scholarly journals Effects of Variable Angular Velocities and Soil Moisture Contents on Undrained Shear Strength in a Sandy Loam Soil (Eutric Leptosol)

2016 ◽  
Vol 11 (2) ◽  
pp. 49-60
Author(s):  
David Lomeling ◽  
Juma L.L. Yieb ◽  
Modi A. Lodiong ◽  
Mandlena C. Kenyi ◽  
Moti S. Kenyi ◽  
...  
Keyword(s):  
Shear Strength ◽  
Soil Moisture ◽  
Sandy Loam ◽  
Undrained Shear Strength ◽  
Sandy Loam Soil ◽  
Moisture Contents ◽  
Angular Velocities ◽  
Loam Soil ◽  
Undrained Shear

Soil water drying and recharge rates as affected by tillage under continuous barley and barley-canola cropping systems in northwestern Canada

2001 ◽  
Vol 81 (1) ◽  
pp. 45-52 ◽  
Author(s):  
R H Azooz ◽  
M A Arshad
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Sandy Loam ◽  
Time Domain Reflectometry ◽  
Sandy Loam Soil ◽  
Soil Conditions ◽  
Silt Loam ◽  
Silt Loam Soil ◽  
Loam Soil ◽  
The Impact

In areas of the northwestern Canadian Prairies, barley and canola are grown in a short growing season with high rainfall variability. Excessively dry soil in conventional tillage (CT) in dry periods and excessively wet soil in no-tillage (NT) in wet periods could cause a significant decrease in crop production by influencing the availability of soil water. The effects of CT, NT and NT with a 7.5-cm residue-free strip on the planting rows (NTR) on soil water drying (–dW/dt) and recharge (dW/dt) rates were studied in 1992 and 1993 during wet and dry periods to evaluate the impact of NTR, NT and CT systems on soil moisture condition. The soils, Donnelly silt loam and Donnelly sandy loam (both Gray Luvisol) were selected and soil water content by depth was measured by time domain reflectometry. Water retained at 6 matric potentials from –5 to –160 kPa were observed. In the field study, –dW/dt was significantly greater in CT than in NT in the silt loam for the 0- to 30-cm layer during the first 34 d after planting in 1992. The 0- to 30-cm soil layer in CT and NTR dried faster than in NT during a period immediately following heavy rainfall in the silt loam in 1993. The drying coefficient (–Kd ) was significantly greater in CT and NTR than in NT in the silt loam soil in 1993 and in the sandy loam soil in 1992 in the top 30-cm depth. The recharge coefficient (Kr) was significantly greater in NT and NTR than in CT for the silt loam soil. The NTR system increased the –dW/dt by 1.2 × 10-2 to 12.1 × 10-2 cm d-1 in 1992 and 1993 in the silt loam soil and by 10.2 × 10-2 cm d-1 in 1993 in the sandy loam soil as compared with NT. The dW/dt was 8.1 × 10-2 cm d-1 greater in NTR in 1992 and 1993 in the silt loam soil and was 1.9 × 10-2 greater in NTR in 1992 than in CT in the sandy loam soil. The laboratory study indicated that NT soils retained more water than the CT soils. The NTR practice maintained better soil moisture conditions for crop growth than CT in dry periods than NT in wet periods. Compared with NT, the NTR avoided prolonged near-saturated soil conditions with increased soil drying rate under extremely wet soil. Key words: Water drying, water recharge, water depletion, wet and drying periods, hydraulic properties, soil capacity to retain water

INFLUENCE OF BULK DENSITY AND FIELD STRUCTURE OF SOIL ON THE CALIBRATION CURVES OF GYPSUM MOISTURE BLOCKS

1959 ◽  
Vol 39 (1) ◽  
pp. 12-19
Author(s):  
S. J. Bocrget
Keyword(s):  
Soil Moisture ◽  
Bulk Density ◽  
Sandy Loam ◽  
Field Structure ◽  
Sandy Loam Soil ◽  
Soil Types ◽  
Soil Cores ◽  
Field Density ◽  
Calibration Curves ◽  
Loam Soil

