scholarly journals PREDICTION OF LONG-TERM DISPLACEMENTS OF PILE FOUNDATION WITH SOIL-WATER COUPLING ELASTO-PLASTIC FEM

2007 ◽  
Vol 63 (4) ◽  
pp. 1041-1053
Author(s):  
Koichiro DANNO ◽  
Makoto KIMURA ◽  
Yugo SUZUKI
Keyword(s):  
1992 ◽  
Vol 26 (10) ◽  
pp. 2005-2011 ◽  
Author(s):  
Claus Beier ◽  
Karin Hansen ◽  
Per Gundersen ◽  
Bjoern R. Andersen ◽  
Lennart Rasmussen
Keyword(s):  

Weed Science ◽  
2016 ◽  
Vol 64 (4) ◽  
pp. 596-604
Author(s):  
Logan G. Vaughn ◽  
Mark L. Bernards ◽  
Timothy J. Arkebauer ◽  
John L. Lindquist

The supply of soil resources is critical for the establishment and long-term competitive success of a plant species. Although there is considerable research on the effects of water supply on crop growth and productivity, there is little published research on the comparative response of crops and weeds to limiting soil water supply. The objective of this research was to determine the growth and transpiration efficiency of corn and velvetleaf at three levels of water supply. One corn or velvetleaf plant was grown in a large pot lined with plastic bags. When seedlings reached 10 cm, bags were sealed around the base of the plant, so the only water loss was from transpiration. Daily transpiration was measured by weighing the pots at the same time each day. The experiment was conducted in the fall of 2007 and in the spring of 2008. Four replicates of each species–water treatment were harvested periodically to determine biomass accumulation and leaf area. The relationship between cumulative aboveground biomass and water transpired was described using a linear function in which the slope defined the transpiration efficiency (TE). Corn TE was greater than velvetleaf TE in all treatments during both trials. In the fall trial, corn TE was 6.3 g kg–1, 47% greater than that of velvetleaf TE. In the spring trial, TEs of both species were lower overall, and corn TE increased with declining water supply. Corn produced more biomass and leaf area than velvetleaf did at all water-supply levels. Velvetleaf partitioned more biomass to roots compared with shoots during early growth than corn did. The ability of corn to generate more leaf area and its investment in a greater proportion of biomass into root growth at all levels of water supply may enable it to more-effectively avoid velvetleaf interference under all levels of soil-water supply.


2014 ◽  
Vol 186 (11) ◽  
pp. 7753-7753
Author(s):  
Liisa Ukonmaanaho ◽  
Mike Starr ◽  
Antti-Jussi Lindroos ◽  
Tiina M. Nieminen
Keyword(s):  

2002 ◽  
Vol 1 (2) ◽  
pp. 310-315 ◽  
Author(s):  
J. B. Sisson ◽  
G. W. Gee ◽  
J. M. Hubbell ◽  
W. L. Bratton ◽  
J. C. Ritter ◽  
...  

2012 ◽  
Vol 59 (No. 1) ◽  
pp. 1-7 ◽  
Author(s):  
B. Wang ◽  
W. Liu ◽  
Q. Xue ◽  
T. Dang ◽  
C. Gao ◽  
...  

The objective of this study was to investigate the effect of nitrogen (N) management on soil water recharge, available soil water at sowing (ASWS), soil water depletion, and wheat (Triticum aestivum L.) yield and water use efficiency (WUE) after long-term fertilization. We collected data from 2 experiments in 2 growing seasons. Treatments varied from no fertilization (CK), single N or phosphorus (P), N and P (NP), to NP plus manure (NPM). Comparing to CK and single N or P treatments, NP and NPM reduced rainfall infiltration depth by 20–60 cm, increased water recharge by 16–21 mm, and decreased ASWS by 89–133 mm in 0–300 cm profile. However, crop yield and WUE continuously increased in NP and NPM treatments after 22 years of fertilization. Yield ranged from 3458 to 3782 kg/ha in NP or NPM but was 1246–1531 kg/ha in CK and single N or P. WUE in CK and single N or P treatments was < 6 kg/ha/mm but increased to 12.1 kg/ha/mm in a NP treatment. The NP and NPM fertilization provided benefits for increased yield and WUE but resulted in lower ASWS. Increasing ASWS may be important for sustainable yield after long-term fertilization.


