2020 ◽  
pp. 14-20
Author(s):  
Y. A. Unguwanrimi ◽  
A. M. Sada ◽  
G. N. Ugama ◽  
H. S. Garuba ◽  
A. Ugoani
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Bulk Density ◽  
Soil Moisture Content ◽  
Agricultural Research ◽  
Soil Samples ◽  
Soil Conditions ◽  
Experimental Plot ◽  
Moisture Contents ◽  
Loam Soil

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.

scholarly journals Geostatistical analysis for soil moisture content under the no tillage cropping system

2006 ◽  
Vol 63 (4) ◽  
pp. 341-350 ◽  
Author(s):  
Célia Regina Grego ◽  
Sidney Rosa Vieira ◽  
Aline Maria Antonio ◽  
Simone Cristina Della Rosa
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Spatial Variability ◽  
Water Content ◽  
Spatial Dependence ◽  
Soil Moisture Content ◽  
No Tillage ◽  
Moisture Contents ◽  
Classical Statistics ◽  
Evaluation Point

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.

scholarly journals Design and Construction of a Soil Moisture Measuring

2020 ◽  
pp. 29-34
Author(s):  
A. A. Ijah ◽  
O. W. Bolaji ◽  
O. O. Adedire ◽  
J. Z. Emmanuel ◽  
N. E. Onwuegbunam ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Regression Coefficient ◽  
Gravimetric Method ◽  
Voltage Regulator ◽  
Moisture Determination ◽  
Moisture Contents ◽  
Design And Construction

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.

scholarly journals The Regulatory Mechanism of 2-Acetyl-1-Pyrroline Biosynthesis in Fragrant Rice (Oryza sativa L.) Under Different Soil Moisture Contents

2021 ◽  
Vol 12 ◽  
Author(s):  
Haowen Luo ◽  
Meiyang Duan ◽  
Leilei Kong ◽  
Longxin He ◽  
Yulin Chen ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Growth Parameters ◽  
Oryza Sativa L ◽  
Dry Weight ◽  
Transcript Level ◽  
Fragrant Rice ◽  
Moisture Contents ◽  
Significant Difference

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.

scholarly journals Drainage criteria for soil workability.

1979 ◽  
Vol 27 (1) ◽  
pp. 27-35
Author(s):  
L.K. Smedema
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Soil Management ◽  
Field Capacity ◽  
Design Criteria ◽  
Plastic Limit ◽  
Drainage Design ◽  
Relationship Of ◽  
The Relationship

Drainage requirements for workability are formulated on the basis of the soil moisture content at the lower plastic limit, and the relationship of the latter value to field capacity is investigated. Current drainage design criteria are analysed with respect to soil workability requirements; it is concluded that there is little technical and even less economic scope for improving soil workability by adopting stricter criteria, leading to narrower drain spacings. However, a case can be made for increasing the drain depth in medium and heavy textured soils beyond the commonly applied depth of about 100 cm, in the Netherlands. The effects of soil management on soil workability are briefly discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)

DIFFERENCES IN DROUGHT RESISTANCE BETWEEN COASTAL AND INLAND SOURCES OF DOUGLAS FIR

1966 ◽  
Vol 44 (12) ◽  
pp. 1651-1659 ◽  
Author(s):  
Richard P. Pharis ◽  
William K. Ferrell
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Douglas Fir ◽  
Cascade Range ◽  
Time Of Death ◽  
Time To Death ◽  
Moisture Contents ◽  
Whole Plant ◽  
Drought Resistant

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.

scholarly journals Field and laboratory ad hoc calibrations of Virrib and ThetaProbe dielectric sensors for soil moisture measurements

2008 ◽  
Vol 3 (No. 4) ◽  
pp. 199-214 ◽  
Author(s):  
F. Doležal ◽  
T. Litschmann ◽  
J. Kučera ◽  
J. Peterková ◽  
J. Zavadil ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Calibration Curve ◽  
Ad Hoc ◽  
Soil Moisture Content ◽  
Seasonal Pattern ◽  
Repeated Measurements ◽  
Field Calibration ◽  
Moisture Contents ◽  
Moisture Variation

For the research of irrigation optimization and nitrate leaching it is important to know the short-term soil moisture variation during percolation episodes as well as its seasonal pattern. Dielectric soil moisture sensors Virrib (AMET – Consortium) and ThetaProbe ML2x (Delta-T) were used for this purpose over several years for measuring soil moisture content at hourly intervals in Valečov (49°38’40” N, 14°30’25” E, 461 m a.s.l.), Czech Republic, in a deep loamy Stagnosol soil underlain by weathered paragneiss. One-point field calibration was made each spring at the time of sensor installation over three (for Virribs) or two (for ThetaProbes) consecutive years by taking sensor readings and soil samples (at least one 100 cm3 core sample near to each sensor) in parallel. A supplementary check was then made in the laboratory by taking readings of individual sensors, inserted into pre-made loamy-sand mixtures with various moisture contents. During both the field calibration and the laboratory check, the readings were taken manually, using either the AMET hand-held meter or the EMS ModuLog datalogger. The results suggest that the average slope of the secondary Virrib calibration curve (defined as the plot of y = sensor readings in terms of moisture content vs. x = soil moisture content determined gravimetrically) is near to unity, but the offsets are quite large and vary from probe to probe. The axial zone of influence of the Virrib sensors is up to about 30 cm, as it follows from both laboratory and field observations. The results of the laboratory check of Virribs were biased, because the volume of the soil was not large enough and the soil had different dry bulk densities at different moisture contents. The field secondary calibration curve of ThetaProbes appears to be roughly linear, in contrast to the laboratory calibration curve, because of absence of very low moisture contents in the field. If the same calibration line is applied to several different depths, then its slope is statistically significantly lower then unity, due to the dependence of ThetaProbe readings on the soil bulk density. The overall accuracy of the sensors and its components due to different factors is estimated from the statistics of repeated measurements.

scholarly journals Some results of field determinations of the moisture content of soil from thermal conductivity measurements.

1953 ◽  
Vol 1 (2) ◽  
pp. 115-121
Author(s):  
D.A. De Vries
Keyword(s):  
Thermal Conductivity ◽  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Potential Evapotranspiration ◽  
Sandy Soils ◽  
Clay Soils ◽  
Conductivity Measurements ◽  
General Increase ◽  
Moisture Contents

The soil-moisture content at 4-I6-cm depth is compared with precipitation and potential evapotranspiration for periods of one month. During May the moisture contents fluctuated under the influence of frequent rainfall. From the end of May evapotranspiration exceeded precipitation and, during the dry months June and July, rainfall affected only the measurements at 4-cmdepth; moisture contents at 8 and I6 cm became constant after initial drying. During August, rainfall exceeded evapotranspiration and there was a general increase in moisture content. Diurnal variation in moisture content is shown in graphs. For accurate determinations of soil-moisture content from thermal conductivity measurements sandy soils are more suitable than clay soils. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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