Gypsum moisture blocks were calibrated in the laboratory in undisrupted soil cores, in soil cores which had been repacked to field density, and in unpacked soil baskets. Three soil types were used. It was found that the calibration curves obtained in the repacked soil cores and in the soil baskets were different from those obtained in the undisrupted soil cores. This indicates that the disruption of both structure and bulk density influenced the calibration of gypsum blocks. The effects were greater on the fine textured than on the coarse textured soils. The influence of bulk density was not important on a sandy loam soil. The variations in soil moisture obtained ranged from 1 to 6 per cent within the available water range.

Field Evaluation of 12 Soil Moisture Sensors on a Sandy Loam Soil in Lu’an, Subtropical Monsoon Climate Region, China

2012 ◽  
Vol 482-484 ◽  
pp. 372-375 ◽  
Author(s):  
Jing Cai Wang ◽  
Zi Qiang Xia ◽  
Ji Xing Wang ◽  
Zhi Hua Lu
Keyword(s):  
Soil Moisture ◽  
Large Scale ◽  
Sandy Loam ◽  
Sandy Loam Soil ◽  
Performance Study ◽  
Monsoon Climate ◽  
Climate Region ◽  
Soil Moisture Sensors ◽  
Loam Soil ◽  
Subtropical Monsoon Climate

An in situ field test with three indices of stability, sensitivity and accuracy on 12 soil moisture sensors was carried out in a sandy loam soil located in Lu’an at the subtropical monsoon climate region (China). The results showed that the majority of sensors were above 0.98 with a higher stability degree except for HT-DR-601(0.348) and DZN3 (0.661). Almost all sensors had a sensitive response to a certain amount of precipitation but Hydra Probe II was an exception. Trime-pico, SM300, ML2X, SWR6 and DH-FDR had a higher accuracy than 0.785, while DZN3 and HT-DR-601 were very lower. The mean differences of SM300, Trime-pico and Uni_SM were between -1% and 0, while HTSMS-02, DH-FDR, SWR6, ML2X, MP-4C and MP-323 were between -5% and -1%. DZN3 had the largest values of -17.8%. Finally, SM300, Trime-pico, ML2X, SWR6 and DH-FDR were got scores above 9 points while MP-323 and Uni_SM were above 8.4, showing an outstanding performance. The field performance study could provide some choices for the large-scale filed applications and the drought monitoring system.

Influence of Soil Moisture on Phytotoxicity of Cinmethylin to Various Crops

Weed Science ◽  
1991 ◽  
Vol 39 (3) ◽  
pp. 402-407 ◽  
Author(s):  
Steven G. Russell ◽  
Thomas J. Monaco ◽  
Jerome B. Weber
Keyword(s):  
Soil Moisture ◽  
Plant Species ◽  
Sandy Loam ◽  
Field Trials ◽  
Sandy Loam Soil ◽  
Moist Soil ◽  
Snap Bean ◽  
Crop Injury ◽  
Loam Soil ◽  
Dry Soil

Field trials were conducted in 1986 and 1987 to determine the effects of moisture on cinmethylin activity. The herbicide was applied preemergence at rates of 0.0, 0.3, 0.6, and 0.9 kg ai ha−1to both dry and moist sandy loam soil, followed by varying irrigation regimes. Plant species used in the study included soybean, snap bean, cotton, peanut, and cucumber. Peanut was the most tolerant to cinmethylin, followed by cotton, soybean, snap bean, and cucumber. When cinmethylin was applied to a moist soil, less crop injury resulted than when it was applied to a dry soil. If 7.6 cm of water was applied shortly after cinmethylin application to a dry soil, severe crop injury occurred. When 2.5 cm of irrigation was applied within 8 h or at 5 days after cinmethylin application to a dry soil, crop injury was reduced when compared to applying 7.6 cm irrigation.