1991 ◽  
Vol 31 (5) ◽  
pp. 645 ◽  
Author(s):  
GM Murray ◽  
DP Heenan ◽  
AC Taylor

The incidence of take-all of wheat, caused by Gaeumannomyces graminis var. tritici (Ggt), and eyespot, caused by Tapesia yallundae, was examined in a long-term rotation-tillage experiment at Wagga Wagga, N.S.W. Take-all occurred in years of higher August-October rainfall from 1979 to 1984. In years with take-all, soil water in the upper 20 cm was estimated to be above permanent wilting point for the growing season. Eyespot was associated with above-average rainfall during winter and spring and was more prevalent where residues of wheat or grasses were retained. After the severe drought of 1982, take-all developed to high levels in 1983 in wheat that followed wheat, lupins or pasture when stubble was retained, but was reduced in 1984 after lupins. Take-all was reduced in the lupin-wheat rotations by removing stubble through burning or by early incorporation of stubble. Take-all incidence was less in wheat that followed grazed pasture than after mown pasture. Where stubble was retained, Ggt survived on stubble from wheat in 1981, through the drought of 1982, to infect wheat in 1983, but inoculum did not survive on stubble through the wet season of 1983 to infect wheat in 1984. Regression analysis indicated that take-all was negatively correlated with yield but eyespot was not. Take-all reduced yield by reducing kernel mass in 1 year and by reducing kernels per cm2 in 2 other years. Soil water conditions that were associated with take-all development from 1979 to 1984 occurred in 50% of years from 1960 to 1989.


1990 ◽  
Vol 70 (2) ◽  
pp. 125-136 ◽  
Author(s):  
C. CHANG ◽  
T. G. SOMMERFELDT ◽  
T. ENTZ ◽  
D. R. STALKER

Nineteen years of soil moisture content data at Lethbridge and two locations near Turin (Turin 1 and Turin 2) in southern Alberta were examined to evaluate the efficiency of follow for conserving moisture, and to calculate the long-term mean amount of water recharge during growing and nongrowing seasons under a fallow-cereal, 2-yr rotation and a continuous cropping system. Soil samples were taken annually from 1969 to 1987 to a depth of 120 cm in 30-cm intervals in the spring (early May) and fall (late September). A method for testing differences of means between nonstandard data using localized uncertainty associated with sliding polynomial smoothing was used to test for differences in the soil moisture contents due to cultural practices. The available soil moisture content of the soil to 120-cm depth was at least 50% of available water-holding capacity (AWHC) of the profile for the fallow treatment at Lethbridge and Turin 2, and, except in some years, at Turin 1. At seeding time, there was an average of 69 mm more available water (AW) in the fallow field than in the continuous cropping field at Lethbridge and 30, 35 and 27 mm more AW in the fallow field than in the fresh stubble field of a fallow-cereal, 2-yr rotation for Lethbridge, Turin 1 and Turin 2, respectively. The overall mean precipitation conserved as soil moisture for the fallow-cereal rotation practice was 23, 29 and 23% for Lethbridge, Turin 1 and Turin 2, respectively. The significantly higher soil water content at the 90- to 120-cm depth for the fallow field than for other fields during various periods of time indicates that the soil water recharge from precipitation might be deeper in the fallow field than in continuous cropping and fresh stubble of fallow-cereal rotation fields. The deeper soil water recharge could increase the available soil moisture for crop production and it could also contribute to ground water recharge. Key words: Soil water, available water content, continuous cropping, summerfallow


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