Influence of Soil Moisture on Tolerance of Corn to Cyanazine

Weed Science ◽  
1975 ◽  
Vol 23 (6) ◽  
pp. 522-524 ◽  
Author(s):  
A. D. Kern ◽  
W. F. Meggitt ◽  
Donald Penner
Keyword(s):  
Zea Mays ◽  
Soil Moisture ◽  
Plant Growth ◽  
Sandy Loam ◽  
Dry Weight ◽  
Root Uptake ◽  
Sandy Loam Soil ◽  
High Soil Moisture ◽  
High Soil ◽  
Loam Soil

Tolerance of corn (Zea maysL.) to cyanazine {2-[[4-chloro-6-(ethylamino)-s-triazin-2-yl] amino]-2-methylpropionitrile} and atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] was compared when grown in Conover sandy loam soil. Reductions in seedling dry weight were obtained under both low and high soil moisture following preemergence and postemergence applications of cyanazine allowed to contact both plants and soil. During periods of active plant growth high soil moisture is favorable for rapid root uptake of cyanazine which causes injury to corn.

Complex Dielectric Permittivity of Sandy Loam as a Function of Salinity and Biomass at Microwaves

2013 ◽  
Vol 209 ◽  
pp. 116-120 ◽  
Author(s):  
Arun Sharma ◽  
K.C. Pancholi ◽  
S.P. Bhatnagar
Keyword(s):  
Soil Moisture ◽  
Dielectric Permittivity ◽  
Sandy Loam ◽  
Strong Dependence ◽  
Normal Incidence ◽  
Complex Dielectric Permittivity ◽  
Network Analyzer ◽  
Frequency Range ◽  
Moisture Contents ◽  
Loam Soil

Real and Imaginary parts of Complex Dielectric Permittivity (ε’ and ε” ) of Sandy Loam soil have been measured in the frequency range 150 MHz – 2.4 GHz using a Vector Network Analyzer at varied Moisture contents, Salinity and Biomass. The Emissivity of the soil for normal incidence was also calculated from measured values of Complex Permittivity. The measured permittivity data show strong dependence on moisture content. Salinity causes higher permittivity and dielectric loss. Biomass appears to enhance the permittivity data due to increase in porosity of the soil. The emissivity of the soil was observed to decrease with increasing soil moisture and soil salinity, but it increases with biomass.

scholarly journals Water consumption and soil moisture distribution in melon crop with mulching and in a protected environment

2013 ◽  
Vol 35 (2) ◽  
pp. 555-564 ◽  
Author(s):  
Rodrigo Otávio Câmara Monteiro ◽  
Rubens Duarte Coelho ◽  
Priscylla Ferraz Câmara Monteiro ◽  
Jan Whopmans ◽  
Bernd Lennartz
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Water Depth ◽  
Sandy Loam ◽  
Sandy Loam Soil ◽  
Moisture Distribution ◽  
Water Evaporation ◽  
Moisture Variation ◽  
Loam Soil ◽  
Crop Cycle

Mulching has become an important technique for land cover, but there are some technical procedures which should be adjusted for these new modified conditions to establish optimum total water depth. It is also important to observe the soil-water relations as soil water distribution and wetted volume dimensions. The objective of the present study was to estimate melon evapotranspiration under mulching in a protected environment and to verify the water spatial distribution around the melon root system in two soil classes. Mulching provided 27 mm water saving by reducing water evaporation. In terms of volume each plant received, on average, the amount of 175.2 L of water in 84 days of cultivation without mulching, while when was used mulching the water requirement was 160.2 L per plant. The use of mulching reduced the soil moisture variability throughout the crop cycle and allowed a greater distribution of soil water that was more intense in the clay soil. The clayey soil provided on average 43 mm more water depth retention in 0.50 m soil deep relative to the sandy loam soil, and reduced 5.6 mm the crop cycle soil moisture variation compared to sandy loam soil.

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